FlexShares Trust

FlexShares® ESG & Climate Emerging

Markets Core Index Fund

Ticker: FEEM

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Northern Trust ESG & Climate Emerging Markets Core IndexSM (the “Underlying Index”).

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Under the Fund’s Investment Advisory Agreement, the Fund is responsible for the following expenses: interest expenses, brokerage commissions and other trading expenses, fees and expenses of the independent trustees and their independent legal counsel, taxes and other extraordinary costs such as litigation and other expenses not incurred in the ordinary course of business. You will also incur usual and customary brokerage commissions and fees to financial intermediaries when buying or selling shares of the Fund in the secondary market, which are not reflected in the example that follows:

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.18%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.19%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.18%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.18%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 Year	$18
3 Years	$60
5 Years	$106
10 Years	$242

Portfolio Turnover. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. Portfolio turnover may vary from year to year, as well as within a year. During the most recent fiscal year, the Fund’s portfolio turnover rate was 36% of the average value of its portfolio.

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of companies that exhibit certain environmental, social and governance (“ESG”) characteristics, while also seeking to provide broad-market, core exposure to publicly traded equity securities issued by companies domiciled in emerging market countries. The Underlying Index is designed to minimize tracking differences relative to the Northern Trust Emerging Markets Large Cap IndexSM (the “Parent Index”) while also seeking (a) an aggregate higher scoring of certain ESG characteristics, as measured by the Northern Trust ESG Vector Score (“ESG Vector Score”) described below, and (b) reduction of aggregate climate-related risk, as measured by certain carbon-related risk metrics, each relative to the Parent Index. The Underlying Index also excludes certain companies by using controversial business involvement and norms-based screens.

The Parent Index is a sub-index of the Northern Trust Global IndexSM, where eligible securities are limited to those of companies that are domiciled in emerging market countries and designated as large- or mid-capitalization

FlexShares® ESG & Climate Emerging Markets Core Index Fund (cont.)

companies by NTI, in its capacity as Index Provider (the “Index Provider”). As of December 31, 2023, the Index Provider classifies the following as emerging market countries: Brazil, Chile, China, Colombia, Czech Republic, Egypt, Greece, Hungary, India, Indonesia, Kuwait, Malaysia, Mexico, Morocco, Peru, Philippines, Poland, Qatar, Saudi Arabia, South Africa, South Korea, Taiwan, Thailand, Turkey and United Arab Emirates.

The Index Provider applies an ESG Vector Score to each of the companies in the Parent Index. The ESG Vector Score is designed to rank companies based on their management of and exposure to material ESG metrics as defined by the Sustainability Accounting Standards Board (“SASB”) Standards and a corporate governance score for each company. NTI calculates and maintains ESG Vector Scores for companies using data from third-party data providers. The SASB Standards identify financially material ESG issues for a company based on its industry classification within the following five dimensions: (i) environmental; (ii) social capital; (iii) human capital; (iv) business model and innovation; and (v) leadership and governance. The preliminary ESG score is then adjusted up or down based on a quantitative assessment of how a company is managing the risks associated with those material ESG issues relative to its peers based on the recommendations of the Task Force on Climate-related Financial Disclosures to evaluate a company through governance, strategy and risk management lenses. The adjusted ESG score generates 80% of the ESG Vector Score. Finally, a distinct corporate governance score is applied to each company with respect to its (i) board and management quality and integrity; (ii) board structure; (iii) ownership and shareholder rights; (iv) remuneration; (v) financial reporting; and (vi) stakeholder governance, which generates 20% of the ESG Vector Score.

In addition to applying the ESG Vector Score, the Index Provider uses data from Institutional Shareholder Services ESG Solutions to assess carbon emissions intensity, carbon reserves and a carbon risk rating for each company. Carbon emissions intensity measures (i) direct greenhouse gas emissions from sources controlled or owned by the company (e.g., emissions associated with fuel combustion in boilers, furnaces, or vehicles); and (ii) indirect greenhouse gas emissions associated with the purchase of electricity, steam, heat or cooling against sales by the company. Carbon reserves measure the total estimated greenhouse gas

emissions attributable to a company’s fossil fuel reserve assets. The ISS Carbon Risk Rating provides an assessment of a company’s ability to mitigate the risks of transition to a lower carbon economy based on its specific baseline carbon risk exposure.

At the time of each reconstitution of the Underlying Index, the Index Provider uses an optimization process to select and weight securities in the Parent Index to seek to (i) minimize the potential for tracking differences for the Underlying Index; (ii) increase the aggregate ESG Vector Score for the companies in the Underlying Index; (iii) reduce the aggregate carbon emissions intensity and aggregate carbon reserves of the companies in the Underlying Index; and (iv) improve the aggregate carbon risk rating of the companies in the Underlying Index, each relative to the Parent Index. It is possible that the Underlying Index will include (and therefore the Fund could invest in) securities that, individually, have a low ESG Vector Score or high carbon-related risk relative to the aggregate ESG score or carbon-related risk of the Parent Index. The optimization also includes region, country, sector, industry group, constituent, liquidity, turnover and weight constraints so that these characteristics in the Underlying Index vary within acceptable bands relative to the Parent Index.

Certain eligible securities are excluded from the Underlying Index by the Index Provider, using proprietary screening definitions and data from Sustainalytics and other independent ESG data providers, which may change from time to time. Excluded companies include those which are involved in (i) verified infringement of established international initiatives and guidelines, including United Nations Global Compact Principles and Organisation for Economic Co-operation and Development (OECD) Guidelines for Multinational Entities; (ii) the production of tobacco; and (iii) manufacturing of controversial weapons. Excluded companies also include those which derive a certain percentage of revenue (e.g., 5% or more) from (a) manufacturing of civilian firearms; (b) manufacture, retailing, and distribution of small arms (assault and non-assault) weapons or components; (c) manufacturing of conventional weapons or providing support services through military contracting; (d) thermal coal extraction; (e) coal-fired energy generation; (f) oil sands and shale; (g) arctic oil with weak management of carbon within their products and services; (h) the retail sale of tobacco and tobacco

FlexShares® ESG & Climate Emerging Markets Core Index Fund (cont.)

related products or services; and (i) the running of private prisons. For issuers domiciled in emerging markets, an additional governance screen is applied and companies that do not meet the following criteria are ineligible: companies with scores that fall below the emerging market company average in the corporate governance categories of board structure, ownership and shareholder rights, remuneration, and audit and financial reporting. The above-described exclusionary screens are applied with each reconstitution of the Underlying Index.

As of December 31, 2023, the Underlying Index was comprised of 253 constituents with market capitalizations ranging from $1.7 billion to $475 billion. The Underlying Index is reconstituted quarterly under normal market conditions. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

NTI uses a representative sampling strategy to manage the Fund. “Representative sampling” is investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index. The Fund may or may not hold all of the securities that are included in the Underlying Index. The Fund reserves the right to invest in substantially all of the securities in its Underlying Index in approximately the same proportions (i.e., replication) if NTI determines that it is in the best interest of the Fund.

Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index and in American Depositary Receipts (“ADRs”) and Global Depositary Receipts (“GDRs”) (collectively “Depositary Receipts”) based on the securities in the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts, options on futures contracts and forward currency contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index. The Fund usually, but not always, pur

sues a strategy of being fully invested by exposing all or a portion of its cash to the performance of certain markets by purchasing index futures contracts (also known as “equitization”). This is intended to cause the Fund to perform as though its cash were actually invested in those markets. This futures exposure may or may not match the Fund’s Underlying Index and create indirect exposure to companies that have been excluded from the Underlying Index. The Fund will not invest directly in securities that have been excluded from the Fund’s Underlying Index.

The Underlying Index is created and sponsored by NTI, as the Index Provider. NTI also serves as the investment adviser to the Fund. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

The Fund is “non-diversified” under the Investment Company Act of 1940 (“1940 Act”), as amended, and may invest more of its assets in fewer issuers than “diversified” funds.

From time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular countries or geographic regions. As of December 31, 2023, the Fund focused its investments in China, Taiwan, India, South Korea and Brazil.

Principal Risks

FlexShares® ESG & Climate Emerging Markets Core Index Fund (cont.)

ESG Investment Risk is the risk that because the Index Provider includes and excludes issuers and assigns weights to issuers in the Underlying Index by applying non-financial factors, the Fund may underperform the broader equity market or other funds that do or do not use ESG factors, scores, or screens in their securities selection process, or use a different ESG methodology. The ESG methodology of the Underlying Index will affect the Fund’s exposure to certain companies and sectors and may adversely affect the Fund’s performance depending on whether such companies and sectors are in or out of favor. Although the Underlying Index is designed to measure a portfolio of companies with certain ESG characteristics, there is no assurance that every security in the Underlying Index or Fund will have ESG characteristics or that companies that have historically exhibited such characteristics will continue to exhibit such characteristics. There is also the risk that the Fund may have indirect exposure to companies that have been excluded from the Underlying Index through its use of certain derivative instruments.

Currently, there is a lack of common industry standards relating to the development and application of ESG criteria, which may make it difficult to compare the Fund’s principal investment strategies with the investment strategies of other funds that integrate certain ESG criteria. The subjective value that investors may assign to certain types of ESG characteristics may differ substantially from that of the assessment by the Index Provider or a data provider. Investors can differ in their views of what constitutes positive or negative ESG characteristics. As a result, the Fund may invest in companies that do not reflect the beliefs and values of any particular investor. A company included in the Underlying Index may not exhibit positive or favorable ESG characteristics. The companies selected by the Index Provider as demonstrating certain ESG characteristics may not be the same companies selected by other index providers or investment managers as exhibiting those characteristics.

of the issuers of the securities included in the Fund’s Underlying Index. The Index Provider uses third-party data that it believes to be reliable, but it does not guarantee the accuracy of such third-party data. Data can vary across providers or within industries. ESG standards differ by region and industry, and a company’s ESG practices or the Index Provider’s or data providers’ assessment of a company’s ESG practices may change over time. Regulatory changes or interpretations regarding the definitions and/or use of ESG criteria could have a material adverse effect on the Fund’s ability to invest in accordance with its investment policies and/or achieve its investment objective.

Foreign Securities Risk is the risk that investing in foreign (non-U.S.) securities may result in the Fund experiencing more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies, due to less liquid markets and adverse economic, political, diplomatic, financial, and regulatory factors. Foreign governments may impose limitations on foreigners’ ownership of interests in local issuers, restrictions on the ability to repatriate assets, and may also impose taxes. Any of these events could cause the value of the Fund’s investments to decline. Foreign banks, agents and securities depositories that hold the Fund’s foreign assets may be subject to little or no regulatory oversight over, or independent evaluation, of their operations. Additional costs associated with investments in foreign securities may include higher custodial fees than those applicable to domestic custodial arrangements and transaction costs of foreign currency conversions. Unless the Fund has hedged its foreign currency exposure, foreign securities risk also involves the risk of negative foreign currency rate fluctuations, which may cause the value of securities denominated in such foreign currency (or other instruments through which the Fund has exposure to foreign currencies) to decline in value. Currency exchange rates may fluctuate significantly over short periods of time. Currency hedging strategies, if used, are not always successful. For instance, forward foreign currency exchange contracts, if used by the Fund, could reduce performance if there are unanticipated changes in currency exchange rates.

FlexShares® ESG & Climate Emerging Markets Core Index Fund (cont.)

than more developed markets. In addition, companies operating in emerging markets may be subject to lower trading volumes and greater price volatility than companies in more developed markets. Emerging market economies may be based on only a few industries, may be highly vulnerable to changes in local and global trade conditions, and may suffer from extreme and volatile debt burdens or inflation rates. Companies in emerging market countries generally may be subject to less stringent regulatory, disclosure, financial reporting, accounting, auditing and recordkeeping standards than companies in more developed countries. As a result, information, including financial information, about such companies may be less available and reliable, which can impede the Fund’s ability to evaluate such companies. Securities law and the enforcement of systems of taxation in many emerging market countries may change quickly and unpredictably, and the ability to bring and enforce actions (including bankruptcy, confiscatory taxation, expropriation, nationalization of a company’s assets, restrictions on foreign ownership of local companies, restrictions on withdrawing assets from the country, protectionist measures and practices such as share blocking), or to obtain information needed to pursue or enforce such actions, may be limited. Investments in emerging market securities may be subject to additional transaction costs, delays in settlement procedures, unexpected market closures, and lack of timely information.

Geographic Risk is the risk that if the Fund invests a significant portion of its total assets in certain issuers within the same country or geographic region, an adverse economic, business or political development affecting that country or region may affect the value of the Fund’s investments more, and the Fund’s investments may be more volatile, than if the Fund’s investments were not so concentrated in such country or region.

•China Investment Risk is the risk associated with investments in companies located or operating in China, such as nationalization, expropriation, or confiscation of property; alteration or discontinuation of economic reforms; and considerable degrees of economic, political and social instability. Investors in Chinese markets generally experience difficulties in obtaining information necessary for investigations into and/or litigation against Chinese companies, as well as in obtaining and/or enforcing judgements due to a lack of publicly available information; and there are gener

ally limited legal remedies for shareholders. Internal social unrest or confrontations with other neighboring countries, including military conflicts, may disrupt economic development in China and result in a greater risk of currency fluctuations, currency convertibility, interest rate fluctuations and higher rates of inflation. Export growth continues to be a major driver of China’s rapid economic growth. As a result, a reduction in spending on Chinese products and services, the institution of additional tariffs or other trade barriers, including as a result of heightened trade tensions between China and the U.S., or a downturn in any of the economies of China’s key trading partners may have an adverse impact on the Chinese economy. Any difficulties of the Public Company Accounting Oversight Board (“PCAOB”) to inspect audit work papers and practices of PCAOB-registered accounting firms in China with respect to their audit work of U.S. reporting companies may impose significant additional risks associated with investments in China. Certain securities issued by companies located or operating in China, such as China A-shares, are subject to trading restrictions and suspensions, quota limitations and sudden changes in those limitations, and operational, clearing and settlement risks.

•India Investment Risk is the risk associated with investments in companies located or operating in India, such as political and legal uncertainty, greater government control over the economy, currency fluctuations or blockage, and the risk of nationalization or expropriation of assets, which may result in higher potential for losses. Specifically, India’s strained relations with neighboring countries like Pakistan and China could result in geopolitical risk that has an adverse impact on the Indian economy and stock market. In addition, the Reserve Bank of India (“RBI”) has imposed limits on foreign ownership of Indian securities, which may limit the amount the Fund can invest in certain types of companies. Further, certain Indian regulatory approvals, including approvals from the Securities and Exchange Board of India, the RBI, the central government and the tax authorities (to the extent that tax benefits need to be utilized), may be required before the Fund can make investments in the securities of Indian companies. Capital gains from Indian securities may be subject to local taxation.

•Taiwan Investment Risk is the risk of investing in securities of Taiwanese issuers. Specifically, Taiwan’s geographic proximity and history of political contention with China have resulted in ongoing tensions between

FlexShares® ESG & Climate Emerging Markets Core Index Fund (cont.)

the two countries, which may materially affect the Taiwanese economy and its securities market. Investments in securities of Taiwanese companies are subject to Taiwan’s heavy dependence on exports. Reductions in spending on Taiwanese products and services, labor shortages, institution of tariffs or other trade barriers, or a downturn in any of the economies of Taiwan’s key trading partners, including the United States, may have an adverse impact on the Taiwanese economy and the values of Taiwanese companies.

Depositary Receipts Risk Foreign securities may trade in the form of depositary receipts. In addition to investment risks associated with the underlying issuer, depositary receipts may expose the Fund to additional risks associated with non-uniform terms that apply to depositary receipt programs, including credit exposure to the depository bank and to the sponsors and other parties with whom the depository bank establishes the programs, currency, political, economic, market risks and the risks of an illiquid market for depositary receipts. Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. Depositary receipts may not track the price of the underlying foreign securities on which they are based, may have limited voting rights, and may have a distribution subject to a fee charged by the depository. As a result, equity shares of the underlying issuer may trade at a discount or premium to the market price of the depositary receipts.

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile and underperform other asset classes and the general securities markets.

Mid Cap Stock Risk is the risk that stocks of mid-sized companies may be subject to more abrupt or erratic market movements than stocks of larger, more established companies, and may lack sufficient market liquidity. Mid-sized companies may have limited product lines or financial resources, and may be dependent upon a particular niche of the market, or may be dependent upon a small or inexperienced management group. Securities of smaller companies may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally the smaller the company size, the greater the risk.

Concentration Risk is the risk that, if the Fund is concentrated in a particular industry or group of industries, the Fund is likely to present more risks than a fund that is

broadly diversified over several industries or groups of industries. Compared to the broad market, an individual industry may be more strongly affected by changes in the economic climate, broad market shifts, moves in a particular dominant stock or regulatory changes.

Market Risk is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment could have a significant impact on the Fund and its investments and could result in the Fund’s shares trading at increased premiums or discounts to the Fund’s NAV. During periods of market disruption or other abnormal market conditions, the Fund’s exposure to the risks described elsewhere in this summary will likely increase.

Index Risk is the risk that the Fund would not necessarily buy or sell a security unless that security is added to or removed from, respectively, the Underlying Index, even if that security generally is underperforming, because unlike many investment companies, the Fund does not utilize an investing strategy that seeks returns in excess of the Underlying Index. Additionally, the Fund rebalances and/or reconstitutes its portfolio in accordance with the Underlying Index, and, therefore, any changes to the Underlying Index’s rebalance and/or reconstitution schedule will result in corresponding changes to the Fund’s rebalance and/or reconstitution schedule.

FlexShares® ESG & Climate Emerging Markets Core Index Fund (cont.)

ity to adjust its exposure to required levels in order to track its Index or cause delays in the Underlying Index's rebalancing schedule. During any such delay, it is possible that the Underlying Index, and, in turn, the Fund will deviate from the Underlying Index's stated methodology and therefore experience returns different than those that would have been achieved under a normal rebalancing or reconstitution schedule.

Sampling Risk is the risk that the Fund’s use of a representative sampling approach may result in increased tracking error because the securities selected for the Fund in the aggregate may vary from the investment profile of the Underlying Index. Additionally, the use of a representative sampling approach may result in the Fund holding a smaller number of securities than the Underlying Index, and, as a result, an adverse development to an issuer of securities that the Fund holds could result in a greater decline in NAV than would be the case if the Fund held all of the securities in the Underlying Index.

Authorized Participant Concentration Risk is the risk that the Fund may be adversely affected because it has a limited number of institutions that act as authorized participants (“Authorized Participants”). Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units (as defined below), Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting. This risk may be heightened because of its investments in non-U.S. securities.

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund’s holdings may not exhibit returns consistent with that characteristic or exposure.

Market Trading Risk is the risk that the Fund faces because its shares are listed on a securities exchange, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruption in the creation/redemption process of the Fund. ANY OF THESE FACTORS MAY LEAD TO THE FUND’S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

Trading in Fund shares may be halted due to market conditions or for reasons that, in the view of its listing exchange, make trading in the shares inadvisable. The market prices of Fund shares will generally fluctuate in accordance with changes in its NAV, changes in the relative supply of, and demand for, Fund shares, and changes in the liquidity, or the perceived liquidity, of the Fund’s holdings.

Derivatives Risk is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

•Futures Contracts Risk is the risk that there will be imperfect correlation between the change in market value of the Fund’s securities and the price of futures contracts, which may result in the strategy not working as intended; the possible inability of the Fund to sell or close out a futures contract at the desired time or price; losses due to unanticipated market movements, which potentially are unlimited; and the possible inability of NTI to correctly predict the direction of securities’ prices, interest rates, currency exchange rates and other economic factors, which may make the Fund’s returns more volatile or increase the risk of loss.

FlexShares® ESG & Climate Emerging Markets Core Index Fund (cont.)

between the options and the securities markets that cause a given transaction to fail to achieve its objectives. The successful use of options depends on the investment adviser’s ability to predict correctly future price fluctuations and the degree of correlation between the options and securities markets. Exchanges can limit the number of positions that can be held or controlled by the Fund or the investment adviser, thus limiting the ability to implement the Fund’s strategies.

•Forward Foreign Currency Contracts Risk is the risk that, if forward prices increase, a loss will occur to the extent that the agreed upon purchase price of the currency exceeds the price of the currency that was agreed to be sold.

New Fund Risk is the risk that the Fund will not grow to or maintain an economically viable size, in which case it may experience greater tracking error to its Underlying Index than it otherwise would at higher asset levels, or it could ultimately liquidate without shareholder approval. The timing of such liquidation may not be favorable and could have negative tax consequences for shareholders. From time to time, an Authorized Participant, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, may invest in the Fund and hold its investment for a specific period of time in order to facilitate commencement of the Fund’s operations or for the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund. The Fund’s Distributor does not maintain a secondary market in the shares.

Non-Diversification Risk is the risk that because the Fund is non-diversified and may invest a larger percentage of its assets in the securities of fewer issuers than a diversified fund, the Fund’s performance will be more vulnerable to changes in the market value of a single issuer or group of issuers, and more susceptible to risks associated with a single economic, political or regulatory occurrence.

Securities Lending Risk is the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. The Fund could also lose money in the event of a decline in the value of collateral provided for loaned securities or a decline in the value of any investments made with cash collateral.

Valuation Risk is the risk that the sale price the Fund could receive for a portfolio security may differ from the Fund’s valuation of the security, particularly for securities that trade in low volume or volatile markets or that are valued using a fair value methodology. In addition, the value of the securities in the Fund’s portfolio may change on days when shareholders will not be able to purchase or sell the Fund’s shares.

It is possible to lose money on an investment in the Fund.An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund by showing (A) changes in the Fund’s performance from year to year, (B) how the Fund’s average annual returns compare with those of a broad measure of market performance, and (C) an additional index with characteristics relevant to the Fund. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated information on the Fund’s performance results can be obtained by visiting flexshares.com.

Calendar Year Total Returns

For the period shown in the bar chart above:

Best Quarter (12/31/2023): 7.97%

Worst Quarter (9/30/2023): -3.32%

FlexShares® ESG & Climate Emerging Markets Core Index Fund (cont.)

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Since Inception of Fund	Inception Date of Fund
Before Taxes	9.13%	-1.35%	4/20/2022
After Taxes on Distributions	8.66%	-1.91%	—
After Taxes on Distributions and Sale of Shares	6.03%	-0.95%	—
MSCI Emerging Markets Index*	9.83%	-1.09%	—
Northern Trust ESG & Climate Emerging Markets Core IndexSM*	9.98%	-1.04%	—

Reflects no deduction for fees, expenses or taxes.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement plans. After-tax returns may exceed the return before taxes due to an assumed tax benefit from realizing a capital loss on a sale of Fund shares.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Robert Anstine, a Senior Vice President of NTI, and Alan Aung, a Vice President of NTI, have served as Portfolio Managers of the Fund since its inception in April 2022.

Purchase and Sale of Fund Shares

investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase shares of the Fund (bid) and the lowest price a seller is willing to accept for shares of the Fund (ask) when buying or selling shares in the secondary market (“the bid-ask spread”). Recent information, including information about the Fund’s NAV, market price, premiums and discounts, and bid-ask spreads, is included on the Fund’s website at flexshares.com.

Tax Information

The Fund’s distributions are generally taxable to you as ordinary income, qualified dividends, capital gains, or a combination of the three, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

Payments to Brokers-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), NTI and its related companies may pay the intermediary for activities related to the marketing and promotion of the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

FlexShares® Morningstar Global

Upstream Natural Resources Index Fund

Ticker: GUNR

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Morningstar® Global Upstream Natural Resources IndexSM (the “Underlying Index”).

Fees And Expenses Of The Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.46%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.47%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.46%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.46%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$47
3 Years	$150
5 Years	$262
10 Years	$590

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of equity securities that are traded in or are issued by companies classified as developed or emerging markets (including the U.S.), as determined by Morningstar, Inc. (the “Index Provider”) pursuant to its index methodology. To be eligible for inclusion in the Underlying Index, a security must be issued by a company that has significant economic interests in one of the following natural resource categories: energy, agriculture, precious or industrial metals, timber or water, as determined by the Index Provider pursuant to its index methodology (collectively, the “Natural Resources sector”). Securities determined to be within the Natural Resources sector are then excluded from the Underlying Index if (i) they have an average daily traded value of less than $1 million or (ii) for securities within the energy, agriculture or precious or industrial metals categories of the Natural Resources sector, they have a full market capitalization of less than $1 billion, or for securities within the timber or water categories of the Natural Resources sector, they have a full market capitalization of less than $500 million. Securities within the

FlexShares® Morningstar Global Upstream Natural Resources Index Fund (cont.)

Underlying Index are then weighted based on their float-adjusted market capitalization within each category of the Natural Resources sector, and weight caps are applied to limit exposure to any particular category within the Natural Resources sector, any individual security, the U.S. and emerging markets.

As of December 31, 2023, the Underlying Index was comprised of 120 issues with market capitalizations ranging from $959 million to $2.1 trillion. The Underlying Index is reconstituted on a semi-annual basis and is rebalanced quarterly. The Fund generally rebalances and reconstitutes its portfolio in accordance with the Underlying Index.

The Underlying Index is sponsored by the Index Provider, an organization that is independent of the Fund and NTI. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. As of December 31, 2023, the Underlying Index was concentrated in the Natural Resources sector. The components of the Underlying Index, and the degree to which these components represent certain industries or sectors, may change over time.

Principal Risks

Concentration Risk is the risk that, if the Fund is concentrated in a particular industry or group of industries, the Fund is likely to present more risks than a fund that is broadly diversified over several industries or groups of industries. Compared to the broad market, an individual industry may be more strongly affected by changes in the economic climate, broad market shifts, moves in a particular dominant stock or regulatory changes.

•Natural Resources Sector Risk is the risk that the Fund is subject to the risks associated with investment in companies within the Natural Resources sector in addition to the general risk of the stock market. Companies within the Natural Resources sector can be significantly

FlexShares® Morningstar Global Upstream Natural Resources Index Fund (cont.)

affected by events relating to U.S. and foreign political and economic developments and environmental and other government regulations, as well as other factors including, but not limited to: commodity price volatility, technological developments and natural or man-made disasters. Declines in the demand for, or prices of, natural resources generally would be expected to contribute to declines in the value of the Fund’s equity securities. Such declines may occur quickly and without warning and may negatively impact the value of the Fund and your investment.

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile and underperform other asset classes and the general securities markets.

Depositary Receipts Risk Foreign securities may trade in the form of depositary receipts. In addition to investment risks associated with the underlying issuer, depositary

receipts may expose the Fund to additional risks associated with non-uniform terms that apply to depositary receipt programs, including credit exposure to the depository bank and to the sponsors and other parties with whom the depository bank establishes the programs, currency, political, economic, market risks and the risks of an illiquid market for depositary receipts. Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. Depositary receipts may not track the price of the underlying foreign securities on which they are based, may have limited voting rights, and may have a distribution subject to a fee charged by the depository. As a result, equity shares of the underlying issuer may trade at a discount or premium to the market price of the depositary receipts.

Emerging Markets Risk is the risk that emerging markets are generally subject to greater market volatility, political, social and economic instability, uncertain trading markets and more governmental limitations on foreign investments than more developed markets. In addition, companies operating in emerging markets may be subject to lower trading volumes and greater price volatility than companies in more developed markets. Emerging market economies may be based on only a few industries, may be highly vulnerable to changes in local and global trade conditions, and may suffer from extreme and volatile debt burdens or inflation rates. Companies in emerging market countries generally may be subject to less stringent regulatory, disclosure, financial reporting, accounting, auditing and recordkeeping standards than companies in more developed countries. As a result, information, including financial information, about such companies may be less available and reliable, which can impede the Fund’s ability to evaluate such companies. Securities law and the enforcement of systems of taxation in many emerging market countries may change quickly and unpredictably, and the ability to bring and enforce actions (including bankruptcy, confiscatory taxation, expropriation, nationalization of a company’s assets, restrictions on foreign ownership of local companies, restrictions on withdrawing assets from the country, protectionist measures and practices such as share blocking), or to obtain information needed to pursue or enforce such actions, may be limited. Investments in emerging market securities may be subject to additional transaction costs, delays in settlement procedures, unexpected market closures, and lack of timely information.

FlexShares® Morningstar Global Upstream Natural Resources Index Fund (cont.)

•United Kingdom Investment Risk is the risk that investments in issuers located in the United Kingdom (“UK”) may subject the Fund to regulatory, political, currency, security and economic risk specific to the UK. The UK has one of the largest economies in Europe and is heavily dependent on trade with the European Union (“EU”). As a result, the UK economy may be impacted by changes to the economic health of EU member countries. In 2016, the UK voted to leave the EU (commonly known as “Brexit”), and on January 31, 2020, the UK officially withdrew from the EU. The precise impact on the UK’s economy as a result of its departure from the EU depends to a large degree on its ability to conclude favorable trade deals with the EU and other countries. While new trade deals may boost economic growth, such growth may not be able to offset the increased costs of trade with the EU resulting from the UK’s loss of its membership in the EU single market.

Tracking Error Risk is the risk that the Fund’s performance may vary from the performance of the Underlying Index as a result of creation and redemption activity, transaction costs, expenses and other factors. Market disruptions, regulatory restrictions or other abnormal market conditions could have an adverse effect on the Fund's ability to adjust its exposure to required levels in order to track its Index or cause delays in the Underlying Index's rebalancing schedule. During any such delay, it is possible that the Underlying Index, and, in turn, the Fund will deviate from the Underlying Index's stated methodology and therefore experience returns different than those that would have been achieved under a normal rebalancing or reconstitution schedule.

FlexShares® Morningstar Global Upstream Natural Resources Index Fund (cont.)

tion transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units (as defined below), Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting. This risk may be heightened because of its investments in non-U.S. securities.

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

Mid and Small Cap Stock Risk is the risk that stocks of mid-sized and smaller companies may be more volatile than stocks of larger, more established companies, and may lack sufficient market liquidity. Mid-sized and small companies may have limited product lines or financial resources, may be dependent upon a particular niche of the market, or may be dependent upon a small or inexperienced management group. Securities of smaller companies may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally the smaller the company size, the greater the risk.

FlexShares® Morningstar Global Upstream Natural Resources Index Fund (cont.)

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund by showing (A) changes in the Fund’s performance from year to year and (B) how the Fund’s average annual returns compare with those of a broad measure of market performance. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated information on the Fund’s performance results can be obtained by visiting flexshares.com.

Calendar Year Total Returns

For the periods shown in the bar chart above:

Best Quarter (6/30/2020): 21.62%

Worst Quarter (3/31/2020): -31.00%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Ten Year
Before Taxes	-1.72%	11.00%	5.19%
After Taxes on Distributions	-2.57%	10.01%	4.40%
After Taxes on Distributions and Sale of Shares	-0.48%	8.59%	3.96%
Morningstar® Global Upstream Natural Resources IndexSM*	-1.28%	11.62%	5.71%

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Robert Anstine, a Senior Vice President of NTI, and Brendan Sullivan, a Vice President of NTI, have served as Portfolio Managers of the Fund since October 2013 and June 2016, respectively.

Purchase and Sale of Fund Shares

The Fund is an exchange-traded fund (commonly referred to as an “ETF”). The Fund’s shares may be issued and redeemed only by certain large institutions, referred to as “Authorized Participants,” that enter into agreements with the Fund’s principal underwriter. Retail investors may acquire and sell Fund shares in the secondary market through a broker-dealer. The price of Fund shares is based on market price, and because ETF shares trade at market prices rather than NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). An investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase shares of the Fund (bid) and the lowest price a seller is willing to accept for shares of the Fund (ask) when buying or selling shares in the secondary market (“the bid-ask spread”). Recent information, including information about the Fund’s NAV, market price, premiums and discounts, and bid-ask spreads, is included on the Fund’s website at flexshares.com.

Tax Information

FlexShares® Morningstar Global Upstream Natural Resources Index Fund (cont.)

Payments to Brokers-Dealers and Other Financial Intermediaries

FlexShares® STOXX® Global Broad

Infrastructure Index Fund

Ticker: NFRA

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the STOXX® Global Broad Infrastructure Index (the “Underlying Index”).

Fees And Expenses Of The Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.47%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.48%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.47%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.47%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$48
3 Years	$153
5 Years	$268
10 Years	$603

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of companies that, in aggregate, offer broad exposure to publicly traded developed- and emerging-market infrastructure companies, including U.S. companies, as defined by STOXX Ltd. (the “Index Provider”) pursuant to its index methodology. In addition, NTI believes that the companies in the Underlying Index have the potential to generate income through dividend and other payments received.

To be eligible for inclusion in the Underlying Index, companies must generate at least 50% of their respective revenues from the ownership, development, construction, financing or operation of infrastructure-related assets in the following five supersector groups: (i) communication (i.e., cable and satellite, data centers, wireless, wireless towers and wireline); (ii) energy (i.e., energy utilities and mid-stream energy); (iii) government outsourcing/social (i.e., correctional facilities, hospitals and postal services); (iv) transportation (i.e., air transportation, passenger transportation, rail transportation, road transportation and water transportation); and (v) utilities (i.e., waste management

FlexShares® STOXX® Global Broad Infrastructure Index Fund (cont.)

and water utilities). Securities must also meet certain minimum liquidity requirements. Eligible securities are then selected based on largest free-float adjusted market capitalization, with a maximum of 40 securities from each supersector group and with a cap on the number of constituent securities among the sector groups of each supersector group. To prevent companies, supersectors and countries from dominating the portfolio, the Underlying Index also includes constituent, supersector and country weight caps (“Weight Caps”). Constituents of the Underlying Index may include common and preferred stocks, publicly-traded units of master limited partnerships (“MLPs”) and real estate investment trusts (“REITs”).

As of December 31, 2023, the Underlying Index was comprised of 171 issues with market capitalizations ranging from $87 million to $176 billion. The Underlying Index is reconstituted on an annual basis and the Weight Caps are applied on a quarterly basis. The Fund generally reconstitutes or otherwise modifies its portfolio in accordance with the Underlying Index.

options on futures contracts and forward currency contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. As of December 31, 2023, the Underlying Index was concentrated in infrastructure-related companies in the communication, industrials and utilities subsector groups. The components of the Underlying Index, and the degree to which these components represent certain industries or sectors, may change over time.

Principal Risks

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile and underperform other asset classes and the general securities markets.

FlexShares® STOXX® Global Broad Infrastructure Index Fund (cont.)

REIT Risk is the risk that the Fund’s investments may be affected by factors affecting REITs and the real estate sector generally. Investing in REITs involves certain unique risks in addition to those risks associated with investing in the real estate industry in general. REITs whose underlying properties are concentrated in a particular industry or geographic region are also subject to risks affecting such industries and regions. REITs may have limited financial resources, may trade less frequently and in lower volume, engage in dilutive offerings or become more volatile than other securities. By investing in REITs through the Fund, a shareholder will bear expenses of the REITs in addition to expenses of the Fund. In addition, REITs could possibly fail to (i) qualify for favorable tax treatment under applicable tax law, or (ii) maintain their exemption from registration under the Investment Company Act of 1940.

MLP Risk is the risk that accompanies an investment in MLP units. The risks of investing in an MLP are similar to those of investing in a partnership, including more flexible governance structures, which could result in less protection for investors, such as the Fund, than investments in a corporation. An investor in an MLP normally would not be liable for the debts of the MLP beyond the amount that the investor has contributed but may not be shielded from liability to the same extent that a shareholder of a corporation would be. MLPs are also subject to risks related to potential conflicts of interest between the MLP and the MLP’s general partner and cash flow risks. MLPs that concentrate in a particular industry or a particular geographic region are subject to risks associated with such industry or region. MLPs may also be sensitive to changes in interest rates and during periods of interest rate volatility, limited capital markets access and/or low commodities pricing and may not provide attractive returns.

MLP Tax Risk. An MLP is a public limited partnership or limited liability company taxed as a partnership under the Internal Revenue Code of 1986. MLPs taxed as partnerships do not pay U.S. federal income tax at the partnership level, subject to the application of certain partnership audit rules. A change in current tax law, or a change in the underlying business mix of a given MLP, however, could result in an MLP being classified as a corporation for U.S. federal income tax purposes, which would have the effect of reducing the amount of cash available for distribution by the MLP and, as a result, could result in a reduction of the value of the Fund’s investment (and the Fund), and, consequently, lower income.

Emerging Markets Risk is the risk that emerging markets are generally subject to greater market volatility, political, social and economic instability, uncertain trading markets

FlexShares® STOXX® Global Broad Infrastructure Index Fund (cont.)

and more governmental limitations on foreign investments than more developed markets. In addition, companies operating in emerging markets may be subject to lower trading volumes and greater price volatility than companies in more developed markets. Emerging market economies may be based on only a few industries, may be highly vulnerable to changes in local and global trade conditions, and may suffer from extreme and volatile debt burdens or inflation rates. Companies in emerging market countries generally may be subject to less stringent regulatory, disclosure, financial reporting, accounting, auditing and recordkeeping standards than companies in more developed countries. As a result, information, including financial information, about such companies may be less available and reliable, which can impede the Fund’s ability to evaluate such companies. Securities law and the enforcement of systems of taxation in many emerging market countries may change quickly and unpredictably, and the ability to bring and enforce actions (including bankruptcy, confiscatory taxation, expropriation, nationalization of a company’s assets, restrictions on foreign ownership of local companies, restrictions on withdrawing assets from the country, protectionist measures and practices such as share blocking), or to obtain information needed to pursue or enforce such actions, may be limited. Investments in emerging market securities may be subject to additional transaction costs, delays in settlement procedures, unexpected market closures, and lack of timely information.

Depositary Receipts Risk. Foreign securities may trade in the form of depositary receipts. In addition to investment risks associated with the underlying issuer, depositary receipts may expose the Fund to additional risks associated with non-uniform terms that apply to depositary receipt programs, including credit exposure to the depository bank and to the sponsors and other parties with whom the depository bank establishes the programs, currency, political, economic, market risks and the risks of an illiquid market for depositary receipts. Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. Depositary receipts may not track the price of the underlying foreign securities on which they are based, may have limited voting rights, and may have a distribution subject to a fee charged by the depository. As a result, equity shares of the underlying issuer may trade at a discount or premium to the market price of the depositary receipts.

•Canada Investment Risk. is the risk that the Fund is particularly sensitive to political, economic and social conditions in affecting Canada. The Canadian economy is especially dependent on the demand for, and supply of, natural resources, and the Canadian market is relatively concentrated in issuers involved in the production and distribution of natural resources, particularly the production of metals. Any adverse events that affect Canada’s major industries may have a negative impact on the overall Canadian economy and the Fund.

FlexShares® STOXX® Global Broad Infrastructure Index Fund (cont.)

lying Index. Additionally, the Fund rebalances and/or reconstitutes its portfolio in accordance with the Underlying Index, and, therefore, any changes to the Underlying Index’s rebalance and/or reconstitution schedule will result in corresponding changes to the Fund’s rebalance and/or reconstitution schedule.

NAV and possibly face trading halts and/or delisting. This risk may be heightened because of its investments in non-U.S. securities.

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

FlexShares® STOXX® Global Broad Infrastructure Index Fund (cont.)

a project no longer economical; (c) macroeconomic factors such as low gross domestic product (“GDP”) growth or high nominal interest rates will raise the average cost of infrastructure funding; (d) government regulation may affect rates charged to infrastructure customers; (e) government budgetary constraints will impact infrastructure projects; (f) special tariffs will be imposed; and (g) changes in tax laws, regulatory policies or accounting standards could be unfavorable. Other risks include environmental damage due to a company’s operations or an accident, a natural disaster, changes in market sentiment towards infrastructure and terrorist acts. Any of these events could cause the value of the Fund’s or Underlying Fund’s investments in infrastructure-related companies to decline.

•Options Contracts Risk Options contracts give the holder of the option the right to buy (or to sell) a position in a security or in a contract to the writer of the option, at a certain price. They are subject to correlation risk because there may be an imperfect correlation between the options and the securities markets that cause a given transaction to fail to achieve its objectives. The successful use of options depends on the investment adviser’s ability to predict correctly future price fluctuations and the degree of correlation between the options and securities markets. Exchanges can limit the number of positions that can be held or controlled by the Fund or the investment adviser, thus limiting the ability to implement the Fund’s strategies.

Interest Rate Risk is the risk that during periods of rising interest rates, the Fund’s yield (and the market value of its securities) will tend to be lower than prevailing market rates; in periods of falling interest rates, the Fund’s yield (and the market value of its securities) will tend to be higher. Increases in interest rates typically lower the present value of a REIT’s future earnings stream, and may make financing property purchases and improvements more costly. Because the market price of REIT stocks may change based upon investors’ collective perceptions of future earnings, the value of the Fund may decline when investors anticipate or experience rising interest rates.

In general, securities with longer maturities or durations are more sensitive to interest rate changes. Changing interest rates, including rates that fall below zero, may have unpredictable effects on the markets and the Fund’s investments, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Fund, and may detract from Fund performance. A low or negative interest rate environment could cause the Fund’s earnings to fall below the Fund’s expense ratio, resulting in a low or negative yield and a decline in the Fund’s NAV. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Fund. During periods when inflation rates are high or rising, or during periods of low interest rates, the Fund may be subject to a greater risk of rising interest rates.

FlexShares® STOXX® Global Broad Infrastructure Index Fund (cont.)

value of collateral provided for loaned securities or a decline in the value of any investments made with cash collateral.

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund by showing (A) changes in the Fund’s performance from year to year and (B) how the Fund’s average annual returns compare with those of a broad measure of market performance. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated information on the Fund’s performance results can be obtained by visiting flexshares.com.

Calendar Year Total Returns

For the period shown in the bar chart above:

Best Quarter (3/31/2019): 13.57%

Worst Quarter (3/31/2020): -19.69%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Ten Year
Before Taxes	8.94%	6.81%	5.17%
After Taxes on Distributions	8.31%	6.18%	4.51%
After Taxes on Distributions and Sale of Shares	5.79%	5.30%	4.03%
STOXX® Global Broad Infrastructure Index*	8.81%	6.69%	5.08%

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Robert Anstine, a Senior Vice President of NTI, and Brendan Sullivan, a Vice President of NTI, have served as Portfolio Managers of the Fund since its inception in October 2013 and June 2016, respectively.

Purchase and Sale of Fund Shares

FlexShares® STOXX® Global Broad Infrastructure Index Fund (cont.)

is willing to accept for shares of the Fund (ask) when buying or selling shares in the secondary market (“the bid-ask spread”). Recent information, including information about the Fund’s NAV, market price, premiums and discounts, and bid-ask spreads, is included on the Fund’s website at flexshares.com.

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

FlexShares® Global Quality Real Estate

Index Fund

Ticker: GQRE

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Northern Trust Global Quality Real Estate IndexSM (the “Underlying Index”).

Fees And Expenses Of The Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.45%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.46%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.45%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.45%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$46
3 Years	$147
5 Years	$257
10 Years	$578

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of companies that, in aggregate, maximize exposure to quality, value and momentum factors, within a universe of companies operating in the real estate sector. In order to be eligible for inclusion in the Underlying Index, a security must be a constituent of the Northern Trust Global Real Estate Index (the “Parent Index”), a float-adjusted market-capitalization weighted index of publicly-traded equity securities of U.S. and non-U.S. real estate investment trusts (REITs) and real estate operating companies. In addition, the Underlying Index utilizes the proprietary Northern Trust quality factor to identify companies that exhibit strength in profitability, management expertise and cash flow, while value and momentum factors are included to help provide long term capital appreciation and also mitigate risk.

To derive the Underlying Index, NTI, acting in its capacity as index provider (the “Index Provider”), ranks all constituents of the Parent Index using a Northern Trust proprietary blended multi-factor score. This score is designed to measure companies based on the quantitative assess

FlexShares® Global Quality Real Estate Index Fund (cont.)

ment of their respective (a) quality (i.e., a factor that seeks to identify companies that exhibit financial strength and stability relative to the Parent Index); (b) value (i.e., a factor reflecting the current worth a company relative to its own historical value, book value or valuation versus peers); and (c) momentum (i.e., a factor that reflects market sentiment and changes in security price over a given time period). The Index Provider then uses an optimization process to select and weight eligible securities in order to maximize the overall blended multi-factor score relative to the Parent Index. The optimization also includes industry group, region, country, style factor, single-security weight, liquidity and turnover constraints so that these index characteristics vary within acceptable bands relative to the Parent Index. A company must meet the following criteria to be eligible for inclusion in the Underlying Index: (a) a constituent of the Parent Index; and (b) it must be classified under the business sector of “Real Estate” by Refinitiv Business Classification or have registered as a real estate investment trust under its applicable local tax code. Companies classified under the business activities of Mortgage REITs and Real Estate Services (NEC) by Refinitiv Business Classification are excluded from the Underlying Index. The Underlying Index is reconstituted on a quarterly basis. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

As of December 31, 2023, the Underlying Index was comprised of 132 issues with market capitalizations ranging from $656.4 million to $122.4 billion.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. As of December 31, 2023, the Underlying Index was concentrated in the real estate sector. The components of the Underlying Index, and the degree to which these components represent certain industries or sectors, may change over time.

Principal Risks

FlexShares® Global Quality Real Estate Index Fund (cont.)

meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

Real Estate Securities Risk is the risk that the Fund is subject to the risks associated with investment in the real estate sector in addition to the general risk of the stock market. Investing in securities of real estate companies will make the Fund more susceptible to risks associated with the ownership of real estate and with the real estate industry in general, as well as risks that relate specifically to the way in which real estate companies are organized and operated. Real estate companies may have lower trading volumes and may be subject to more abrupt or erratic price movements than the overall securities markets. The value of real estate securities may underperform other sectors of the economy or broader equity markets. To the extent that the Fund concentrates its investments in the real estate sector, it may be subject to greater risk of loss than if it were diversified across different industry sectors.

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile and underperform other asset classes and the general securities markets.

Mid and Small Cap Stock Risk is the risk that stocks of mid-sized and smaller companies may be more volatile than stocks of larger, more established companies, and may

lack sufficient market liquidity. Mid-sized and small companies may have limited product lines or financial resources, may be dependent upon a particular niche of the market, or may be dependent upon a small or inexperienced management group. Securities of smaller companies may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally the smaller the company size, the greater the risk.

FlexShares® Global Quality Real Estate Index Fund (cont.)

Momentum Risk is the risk that securities that have had higher recent price performance compared to other securities may be more volatile than a broad cross-section of securities or that returns on securities that have previously exhibited price momentum are less than returns on other securities or the overall stock market. Momentum can turn quickly and cause significant variation from other types of investments.

Value Investing Risk is the risk that the Fund’s investment in companies whose securities are believed to be undervalued, relative to their underlying profitability, will not appreciate in value as anticipated.

Quality Factor Risk is the risk that the past performance of companies that have exhibited quality characteristics does not continue or the returns on securities issued by such companies may be less than returns from other styles of investing or the overall stock market. There may be periods when quality investing is out of favor and during which time the Fund's performance may suffer.

100

FlexShares® Global Quality Real Estate Index Fund (cont.)

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

101

FlexShares® Global Quality Real Estate Index Fund (cont.)

cial information, about such companies may be less available and reliable, which can impede the Fund’s ability to evaluate such companies. Securities law and the enforcement of systems of taxation in many emerging market countries may change quickly and unpredictably, and the ability to bring and enforce actions (including bankruptcy, confiscatory taxation, expropriation, nationalization of a company’s assets, restrictions on foreign ownership of local companies, restrictions on withdrawing assets from the country, protectionist measures and practices such as share blocking), or to obtain information needed to pursue or enforce such actions, may be limited. Investments in emerging market securities may be subject to additional transaction costs, delays in settlement procedures, unexpected market closures, and lack of timely information.

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

102

FlexShares® Global Quality Real Estate Index Fund (cont.)

how the Fund’s average annual returns compare with those of a broad measure of market performance, and (C) an additional index with characteristics relevant to the Fund. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated information on the Fund’s performance results can be obtained by visiting flexshares.com.

Calendar Year Total Returns

For the period shown in the bar chart above:

Best Quarter (3/31/2019): 15.40%

Worst Quarter (3/31/2020): -26.72%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Ten Year
Before Taxes	9.29%	3.15%	4.25%
After Taxes on Distributions	8.20%	2.11%	3.17%
After Taxes on Distributions and Sale of Shares	5.70%	2.09%	2.93%
FTSE EPRA/NAREIT Developed IndexSM*	9.68%	2.82%	3.58%
Northern Trust Global Quality Real Estate IndexSM*	9.16%	2.95%	4.12%

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Robert Anstine, a Senior Vice President of NTI, and Brendan Sullivan and Volter Bagriy, each a Vice President of NTI, have served as Portfolio Managers of the Fund since its inception in November 2013, June 2016 and March 2024, respectively.

Purchase and Sale of Fund Shares

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

103

FlexShares® Global Quality Real Estate Index Fund (cont.)

broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

104

FlexShares® Real Assets Allocation

Index Fund

Ticker: ASET

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Northern Trust Real Assets Allocation IndexSM (the “Underlying Index”).

Fees And Expenses Of The Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Under the Fund’s Investment Advisory Agreement, the Fund is responsible for the following other expenses: interest expenses, brokerage commissions and other trading expenses, fees and expenses of the independent trustees and their independent legal counsel, taxes and other extraordinary costs such as litigation and other expenses not incurred in the ordinary course of business. You will also incur usual and customary brokerage commissions and fees to financial intermediaries when buying or selling shares of the Fund in the secondary market, which are not reflected in the example that follows:

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)	0.49%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Acquired Fund Fees and Expenses	0.47%
Total Annual Fund Operating Expenses(2)	0.97%
Expense Reimbursement(3)	-0.48%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.49%

(1)

“Management Fees” have been restated to reflect current fees.

(2)

The “Total Annual Fund Operating Expenses” may not correlate to the ratio of expenses to average net assets as reported in the "Financial Highlights" section of the Prospectus, which reflects the operating expenses of the Fund and does include “Acquired Fund Fees and Expenses.”

(3)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses (“Acquired Fund Fees and Expenses”)) to the extent the “Total Annual Fund Operating Expenses” exceed 0.49%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. NTI also has contractually agreed until March 1, 2025 to waive a portion of its Management Fees and/or reimburse certain operating expenses in an amount equal to the Acquired Fund Fees and

Expenses attributable to the Fund’s investments in the Underlying Fund (as defined below). The Fund’s Board of Trustees may terminate the contractual agreements at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

The following Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 Year	$50
3 Years	$261
5 Years	$489
10 Years	$1,146

Principal Investment Strategies

The Fund is a fund of funds and seeks its investment objective by investing primarily in the shares of other FlexShares® ETFs (each an “Underlying Fund” and together, the “Underlying Funds”) that are eligible for inclusion in the Underlying Index and listed below, rather than in securities of individual companies. The Underlying Funds themselves seek investment results corresponding to their own respective underlying indexes. The Underlying Funds invest primarily in separate sets of securities representing or providing exposures to global “real assets.” Real assets are defined by NTI, acting in its capacity as index provider (the “Index Provider”), as physical or tangible assets. Examples of real assets include but are not limited to

105

FlexShares® Real Assets Allocation Index Fund (cont.)

commodities, precious metals, oil, and real estate. Each Underlying Fund has its own risk profile and will contribute differently to the overall risk profile of the Fund. Each of the Underlying Funds invests in equity securities that are traded in or are issued by companies domiciled in global developed or emerging markets (including the U.S.). Certain of the Underlying Funds may invest in publicly-traded units of master limited partnerships (“MLPs”) and real estate investment trusts (“REITs”).

The Underlying Index is designed to reflect the performance of an optimized allocation to the Underlying Funds that is intended to provide exposures to certain real assets and minimize overall volatility of investment in the Underlying Funds.

As of December 31, 2023, the Underlying Index was comprised of the following Underlying Funds, each of which invests primarily in equity securities: a 50.89% weight to FlexShares® STOXX® Global Broad Infrastructure Index Fund, a 31.29% weight to FlexShares® Morningstar Global Upstream Natural Resources Index Fund and a 17.83% weight to FlexShares® Global Quality Real Estate Index Fund. The Underlying Index was constituted and is rebalanced at least annually using a rules-based methodology. The Underlying Index may be rebalanced semi-annually if the volatility of investment in the Underlying Funds surpasses a minimum threshold. The weights of each Underlying Fund, and the degree to which each Underlying Fund represents exposure to certain real assets, may change over time as the Underlying Index and the underlying indexes of the Underlying Funds are reconstituted and/or rebalanced (which may be quarterly) and their component securities fluctuate in value. The Fund generally reconstitutes and/or rebalances its portfolio in accordance with the Underlying Index.

NTI generally intends to replicate the constituent securities of the Fund’s Underlying Index. “Replication” is an indexing strategy in which a fund invests in substantially all of the securities in its underlying index in approximately the same proportions as in the underlying index. NTI may use a “representative sampling” strategy in certain circumstances, such as when it may not be possible or practicable to fully implement a replication strategy. Representative sampling is investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index.

Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts and options on futures contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Underlying Index is created and sponsored by NTI. NTI also serves as the investment adviser to the Fund and the Underlying Funds. NTI, as the Index Provider, determines the composition and relative weightings of the securities in the Underlying Index and publishes information regarding the market value of the Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

From time to time the Fund may focus its investments (i.e., invest more than 15% of its total assets) in one or more particular countries or geographic regions.

Principal Risks

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), trading price, yield, total return and ability to meet its investment objective. Because the Fund will significantly invest in Underlying Funds, the risks described below are also applicable to the Underlying Funds, and to the extent that the Fund invests directly in securities and other instruments, the risks described below are also directly applicable to the Fund. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

106

FlexShares® Real Assets Allocation Index Fund (cont.)

industries. Compared to the broad market, an individual industry may be more strongly affected by changes in the economic climate, broad market shifts, moves in a particular dominant stock or regulatory changes.

•Natural Resources Sector Risk is the risk that the Fund is subject to the risks associated with investment in companies within the natural resources sector in addition to the general risk of the stock market. Companies within the natural resources sector can be significantly affected by events relating to U.S. and foreign political and economic developments and environmental and other government regulations, as well as other factors including, but not limited to: commodity price volatility, technological developments and natural or man-made disasters. Declines in the demand for, or prices of, natural resources generally would be expected to contribute to declines in the value of the Fund’s or Underlying Fund’s equity securities. Such declines may occur quickly and without warning and may negatively impact the value of the Fund and your investment.

•Infrastructure-Related Companies Risk is the risk that the Fund is subject to the risks associated with investment in infrastructure-related companies in addition to the general risk of the stock market. Risks associated with infrastructure-related companies include: (a) realized revenue volume may be significantly lower than projected and/or there will be cost overruns; (b) infrastructure project sponsors will alter their terms making a project no longer economical; (c) macroeconomic factors such as low gross domestic product (“GDP”) growth or high nominal interest rates will raise the average cost of infrastructure funding; (d) government regulation may affect rates charged to infrastructure customers; (e) government budgetary constraints will impact infrastructure projects; (f) special tariffs will be imposed; and (g) changes in tax laws, regulatory policies or accounting standards could be unfavorable. Other risks include environmental damage due to a company’s operations or an accident, a natural disaster, changes in market sentiment towards infrastructure and terrorist acts. Any of these events could cause the value of the Fund’s or Underlying Fund’s investments in infrastructure-related companies to decline.

liability to the same extent that a shareholder of a corporation would be. MLPs are also subject to risks related to potential conflicts of interest between the MLP and the MLP’s general partner and cash flow risks. MLPs that concentrate in a particular industry or a particular geographic region are subject to risks associated with such industry or region. MLPs may also be sensitive to changes in interest rates and during periods of interest rate volatility, limited capital markets access and/or low commodities pricing and may not provide attractive returns.

Real Estate Securities Risk is the risk that the Fund or an Underlying Fund is subject to the risks associated with investment in the real estate sector in addition to the general risk of the stock market. Investing in securities of real estate companies will make an Underlying Fund, and the Fund, more susceptible to risks associated with the ownership of real estate and with the real estate industry in general, as well as risks that relate specifically to the way in which real estate companies are organized and operated. Real estate companies may have lower trading volumes and may be subject to more abrupt or erratic price movements than the overall securities markets. The value of real estate securities may underperform other sectors of the economy or broader equity markets. To the extent that an Underlying Fund, and the Fund, concentrates its investments in the real estate sector, it may be subject to greater risk of loss than if it were diversified across different industry sectors.

107

FlexShares® Real Assets Allocation Index Fund (cont.)

engage in dilutive offerings or become more volatile than other securities. By investing in REITs through the Fund, a shareholder will bear expenses of the REITs in addition to expenses of the Fund. In addition, REITs could possibly fail to (i) qualify for favorable tax treatment under applicable tax law, or (ii) maintain their exemption from registration under the Investment Company Act of 1940.

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile and underperform other asset classes and the general securities markets.

Fund of Funds Risk is the risk that the Fund’s investment performance largely depends on the investment performance of the Underlying Funds in which it primarily invests. The Fund’s NAV will change with changes in the value of the Underlying Funds and other securities in which the Fund invests based on their market valuations. An investment of the Fund is subject to the risks associated with the Underlying Funds that comprise the Underlying Index. There is the risk that the Index Provider’s evaluations and assumptions regarding the asset classes represented by the Underlying Funds in the Underlying Index at any given time may be incorrect based on actual market conditions.

An investment in the Fund will entail more costs and expenses than direct investments in the Underlying Funds. The Fund will indirectly pay a proportional share of the expenses of the Underlying Funds in which it invests (including operating expenses and management fees), in addition to the fees and expenses it pays directly. As the Fund’s allocation to the Underlying Funds changes from time to time, or to the extent that the expense ratio of the Underlying Funds changes, the weighted average operating expenses borne by the Fund may increase or decrease.

Tax Risk is the risk that, because the Fund invests in the Underlying Funds, the Fund’s realized losses on sales of shares of the Underlying Funds may be indefinitely or permanently deferred as “wash sales.” Distributions of short-term capital gains by the Underlying Funds will be recognized as ordinary income by the Fund and would not be offset by the Fund’s capital loss carryforwards, if any. Capital loss carryforwards of the Underlying Funds, if any, would not offset net capital gains of the Fund. Each of these effects is caused by the Fund’s investment in the Underlying Funds and may result in distributions to Fund shareholders being of higher magnitudes and less likely to qualify for lower capital gain tax rates than if the Fund were to invest otherwise.

Model Risk is the risk that the asset allocation model used to calculate the Underlying Index will not achieve its intended results.

Value Investing Risk is the risk that an Underlying Fund’s investment in companies whose securities are believed to be undervalued, relative to their underlying profitability, will not appreciate in value as anticipated.

108

FlexShares® Real Assets Allocation Index Fund (cont.)

short periods of time. Currency hedging strategies, if used, are not always successful. For instance, forward foreign currency exchange contracts, if used by the Fund, could reduce performance if there are unanticipated changes in currency exchange rates.

rities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment could have a significant impact on the Fund and its investments and could result in the Fund’s shares trading at increased premiums or discounts to the Fund’s NAV. During periods of market disruption or other abnormal market conditions, the Fund’s exposure to the risks described elsewhere in this summary will likely increase.

109

FlexShares® Real Assets Allocation Index Fund (cont.)

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

Market Trading Risk is the risk that the Fund and the Underlying Funds face because their shares are listed on a securities exchange, including the potential lack of an active market for Fund shares, losses from trading in secondary markets, periods of high volatility and disruption in the creation/redemption process of the Fund or Underlying Fund. ANY OF THESE FACTORS MAY LEAD TO THE FUND’S SHARES TRADING AT A PREMIUM OR DISCOUNT TO NAV.

as intended; the possible inability of the Fund to sell or close out a futures contract at the desired time or price; losses due to unanticipated market movements, which potentially are unlimited; and the possible inability of NTI to correctly predict the direction of securities’ prices, interest rates, currency exchange rates and other economic factors, which may make the Fund’s returns more volatile or increase the risk of loss.

110

FlexShares® Real Assets Allocation Index Fund (cont.)

out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Fund. During periods when inflation rates are high or rising, or during periods of low interest rates, the Fund may be subject to a greater risk of rising interest rates.

Valuation Risk is the risk that the sale price the Fund or an Underlying Fund could receive for a portfolio security may differ from the Fund’s or the Underlying Fund’s valuation of the security, particularly for securities that trade in low volume or volatile markets or that are valued using a fair value methodology. In addition, the value of the securities in the Fund’s or an Underlying Fund’s portfolio may change on days when shareholders will not be able to purchase or sell the Fund’s shares.

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

additional index with characteristics relevant to the Fund. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated information on the Fund’s performance results can be obtained by visiting flexshares.com.

Calendar Year Total Returns

For the periods in the bar chart above:

Best Quarter (3/31/2019): 14.27%

Worst Quarter (3/31/2020): -23.50%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Since Inception of Fund	Inception Date of Fund
Before Taxes	5.51%	6.65%	5.53%	11/23/2015
After Taxes on Distributions	4.71%	5.84%	4.66%	—
After Taxes on Distributions and Sale of Shares	3.69%	5.04%	4.14%	—
MSCI ACWI Index*	22.20%	11.74%	9.33%	—
Northern Trust Real Assets Allocation IndexSM*	5.59%	6.78%	5.65%	—

Reflects no deduction for fees, expenses or taxes.

111

FlexShares® Real Assets Allocation Index Fund (cont.)

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Robert Anstine, a Senior Vice President of NTI, and Brendan Sullivan, a Vice President of NTI, have served as Portfolio Managers of the Fund since its inception in November 2015 and June 2016, respectively.

Purchase and Sale of Fund Shares

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

112

FlexShares® Quality Dividend Index Fund

Ticker: QDF

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Northern Trust Quality Dividend IndexSM (the “Underlying Index”).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.37%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.38%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.37%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.37%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$38
3 Years	$121
5 Years	$212
10 Years	$479

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of companies that, in aggregate, provide exposure to a high-quality income-oriented universe of long-only U.S. equity securities, with an emphasis on long-term capital growth and a targeted overall beta that is similar to that of the Northern Trust 1250 Index (the “Parent Index”), a float-adjusted market-capitalization weighted index of U.S. domiciled large- and mid-capitalization companies. Beta represents the market sensitivity, relative to a given market index and time period, and is one measure of volatility.

To derive the Underlying Index, NTI, acting in its capacity as the index provider (the “Index Provider”), begins with all securities in the Parent Index and then removes those securities that rank in the lowest quintile of quality based on a proprietary scoring model, as well as those which do not pay a dividend. The core components of the proprietary quality scoring model are based on quantitative ranking of various metrics obtained from company filings. These scores have three components: (i) management efficiency (e.g., corporate finance activities); (ii) profitability

113

FlexShares® Quality Dividend Index Fund (cont.)

(e.g., reliability and sustainability of financial performance); and (iii) cash flow (e.g., cash flow generation). The Index Provider then uses an optimization process to select and weight eligible securities in order to (a) maximize the overall quality score relative to the Parent Index; (b) attain an aggregate dividend yield in excess of the Parent Index; and (c) achieve the desired beta target. The optimization process also includes sector, industry group, single-security weight and turnover constraints to assist in reducing the Underlying Index’s overall active risk exposure to any one single factor. As of December 31, 2023, there were 130 issues in the Underlying Index. The Underlying Index is reconstituted quarterly. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

NTI uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” its Underlying Index and does not seek temporary defensive positions when markets decline or appear overvalued.

Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts and options on futures contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. As of December 31, 2023, the Underlying Index was concentrated in the Information Technology sector. The components of the Underlying Index, and the degree to which these components represent certain industries or sectors, may change over time.

Principal Risks

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile and underperform other asset classes and the general securities markets.

Concentration Risk is the risk that, if the Fund is concentrated in a particular industry or group of industries, the Fund is likely to present more risks than a fund that is

114

FlexShares® Quality Dividend Index Fund (cont.)

•Information Technology Sector Risk is the risk that securities of technology companies may be subject to greater price volatility than securities of companies in other sectors. These securities may fall in and out of favor with investors rapidly, which may cause sudden selling and dramatically lower market prices. Technology securities also may be affected adversely by changes in technology, consumer and business purchasing patterns, government regulation and/or obsolete products or services.

Dividend Risk is the risk that an issuer of stock held by the Fund may choose not to declare a dividend or the dividend rate might not remain at current levels. Dividend paying stocks might not experience the same level of earnings growth or capital appreciation as non-dividend paying stocks. The Fund’s performance during a broad market advance could suffer because dividend paying stocks may not experience the same capital appreciation as non-dividend paying stocks.

Volatility Risk is the risk that the actual level of volatility experienced by the Fund may be greater or lower than the targeted overall volatility of the Underlying Index. Although the Underlying Index is designed to have a targeted overall volatility that is similar to that of the Parent Index, there is no guarantee that it will have the targeted overall volatility. The Fund will continue to seek to track the Underlying Index even if the Underlying Index does not have the targeted overall volatility. There is also the risk that the Fund may experience volatility greater or lower than that of the Underlying Index as a result of tracking error. A portfolio of securities with greater volatility is generally considered to have a higher risk profile than a portfolio with lower volatility.

115

FlexShares® Quality Dividend Index Fund (cont.)

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

Trading in Fund shares may be halted due to market conditions or for reasons that, in the view of its listing exchange, make trading in the shares inadvisable. The market prices

of Fund shares will generally fluctuate in accordance with changes in its NAV, changes in the relative supply of, and demand for, Fund shares, and changes in the liquidity, or the perceived liquidity, of the Fund’s holdings.

Securities Lending Risk is the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. The

116

FlexShares® Quality Dividend Index Fund (cont.)

Fund could also lose money in the event of a decline in the value of collateral provided for loaned securities or a decline in the value of any investments made with cash collateral.

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

Calendar Year Total Returns

For the periods in the bar chart above:

Best Quarter (6/30/2020): 18.51%

Worst Quarter (3/31/2020): -25.18%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Ten Year
Before Taxes	19.63%	11.94%	9.44%
After Taxes on Distributions	18.86%	11.19%	8.62%
After Taxes on Distributions and Sale of Shares	11.92%	9.33%	7.46%
Russell 1000® Index*	26.53%	15.54%	11.81%
Northern Trust Quality Dividend IndexSM*	20.09%	12.47%	9.97%

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Robert Anstine, a Senior Vice President of NTI, and Brendan Sullivan and Steven Santiccoli, each a Vice President of NTI, have served as Portfolio Managers of the Fund since October 2013, June 2016 and March 2021, respectively.

Purchase and Sale of Fund Shares

117

FlexShares® Quality Dividend Index Fund (cont.)

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

118

FlexShares® Quality Dividend Defensive

Index Fund

Ticker: QDEF

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Northern Trust Quality Dividend Defensive IndexSM (the “Underlying Index”).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.37%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.38%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.37%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.37%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$38
3 Years	$121
5 Years	$212
10 Years	$479

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of companies that, in aggregate, provide exposure to a high quality income-oriented universe of long-only U.S. equity securities, with an emphasis on long-term capital growth and a targeted overall beta that is generally between 0.5 to 1.0 times that of the Northern Trust 1250 Index (the “Parent Index”), a float-adjusted market-capitalization weighted index of U.S. domiciled large- and mid-capitalization companies. Beta represents the market sensitivity, relative to a given market index and time period, and is one measure of volatility.

119

FlexShares® Quality Dividend Defensive Index Fund (cont.)

(e.g., reliability and sustainability of financial performance); and (iii) cash flow (e.g., cash flow generation). The Index Provider then uses an optimization process to select and weight eligible securities in order to (a) maximize the overall quality score relative to the Parent Index, (b) attain an aggregate dividend yield in excess of the Parent Index and (c) achieve the desired beta target. The optimization process also includes sector, industry group, single-security weight and turnover constraints to assist in reducing the Underlying Index’s overall active risk exposure to any one single factor. As of December 31, 2023, there were 128 issues in the Underlying Index. The Underlying Index is reconstituted quarterly. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts and options on futures contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. As of December 31, 2023, the Underlying Index was concentrated in the Information Technology sector. The components of the Underlying Index, and the degree to which these components represent certain industries or sectors, may change over time.

Principal Risks

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile and underperform other asset classes and the general securities markets.

Concentration Risk is the risk that, if the Fund is concentrated in a particular industry or group of industries, the Fund is likely to present more risks than a fund that is

120

FlexShares® Quality Dividend Defensive Index Fund (cont.)

Volatility Risk is the risk that the actual level of volatility experienced by the Fund may be greater or lower than the targeted overall volatility of the Underlying Index. Although the Underlying Index is designed to have a targeted overall volatility that is lower than that of the Parent Index, there is no guarantee that it will have the targeted overall volatility. The Fund will continue to seek to track the Underlying Index even if the Underlying Index does not have the targeted overall volatility. There is also the risk that the Fund may experience volatility greater or lower than that of the Underlying Index as a result of tracking error. A portfolio of securities with greater volatility is generally considered to have a higher risk profile than a portfolio with lower volatility.

121

FlexShares® Quality Dividend Defensive Index Fund (cont.)

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

Trading in Fund shares may be halted due to market conditions or for reasons that, in the view of its listing exchange, make trading in the shares inadvisable. The market prices

Securities Lending Risk is the risk that the Fund may lose money because the borrower of the loaned securities fails to return the securities in a timely manner or at all. The

122

FlexShares® Quality Dividend Defensive Index Fund (cont.)

Fund could also lose money in the event of a decline in the value of collateral provided for loaned securities or a decline in the value of any investments made with cash collateral.

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

Calendar Year Total Returns

For the periods in the bar chart above:

Best Quarter (6/30/2020): 15.95%

Worst Quarter (3/31/2020): -23.37%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Ten Year
Before Taxes	17.42%	11.23%	9.58%
After Taxes on Distributions	16.71%	10.53%	8.72%
After Taxes on Distributions and Sale of Shares	10.67%	8.81%	7.59%
Russell 1000® Index*	26.53%	15.54%	11.81%
Northern Trust Quality Dividend Defensive IndexSM*	17.80%	11.73%	10.15%

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Robert Anstine, a Senior Vice President of NTI, and Brendan Sullivan and Yair Walny, each a Vice President of NTI, have served as Portfolio Managers of the Fund since October 2013, June 2016 and March 2024, respectively.

Purchase and Sale of Fund Shares

123

FlexShares® Quality Dividend Defensive Index Fund (cont.)

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

124

FlexShares® International Quality

Dividend Index Fund

Ticker: IQDF

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Northern Trust International Quality Dividend IndexSM (the “Underlying Index”).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.47%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.02%
Total Annual Fund Operating Expenses	0.49%
Expense Reimbursement(1)	-0.02%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.47%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.47%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$48
3 Years	$155
5 Years	$272
10 Years	$614

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of companies that, in aggregate, provide exposure to a high-quality income-oriented universe of long-only international securities issued by non-U.S.- based companies, with an emphasis on long-term capital growth and a targeted overall beta that is similar to that of the Northern Trust International Large Cap Index (the “Parent Index”), a float-adjusted market-capitalization weighted index of non-US domiciled large- and mid-capitalization companies. Beta represents the market sensitivity, relative to a given market index and time period, and is one measure of volatility.

To derive the Underlying Index, NTI, acting in its capacity as the index provider (the “Index Provider”), begins with all securities in the Parent Index that have an average daily traded value of at least $125,000 in the 90 days prior to a reconstitution, and then removes those securities that rank in the lowest quintile of quality based on a proprietary scoring model, as well as those which do not pay a dividend. The core components of the proprietary quality scoring model are based on quantitative ranking of various

125

FlexShares® International Quality Dividend Index Fund (cont.)

metrics obtained from company filings. These scores have three components: (i) management efficiency (e.g., corporate finance activities); (ii) profitability (e.g., reliability and sustainability of financial performance); and (iii) cash flow (e.g., cash flow generation). The Index Provider then uses an optimization process to select and weight eligible securities in order to (a) maximize the overall quality score relative to the Parent Index; (b) attain an aggregate dividend yield in excess of the Parent Index; and (c) achieve the desired beta target. The optimization process also includes sector, industry group, region, country, single-security weight and turnover constraints to assist in reducing the Underlying Index’s overall active risk exposure to any one single factor. As of December 31, 2023, there were 190 issues in the Underlying Index. The Underlying Index is reconstituted quarterly. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index and in American Depositary Receipts (“ADRs”) and Global Depositary Receipts (“GDRs”) (collectively “Depositary Receipts”) based on the securities in the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts, options on futures contracts and foreign currency contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Principal Risks

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile and underperform other asset classes and the general securities markets.

126

FlexShares® International Quality Dividend Index Fund (cont.)

panies may trade less frequently and in lower volume than the securities of larger companies, which could lead to higher transaction costs. Generally the smaller the company size, the greater the risk.

generally may be subject to less stringent regulatory, disclosure, financial reporting, accounting, auditing and recordkeeping standards than companies in more developed countries. As a result, information, including financial information, about such companies may be less available and reliable, which can impede the Fund’s ability to evaluate such companies. Securities law and the enforcement of systems of taxation in many emerging market countries may change quickly and unpredictably, and the ability to bring and enforce actions (including bankruptcy, confiscatory taxation, expropriation, nationalization of a company’s assets, restrictions on foreign ownership of local companies, restrictions on withdrawing assets from the country, protectionist measures and practices such as share blocking), or to obtain information needed to pursue or enforce such actions, may be limited. Investments in emerging market securities may be subject to additional transaction costs, delays in settlement procedures, unexpected market closures, and lack of timely information.

127

FlexShares® International Quality Dividend Index Fund (cont.)

Sampling Risk is the risk that the Fund’s use of a representative sampling approach may result in increased tracking error because the securities selected for the Fund in the

128

FlexShares® International Quality Dividend Index Fund (cont.)

aggregate may vary from the investment profile of the Underlying Index. Additionally, the use of a representative sampling approach may result in the Fund holding a smaller number of securities than the Underlying Index, and, as a result, an adverse development to an issuer of securities that the Fund holds could result in a greater decline in NAV than would be the case if the Fund held all of the securities in the Underlying Index.

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

Trading in Fund shares may be halted due to market conditions or for reasons that, in the view of its listing exchange, make trading in the shares inadvisable. The market prices

129

FlexShares® International Quality Dividend Index Fund (cont.)

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

Calendar Year Total Returns

For the period shown in the bar chart above:

Best Quarter (12/31/2020): 18.20%

Worst Quarter (3/31/2020): -26.07%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Ten Year
Before Taxes	19.61%	7.11%	3.11%
After Taxes on Distributions	17.72%	5.85%	2.02%
After Taxes on Distributions and Sale of Shares	12.58%	5.40%	2.28%
MSCI ACWI ex USA Index*	15.62%	7.09%	3.83%
Northern Trust International Quality Dividend IndexSM*	20.72%	7.47%	3.48%

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Robert Anstine, a Senior Vice President of NTI, and Brendan Sullivan and Alan Aung, each a Vice President of NTI, have served as Portfolio Managers of the Fund since October 2013, June 2016 and March 2024, respectively.

Purchase and Sale of Fund Shares

130

FlexShares® International Quality Dividend Index Fund (cont.)

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

131

FlexShares® International Quality

Dividend Defensive Index Fund

Ticker: IQDE

Investment Objective

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.47%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.48%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.47%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.47%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$48
3 Years	$153
5 Years	$268
10 Years	$603

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of companies that, in aggregate, provide exposure to a high-quality income-oriented universe of long-only international securities issued by non-U.S.-based companies, with an emphasis on long-term capital growth and a targeted overall beta that is generally between 0.5 to 1.0 times that of the Northern Trust International Large Cap Index (the “Parent Index”), a float-adjusted market-capitalization weighted index of non-US domiciled large- and mid-capitalization companies. Beta represents the market sensitivity, relative to a given market index and time period, and is one measure of volatility.

132

FlexShares® International Quality Dividend Defensive Index Fund (cont.)

metrics obtained from company filings. These scores have three components: (i) management efficiency (e.g., corporate finance activities); (ii) profitability (e.g., reliability and sustainability of financial performance); and (iii) cash flow (e.g., cash flow generation). The Index Provider then uses an optimization process to select and weight eligible securities in order to (a) maximize the overall quality score relative to the Parent Index, (b) attain an aggregate dividend yield in excess of the Parent Index and (c) achieve the desired beta target. The optimization process also includes sector, industry group, region, country, single-security weight and turnover constraints to assist in reducing the Underlying Index’s overall active risk exposure to any one single factor. As of December 31, 2023, there were 196 issues in the Underlying Index. The Underlying Index is reconstituted quarterly. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index and in American Depositary Receipts (“ADRs”) and Global Depositary Receipts (“GDRs”) (collectively “Depositary Receipts”) based on the securities in the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts, options on futures contracts and foreign currency contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Principal Risks

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile and underperform other asset classes and the general securities markets.

133

FlexShares® International Quality Dividend Defensive Index Fund (cont.)

134

FlexShares® International Quality Dividend Defensive Index Fund (cont.)

Volatility Risk is the risk that the actual level of volatility experienced by the Fund may be greater or lower than the targeted overall volatility of the Underlying Index. Although the Underlying Index is designed to have a targeted overall volatility that is lower than that of the Parent Index, there is no guarantee that it will have the targeted overall volatility. The Fund will continue to seek to track the Underlying Index even if the Underlying Index does not have the targeted overall volatility. There is also the risk that the Fund may experience volatility greater or lower than that of the Underlying Index as a result of tracking error. A portfolio of securities with greater volatility is generally considered to have a higher risk profile than a portfolio with lower volatility.

Sampling Risk is the risk that the Fund’s use of a representative sampling approach may result in increased tracking error because the securities selected for the Fund in the

135

FlexShares® International Quality Dividend Defensive Index Fund (cont.)

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

Trading in Fund shares may be halted due to market conditions or for reasons that, in the view of its listing exchange, make trading in the shares inadvisable. The market prices

136

FlexShares® International Quality Dividend Defensive Index Fund (cont.)

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

Calendar Year Total Returns

For the period shown in the bar chart above:

Best Quarter (12/31/2020): 17.18%

Worst Quarter (3/31/2020): -24.91%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Ten Year
Before Taxes	14.82%	5.54%	2.26%
After Taxes on Distributions	13.28%	4.42%	1.21%
After Taxes on Distributions and Sale of Shares	9.73%	4.26%	1.66%
MSCI ACWI ex USA Index*	15.62%	7.09%	3.83%
Northern Trust International Quality Dividend Defensive IndexSM*	16.04%	5.97%	2.78%

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Robert Anstine, a Senior Vice President of NTI, and Brendan Sullivan and Steven Santiccoli, each a Vice President of NTI, have served as Portfolio Managers of the Fund since October 2013, June 2016 and March 2024, respectively.

Purchase and Sale of Fund Shares

137

FlexShares® International Quality Dividend Defensive Index Fund (cont.)

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

138

FlexShares® International Quality

Dividend Dynamic Index Fund

Ticker: IQDY

Investment Objective

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.47%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.48%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.47%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.47%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$48
3 Years	$153
5 Years	$268
10 Years	$603

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of companies that, in aggregate, provide exposure to a high-quality income-oriented universe of long-only international securities issued by non-U.S.-based companies, with an emphasis on long-term capital growth and a targeted overall beta that is generally between 1.0 to 1.5 times that of the Northern Trust International Large Cap Index (the “Parent Index”), a float-adjusted market-capitalization weighted index of non-US domiciled large- and mid-capitalization companies. Beta represents the market sensitivity, relative to a given market index and time period, and is one measure of volatility.

139

FlexShares® International Quality Dividend Dynamic Index Fund (cont.)

metrics obtained from company filings. These scores have three components: (i) management efficiency (e.g., corporate finance activities); (ii) profitability (e.g., reliability and sustainability of financial performance); and (iii) cash flow (e.g., cash flow generation). The Index Provider then uses an optimization process to select and weight eligible securities in order to (a) maximize the overall quality score relative to the Parent Index, (b) attain an aggregate dividend yield in excess of the Parent Index and (c) achieve the desired beta target. The optimization process also includes sector, industry group, region, country, single-security weight and turnover constraints to assist in reducing the Underlying Index’s overall active risk exposure to any one single factor. As of December 31, 2023, there were 151 issues in the Underlying Index. The Underlying Index is reconstituted quarterly. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index and in American Depositary Receipts (“ADRs”) and Global Depositary Receipts (“GDRs”) (collectively “Depositary Receipts”) based on the securities in the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts, options on futures contracts and foreign currency contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Principal Risks

Equity Securities Risk is the risk that the values of the equity securities owned by the Fund may be more volatile and underperform other asset classes and the general securities markets.

140

FlexShares® International Quality Dividend Dynamic Index Fund (cont.)

141

FlexShares® International Quality Dividend Dynamic Index Fund (cont.)

Volatility Risk is the risk that the actual level of volatility experienced by the Fund may be greater or lower than the targeted overall volatility of the Underlying Index. Although the Underlying Index is designed to have a targeted overall volatility that is greater than that of the Parent Index, there is no guarantee that it will have the targeted overall volatility. The Fund will continue to seek to track the Underlying Index even if the Underlying Index does not have the targeted overall volatility. There is also the risk that the Fund may experience volatility greater or lower than that of the Underlying Index as a result of tracking error. A portfolio of securities with greater volatility is generally considered to have a higher risk profile than a portfolio with lower volatility.

Sampling Risk is the risk that the Fund’s use of a representative sampling approach may result in increased tracking error because the securities selected for the Fund in the

142

FlexShares® International Quality Dividend Dynamic Index Fund (cont.)

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

Trading in Fund shares may be halted due to market conditions or for reasons that, in the view of its listing exchange, make trading in the shares inadvisable. The market prices

143

FlexShares® International Quality Dividend Dynamic Index Fund (cont.)

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

Calendar Year Total Returns

For the period shown in the bar chart above:

Best Quarter (12/31/2020): 22.83%

Worst Quarter (3/31/2020): -26.51%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Ten Year
Before Taxes	23.23%	10.06%	4.65%
After Taxes on Distributions	21.19%	8.84%	3.63%
After Taxes on Distributions and Sale of Shares	14.84%	7.81%	3.53%
MSCI ACWI ex USA Index*	15.62%	7.09%	3.83%
Northern Trust International Quality Dividend Dynamic IndexSM*	24.52%	10.53%	5.14%

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI., a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Robert Anstine, a Senior Vice President of NTI, and Brendan Sullivan and Steven Santiccoli, each a Vice President of NTI, have served as Portfolio Managers of the Fund since October 2013, June 2016 and March 2021, respectively.

Purchase and Sale of Fund Shares

144

FlexShares® International Quality Dividend Dynamic Index Fund (cont.)

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

145

FlexShares® iBoxx 3-Year Target Duration

TIPS Index Fund

Ticker: TDTT

Investment Objective

The Fund seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of the iBoxx 3-Year Target Duration TIPS Index (the “Underlying Index”).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.18%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.19%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.18%

(1)

Example

1 Year	$18
3 Years	$60
5 Years	$106
10 Years	$242

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of inflation protected public obligations of the U.S. Treasury, commonly known as “TIPS,” with a targeted average modified adjusted duration, as defined by S&P Dow Jones Indices LLC as the Index Provider (“Index Provider” or “SPDJI”), of approximately three years. The Underlying Index includes publicly issued TIPS that have maturity dates of at least one year but not more than ten years from an index rebalancing date. TIPS are securities issued by the U.S. Treasury that are designed to provide inflation protection to investors. TIPS’ principal and interest payments are linked to an official inflation measure (as measured by the Consumer Price Index for All Urban Consumers, or CPI-U) and the payments are supported by the full faith and credit of the United States. As of December 31, 2023, there were 27 TIPS in the Underlying Index. The components of the Underlying Index are weighted by the Index Provider to achieve the targeted average modified adjusted duration and its composition is rebalanced monthly. The Fund generally rebalances its portfolio in accordance with the Underlying Index.

146

FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund (cont.)

NTI uses a “passive” or indexing approach to try to achieve the Fund’s investment objective. Unlike many investment companies, the Fund does not try to “beat” the index it tracks and does not seek temporary defensive positions when markets decline or appear overvalued. NTI generally intends to replicate the constituent securities of the Fund’s Underlying Index. “Replication” is an indexing strategy in which a fund invests in substantially all of the securities in its underlying index in approximately the same proportions as in the underlying index. NTI may use a “representative sampling” strategy in certain circumstances, such as when it may not be possible or practicable to fully implement a replication strategy. Representative sampling is investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index. When the Fund uses representative sampling, it may or may not hold all of the securities that are included in the Underlying Index.

Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts and options on futures contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Principal Risks

Inflation Protected Security Risk is the risk that the value of inflation protected securities, such as TIPS, generally will fluctuate in response to changes in real interest rates, generally decreasing when real interest rates rise and increasing when real interest rates fall. In addition, interest payments on inflation-protected securities will generally vary up or down along with the rate of inflation. Real interest rates are generally measured as a nominal interest less an inflation rate. As such, investors should be aware that an investment in TIPS over a particular timeframe may decrease in value even in an inflationary environment. There can be no assurance that the inflation index used will accurately measure the real rate of inflation in the prices of goods and services. Because of their inflation adjustment feature, inflation-protected bonds typically have lower yields than conventional fixed-rate bonds. In addition, the market for inflation-indexed securities may be less developed or liquid, and more volatile, than certain other securities markets. In addition, positive adjustments to principal generally will result in taxable income to the Fund at the time of such adjustments (which generally would be distributed by the Fund as part of its taxable dividends), even though the principal amount is not paid until maturity.

Income Risk is the risk that the Fund's income may decline due to a decline in inflation (or deflation) or due to changes in inflation expectations.

147

FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund (cont.)

may have unpredictable effects on the markets and the Fund’s investments, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Fund, and may detract from Fund performance. A low or negative interest rate environment could cause the Fund’s earnings to fall below the Fund’s expense ratio, resulting in a negative yield and a decline in the Fund’s share price. An increase in interest rates may cause investors to move out of fixed incomes securities on a large scale, which could adversely affect the price of fixed income securities, lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments.

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

148

FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund (cont.)

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund by showing (A) changes in the Fund’s performance from year to year and (B) how the Fund’s average annual returns compare with those of a broad measure of market performance. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated information on the Fund’s performance results can be obtained by visiting flexshares.com.

Calendar Year Total Returns

For the periods shown in the bar chart above:

Best Quarter (6/30/2020): 3.31%

Worst Quarter (9/30/2022): -3.28%

149

FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund (cont.)

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Ten Year
Before Taxes	4.54%	3.51%	1.92%
After Taxes on Distributions	2.90%	2.01%	0.93%
After Taxes on Distributions and Sale of Shares	2.67%	2.06%	1.05%
iBoxx 3-Year Target Duration TIPS Index*	4.64%	3.69%	2.07%

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. David M. Alongi, a Senior Vice President of NTI, and Michael R. Chico, a Vice President of NTI, have served as Portfolio Managers of the Fund since March 2023 and its inception in September 2011, respectively.

Purchase and Sale of Fund Shares

chase shares of the Fund (bid) and the lowest price a seller is willing to accept for shares of the Fund (ask) when buying or selling shares in the secondary market (“the bid-ask spread”). Recent information, including information about the Fund’s NAV, market price, premiums and discounts, and bid-ask spreads, is included on the Fund’s website at flexshares.com.

Tax Information

The Fund’s distributions are generally taxable to you as ordinary income, capital gains, or a combination of the two, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

Payments to Brokers-Dealers and Other Financial Intermediaries

150

FlexShares® iBoxx 5-Year Target Duration

TIPS Index Fund

Ticker: TDTF

Investment Objective

The Fund seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of the iBoxx 5-Year Target Duration TIPS Index (the “Underlying Index”).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.18%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.19%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.18%

(1)

Example

1 Year	$18
3 Years	$60
5 Years	$106
10 Years	$242

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of inflation protected public obligations of the U.S. Treasury, commonly known as “TIPS,” with a targeted average modified adjusted duration, as defined by S&P Dow Jones Indices LLC as the Index Provider (“Index Provider” or “SPDJI”), of approximately five years. The Underlying Index includes publicly issued TIPS that have maturity dates of at least three years but not more than twenty years from an index rebalancing date. TIPS are securities issued by the U.S. Treasury that are designed to provide inflation protection to investors. TIPS’ principal and interest payments are linked to an official inflation measure (as measured by the Consumer Price Index for All Urban Consumers, or CPI-U) and the payments are supported by the full faith and credit of the United States. As of December 31, 2023, there were 25 TIPS in the Underlying Index. The components of the Underlying Index are weighted by the Index Provider to achieve the targeted average modified adjusted duration and its composition is rebalanced monthly. The Fund generally rebalances its portfolio in accordance with the Underlying Index.

151

FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund (cont.)

Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts and options on futures contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Principal Risks

Income Risk is the risk that the Fund's income may decline due to a decline in inflation (or deflation) or due to changes in inflation expectations.

152

FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund (cont.)

Market Risk is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failure, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment could have a significant impact on the Fund and its investments and could result in the Fund’s shares trading at increased premiums or discounts to the Fund’s NAV. During periods of market disruption or other abnormal market conditions, the Fund’s exposure to the risks described elsewhere in this summary will likely increase.

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

153

FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund (cont.)

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund by showing (A) changes in the Fund’s performance from year to year and (B) how the Fund’s average annual returns compare with those of a broad measure of market performance. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated information on the Fund’s performance results can be obtained by visiting flexshares.com.

Calendar Year Total Returns

154

FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund (cont.)

For the periods shown in the bar chart above:

Best Quarter (12/31/2023): 4.53%

Worst Quarter (6/30/2022): -4.68%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Ten Year
Before Taxes	4.19%	3.39%	2.14%
After Taxes on Distributions	2.52%	1.85%	1.07%
After Taxes on Distributions and Sale of Shares	2.46%	1.97%	1.19%
iBoxx 5-Year Target Duration TIPS Index*	4.33%	3.60%	2.30%

Reflects no deduction for fees, expenses or taxes.

Management

Purchase and Sale of Fund Shares

prices rather than NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). An investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase shares of the Fund (bid) and the lowest price a seller is willing to accept for shares of the Fund (ask) when buying or selling shares in the secondary market (“the bid-ask spread”). Recent information, including information about the Fund’s NAV, market price, premiums and discounts, and bid-ask spreads, is included on the Fund’s website at flexshares.com.

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

155

FlexShares® Disciplined Duration

MBS Index Fund

Ticker: MBSD

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of The ICE BofA® Constrained Duration US Mortgage Backed Securities IndexSM (the “Underlying Index”).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.20%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.21%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.20%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.20%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same (taking into account the expense reimbursement arrangement for one year). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 Year	$20
3 Years	$67
5 Years	$117
10 Years	$267

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of investment-grade US agency residential mortgage backed pass-through securities. The term “US agency mortgage-backed pass-through security” (“MBS”) refers to a category of pass-through securities backed by pools of mortgages and issued by one of the following US government agencies: the Federal National Mortgage Association (FNMA or Fannie Mae), the Federal Home Loan Mortgage Corporation (FHLMC or Freddie Mac) or the Government National Mortgage Association (GNMA or Ginnie Mae) (each a “US Agency”). The Underlying Index is formed by grouping the universe of individual fixed-rate mortgage-backed securities pools into generic aggregates according to the following parameters: (i) agency; (ii) mortgage program; (iii) pass-through coupon; and (iv) origination year. These aggregates are then assessed based on certain criteria, as determined by ICE Data Indices, LLC as the Index Provider (“Index Provider” or “ICE”), to determine eligibility for inclusion in the Underlying Index. MBS that are eligible for inclusion in

156

FlexShares® Disciplined Duration MBS Index Fund (cont.)

the Underlying Index (a) have been issued by a US Agency, (b) have a weighted average remaining time to final stated maturity of at least one year, (c) have at least $5 billion or more of outstanding face value in the coupon for a given agency program, (d) have at least $1 billion or more of outstanding face value at the time of inclusion in the Underlying Index and at least $250 million to remain in the Index and (e) are characterized by one or more of the following fixed-rate mortgage programs: 30-year, 20-year, and 15-year maturities. The Underlying Index constituents are capitalization-weighted, based on their outstanding face value times price plus accrued interest, adjusted by the Index Provider, to achieve an effective duration that is generally between 3.25 and 4.25 years. Balloon, mobile home, graduated payment and quarter coupon fixed rate mortgages are excluded from the Underlying Index, as are all collateralized mortgage obligations.

The Fund generally will invest under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index and in “TBA Transactions” (defined below) that represent securities in the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts and options on futures contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index. Most transactions in mortgage pass-through securities occur through standard

ized contracts for future delivery in which the exact mortgage pools to be delivered are not specified until a few days prior to settlement, referred to as a “to-be announced transaction” or “TBA Transaction.” In a TBA Transaction, the buyer and seller agree upon general trade parameters such as agency, coupon rate, settlement date, par amount and price. The actual pools delivered generally are determined two days prior to the settlement date. The Fund expects to enter into such contracts on a regular basis, and pending settlement of such contracts, the Fund will invest its assets in liquid, short-term instruments, which may include shares of money market funds advised by NTI or its affiliates. The Fund will assume its pro rata share of the fees and expenses of any money market fund, in which it may invest, in addition to the Fund’s own fees and expenses.

The Underlying Index is sponsored by the Index Provider. The Index Provider is not affiliated with the Fund or NTI. The Index Provider determines the composition and relative weightings of the securities in the Underlying Index in accordance with a published methodology and disseminates information regarding the market value of the Underlying Index. The Underlying Index is rebalanced on the last calendar day of each month. The Fund generally rebalances its portfolio in accordance with the Underlying Index. As of December 31, 2023, there were 119 MBS in the Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities) are not considered to be issued by members of any industry. As of December 31, 2023, the Underlying Index was concentrated in the financial sector. The components of the Underlying Index, and the degree to which these components represent certain industries or sectors, may change over time.

Principal Risks

As with any investment, you could lose all or part of your investment in the Fund, and the Fund’s performance could

157

FlexShares® Disciplined Duration MBS Index Fund (cont.)

trail that of other investments. The Fund is subject to certain risks, including the principal risks noted below, any of which may adversely affect the Fund’s net asset value (“NAV”), trading price, yield, total return and ability to meet its investment objective. Each risk noted below is considered a principal risk of investing in the Fund, regardless of the order in which it appears. The significance of each risk factor below may change over time and you should review each risk factor carefully.

Mortgage-Backed Pass-Through Securities Risk is the risk of investing in mortgage-backed securities issued by a US Agency. Mortgage-backed securities may be less liquid than other bonds, and may be more sensitive than other bonds to the market’s perception of issuers and creditworthiness of payees, particularly in declining general economic conditions when concern regarding mortgagees’ ability to pay (e.g., the ability of homeowners, commercial mortgagees, consumers with student loans, automobile loans or credit card debtholders to make payments on the underlying loan pools) rises, which may result in the Fund experiencing difficulty selling or valuing these securities. In addition, these securities may not be backed by the full faith and credit of the U.S. government, have experienced extraordinary weakness and volatility at various times in recent years, and may decline quickly in the event of a substantial economic or market downturn. Mortgage-backed securities are subject to Credit (or Default) Risk, Interest Rate/Maturity Risk, Debt Extension Risk and Prepayment (or Call) Risk. Because of these risks, mortgage-backed securities react differently to changes in interest rates than other bonds. Small movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain mortgage-backed securities. While agency mortgage-backed securities are guaranteed as to the timely payment of interest and principal by a government entity, they are not guaranteed as to market price, which will fluctuate.

U.S. Government Securities Risk is the risk that the U.S. government will not provide financial support to its agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law. Many U.S. government securities that may be purchased by the Fund are not backed by the full faith and credit of the United States. The maximum potential liability of the issuers of some U.S. government securities may greatly exceed their current resources,

including any legal right to support from the U.S. Treasury. It is possible that the issuers of such securities will not have the funds to meet their payment obligations in the future.

Income Risk is the risk that the Fund’s income may decline when interest rates fall. This decline can occur because the Fund must invest in lower-yielding bonds as bonds in its portfolio mature, bonds in the Underlying Index are substituted or the Fund otherwise needs to purchase additional bonds.

Cash Transactions Risk is the risk from the Fund effecting creation and redemption orders of its shares entirely for cash, rather than for in-kind securities. The Fund may have to sell portfolio securities at inopportune times in order to obtain the cash needed to meet redemption orders. This may cause the Fund to sell a security or other financial instrument and recognize a capital gain or loss that might not have been incurred if it had not effected a redemption order entirely for cash. As such, investments in Fund shares may be less tax-efficient than an investment in an ETF that meets redemption orders entirely in-kind with portfolio securities. The use of all cash creation and redemption orders may also cause the Fund’s shares to trade in the secondary market at wider bid-ask spreads and/or greater pre

158

FlexShares® Disciplined Duration MBS Index Fund (cont.)

miums or discounts to the Fund’s NAV. To the extent that the maximum additional variable charge for cash creation or cash redemption transactions is insufficient to cover the transaction costs of purchasing or selling portfolio securities, the Fund’s performance could be negatively impacted.

Authorized Participant Concentration Risk is the risk that the Fund may be adversely affected because it has a limited number of institutions that act as authorized participants

(“Authorized Participants”). Only an Authorized Participant may engage in creation or redemption transactions directly with the Fund and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to the Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units (as defined below), Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting.

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

159

FlexShares® Disciplined Duration MBS Index Fund (cont.)

•Financial Sector Risk is the risk that the financial sector can be significantly affected by changes in interest rates, government regulation, the rate of corporate and consumer debt defaulted, price competition, and the availability and cost of capital, among other factors.

Credit (or Default) Risk is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a TBA, repurchase or other transaction, to meet its payment or other financial obligations will adversely affect the value of the Fund’s investments and its returns. The credit quality of a debt security or of the issuer of a debt security held by the Fund could deteriorate rapidly, which may impair the Fund’s liquidity or cause a deterioration in the Fund’s NAV. The Fund could also be delayed or hindered in its enforcement of rights against an issuer, guarantor or counterparty. The degree of credit risk depends on the issuer’s or counterparty’s financial condition and on the terms of the securities.

Debt Extension Risk is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Fund later than expected. This will cause the value of the security, and the Fund’s NAV, to decrease, and the Fund may lose opportunities to invest in higher yielding securities.

NTI to correctly predict the direction of securities’ prices, interest rates, currency exchange rates and other economic factors, which may make the Fund’s returns more volatile or increase the risk of loss.

High Portfolio Turnover Risk is the risk that active and frequent trading of the Fund’s portfolio securities may result in increased transaction costs to the Fund, including brokerage commissions, dealer mark-ups and other transaction costs, which could reduce the Fund’s return.

Interest Rate/Maturity Risk is the risk that the value of the Fund’s fixed-income assets will decline because of rising interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. Changing interest rates, including rates that fall below zero, may have unpredictable effects on the markets and the Fund’s investments, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Fund, and may detract from Fund performance. A low or negative interest rate environment could cause the Fund’s earnings to fall below the Fund’s expense ratio, resulting in a negative yield and a decline in the Fund’s share price. An increase in interest rates may cause investors to move out of fixed incomes securities on a large scale, which could adversely affect the price of fixed income securities, lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments. The average effective duration of the Fund’s portfolio securities may be longer or shorter than the average effective duration of the MBS of the Underlying Index. Although the Underlying Index is designed so that the average effective duration of the MBS represented in the Index generally will range between 3.25

160

FlexShares® Disciplined Duration MBS Index Fund (cont.)

and 4.25 years, there is no guarantee that it will do so. The Fund will continue to seek to track the Underlying Index. There is also the risk that the Fund may have a longer or shorter average effective duration than that of the MBS in the Underlying Index as a result of tracking error. A portfolio of securities with a longer average effective duration is generally considered to have a higher risk profile than a portfolio with a shorter average effective duration.

Liquidity Risk is the risk that certain portfolio securities may be less liquid than others, which may make them difficult or impossible to sell at the time and the price that the Fund would like, adversely affecting the value of the Fund’s investments and its returns. Illiquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. Liquidity risk may result from the lack of an active market, reduced number and capacity of traditional market participants to make a market in fixed income securities, and may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. In such cases, the Fund, due to limitations on investments in illiquid securities and/or purchasing and selling such investments, may be unable to achieve a high degree of correlation with the Underlying Index. Additionally, in adverse market conditions, the Fund’s market price may begin to reflect illiquidity or pricing uncertainty of the Fund’s portfolio securities. This could lead to the Fund’s shares trading at a price that is higher or lower than the Fund’s NAV. At times, such differences may be significant.

Prepayment (or Call) Risk is the risk that an issuer could exercise its right to pay principal on callable debt securities held by the Fund earlier than expected. Issuers may be more likely to prepay when interest rates fall, when credit spreads change, or when an issuer’s credit quality improves. If this happens, the Fund will not benefit from the rise in the market price of the securities that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds in lower yielding securities, which may reduce the Fund’s returns. The Fund may also lose any premium it paid to purchase the securities.

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

The bar chart and table that follow show how the Fund has performed on a calendar year basis and provide an indication of the risks of investing in the Fund by showing (A) changes in the Fund’s performance from year to year and (B) how the Fund’s average annual returns compare with those of a broad measure of market performance. Past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated information on the Fund’s performance results can be obtained by visiting flexshares.com.

Calendar Year Total Returns

For the period shown in the bar chart above:

Best Quarter (12/31/2023): 5.35%

Worst Quarter (3/31/2022): -4.53%

161

FlexShares® Disciplined Duration MBS Index Fund (cont.)

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Since Inception of Fund	Inception Date of Fund
Before Taxes	4.62%	0.82%	0.98%	9/3/2014
After Taxes on Distributions	3.16%	-0.40%	-0.30%	—
After Taxes on Distributions and Sale of Shares	2.71%	0.13%	0.20%	—
ICE BofA® Constrained Duration US Mortgage Backed Securities IndexSM*	5.04%	1.36%	1.47%	—

Prior to July 1, 2022, index returns reflect no deduction for fees, expenses or taxes. Effective July 1, 2022, index returns reflect no deduction for taxes, but include transaction costs, which may be higher or lower than the actual transaction costs incurred by the Fund.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. David M. Alongi, a Senior Vice President of NTI, and Michael R. Chico and Kevin O’Shaughnessy, each a Vice President of NTI, have served as Portfolio Managers of the Fund since June 2021, September 2020 and May 2016, respectively.

Purchase and Sale of Fund Shares

on market price, and because ETF shares trade at market prices rather than NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). An investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase shares of the Fund (bid) and the lowest price a seller is willing to accept for shares of the Fund (ask) when buying or selling shares in the secondary market (“the bid-ask spread”). Recent information, including information about the Fund’s NAV, market price, premiums and discounts, and bid-ask spreads, is included on the Fund’s website at flexshares.com.

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

162

FlexShares® Credit-Scored US Corporate

Bond Index Fund

Ticker: SKOR

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Northern Trust US Corporate Bond Quality Value IndexSM (the “Underlying Index”).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)	0.15%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.16%
Expense Reimbursement(2)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.15%

(1)

“Management Fees” have been restated to reflect current fees.

(2)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.15%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$15
3 Years	$51
5 Years	$89
10 Years	$204

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a diversified universe of intermediate maturity, US-dollar denominated bonds of companies with investment grade credit quality, favorable valuations, and enhanced short-term and long-term solvency. Securities eligible for inclusion in the Underlying Index must meet the following criteria at each reconstitution of the Underlying Index: (a) they are issued in U.S. dollars; (b) they are publicly issued in the U.S. and registered with the SEC or eligible for resale under Rule 144A under the Securities Act of 1933; (c) they fall within a specified list of eligible security types; (d) they are either senior or subordinated debts; (e) they have a minimum credit rating of Baa3 or BBB-; (f) they have a final maturity of at least one year and up to (but not including) 10 years; and (g) they have $250 million or more in outstanding principal.

Once all eligible securities have been identified, the Underlying Index then follows a rules-based methodology to select and weight securities, subject to certain constraints as described below, to optimize the Underlying Index’s exposure to a combined proprietary value score and a proprietary quality score, as determined by NTI acting in its

163

FlexShares® Credit-Scored US Corporate Bond Index Fund (cont.)

capacity as index provider (“Index Provider”). Each of the value score and the quality score are based on various metrics obtained from company filings and recent price activity. The value score has multiple components, including: (a) valuation (e.g., to assess the relative value of the security versus other similar securities); (b) spread analysis (e.g., to assess the risk/return trade-off associated with each security versus other similar securities); and (c) solvency (e.g., to assess the corporation’s short term and long term solvency and also its risk of default). The quality score has three components: (i) management efficiency (e.g., corporate finance activities); (ii) profitability (e.g., reliability and sustainability of financial performance); and (iii) solvency. The primary objective of the optimization process is to maximize exposure to securities with the highest value and quality scores and to maintain a similar effective duration profile relative to the Underlying Index's eligible universe. In addition, the optimization process also includes security level, sector, issuer level, low value and quality, duration band, and turnover constraints to seek to manage systematic risk.

As of December 31, 2023, there were 2,776 issues in the Underlying Index. The Underlying Index is reconstituted monthly. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

NTI uses representative sampling strategy to manage the Fund. “Representative sampling” is investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index. The Fund may or may not hold all of the securities that are included in the Underlying Index. The Fund reserves the right to invest in substantially all of the securities in its Underlying Index in approximately the same proportions (i.e., replication) if NTI determines that it is in the best interest of the Fund.

ket funds advised by NTI or its affiliates, futures contracts and options on futures, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. As of December 31, 2023, the Underlying Index was concentrated in the financial sector. The components of the Underlying Index, and the degree to which these components represent certain industries or sectors, may change over time.

Principal Risks

Corporate Bond Risk. Corporate debt securities are subject to the risk of the issuer’s inability to meet principal and interest payments on the obligation and may also be subject to price volatility due to such factors as interest rate sensitivity, market perception of the creditworthiness of the issuer and general market liquidity. When interest rates rise, the value of corporate debt can be expected to decline. Debt securities with longer maturities tend to be more sensitive to interest rate movements than those with shorter maturities.

164

FlexShares® Credit-Scored US Corporate Bond Index Fund (cont.)

Quality-Value Score Risk is the risk that the Fund’s investment in companies whose securities are believed to be undervalued will not appreciate in value as anticipated or the past performance of companies that have exhibited quality characteristics does not continue. Although the Underlying Index is designed to measure the performance of a portfolio of bonds with certain characteristics, there is no assurance that the Underlying Index or Fund will be comprised of such securities or that the Underlying Index's optimization process will achieve the intended results.

result in the Fund’s shares trading at increased premiums or discounts to the Fund’s NAV. During periods of market disruption or other abnormal market conditions, the Fund’s exposure to the risks described elsewhere in this summary will likely increase.

Authorized Participant Concentration Risk is the risk that the Fund may be adversely affected because it has a limited number of institutions that act as authorized participants

165

FlexShares® Credit-Scored US Corporate Bond Index Fund (cont.)

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

also be delayed or hindered in its enforcement of rights against an issuer, guarantor or counterparty. The degree of credit risk depends on the issuer’s or counterparty’s financial condition and on the terms of the securities.

166

FlexShares® Credit-Scored US Corporate Bond Index Fund (cont.)

the Fund or the investment adviser, thus limiting the ability to implement the Fund’s strategies.

Liquidity Risk is the risk that certain portfolio securities may be less liquid than others, which may make them difficult or impossible to sell at the time and the price that the Fund would like, adversely affecting the value of the Fund’s investments and its returns. Illiquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. Liquidity Risk may result from the lack of an active market, reduced number and capacity of traditional market participants to make a market in fixed income securities, and may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. In such cases, the Fund, due to limitations on investments in illiquid securities and/or purchasing and selling such investments, may be unable to achieve a high degree of correlation with the Underlying Index. Additionally, in adverse market conditions, the Fund’s market price may begin to reflect illiquidity or pricing uncertainty of the Fund’s portfolio securities. This could lead to the Fund’s shares trading at a price that is higher or lower than the Fund’s NAV. At times, such differences may be significant.

Rule 144A Securities Risk is the risk that limitations on the resale of Rule 144A securities may have an adverse effect on their marketability and may prevent the Fund from disposing of them promptly at reasonable prices. There can be no assurance that an active trading market will exist at any time for such securities. Transaction costs may be higher for Rule 144A securities, and such securities may be difficult to value and may have significant volatility.

167

FlexShares® Credit-Scored US Corporate Bond Index Fund (cont.)

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance*

Calendar Year Total Returns

For the period shown in the bar chart above:

Best Quarter (6/30/2020): 8.08%

Worst Quarter (3/31/2022): -5.31%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Since Inception of Fund	Inception Date of Fund
Before Taxes	7.52%	2.85%	2.46%	11/12/2014
After Taxes on Distributions	5.78%	1.56%	1.26%	—
After Taxes on Distributions and Sale of Shares	4.41%	1.67%	1.38%	—
Bloomberg U.S. Intermediate Corporate Bond Index**	7.29%	2.64%	2.43%	—
Hybrid Northern Trust Credit-Scored US Corporate Bond IndexSM/Northern Trust US Corporate Bond Quality Value IndexSM***	7.80%	3.40%	3.22%	—

Effective May 1, 2020, the Fund’s principal investment strategies were revised.

Reflects no deduction for fees, expenses or taxes.

*** The hybrid index performance information reflects the performance of the Northern Trust Credit-Scored US Corporate Bond IndexSM (Previous Index) through April 30, 2020 and the Northern Trust US Corporate Bond Quality Value IndexSM thereafter. The Previous Index terminated as of May 1, 2020.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Chaitanya Mandavakuriti, CFA, a Vice President of NTI and Benjamin Gord, a Senior Vice President and Head of Fixed Income Portfolio Implementation of NTI, have served as Portfolio Managers of the Fund since March 2021 and May 2023, respectively.

Purchase and Sale of Fund Shares

The Fund is an exchange-traded fund (commonly referred to as an “ETF”). The Fund’s shares may be issued and

168

FlexShares® Credit-Scored US Corporate Bond Index Fund (cont.)

redeemed only by certain large institutions, referred to as “Authorized Participants,” that enter into agreements with the Fund’s principal underwriter. Retail investors may acquire and sell Fund shares in the secondary market through a broker-dealer. The price of Fund shares is based on market price, and because ETF shares trade at market prices rather than NAV, shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). An investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase shares of the Fund (bid) and the lowest price a seller is willing to accept for shares of the Fund (ask) when buying or selling shares in the secondary market (“the bid-ask spread”). Recent information, including information about the Fund’s NAV, market price, premiums and discounts, and bid-ask spreads, is included on the Fund’s website at flexshares.com.

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

169

FlexShares® Credit-Scored US Long

Corporate Bond Index Fund

Ticker: LKOR

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Northern Trust US Long Corporate Bond Quality Value IndexSM (the “Underlying Index”).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)	0.15%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.16%
Expense Reimbursement(2)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.15%

(1)

“Management Fees” have been restated to reflect current fees.

(2)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.15%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$15
3 Years	$51
5 Years	$89
10 Years	$204

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a diversified universe of longer term maturity, US-dollar denominated bonds of companies with investment grade credit quality, favorable valuations, and enhanced short-term and long-term solvency. Securities eligible for inclusion in the Underlying Index must meet the following criteria at each reconstitution of the Underlying Index: (a) they are issued in U.S. dollars; (b) they are publicly issued in the U.S. and registered with the SEC or eligible for resale under Rule 144A under the Securities Act of 1933; (c) they fall within a specified list of eligible security types; (d) they are either senior or subordinated debts; (e) they have a minimum credit rating of Baa3 or BBB-; (f) they have a final maturity of 10 years or greater; and (g) they have $250 million or more in outstanding principal.

170

FlexShares® Credit-Scored US Long Corporate Bond Index Fund (cont.)

prietary quality score, as determined by NTI acting in its capacity as index provider (“Index Provider”). Each of the value score and the quality score are based on various metrics obtained from company filings and recent price activity. The value score has multiple components, including: (a) valuation (e.g., to assess the relative value of the security versus other similar securities); (b) spread analysis (e.g., to assess the risk/return trade-off associated with each security versus other similar securities); and (c) solvency (e.g., to assess the corporation’s short term and long term solvency and also its risk of default). The quality score has three components: (i) management efficiency (e.g., corporate finance activities); (ii) profitability (e.g., reliability and sustainability of financial performance); and (iii) solvency. The primary objective of the optimization process is to maximize exposure to securities with the highest value and quality scores and to maintain a similar effective duration profile relative to the Underlying Index’s eligible universe. In addition, the optimization process also includes security level, sector, issuer level, low value and quality, duration band, and turnover constraints to seek to manage systematic risk.

As of December 31, 2023, there were 1,463 issues in the Underlying Index. The Underlying Index is reconstituted monthly. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

The Fund generally will invest under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of its Underlying

Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts and options on futures, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Principal Risks

Corporate Bond Risk is the risk the Fund faces because it invests primarily in bonds issued by corporations. Corporate debt securities are subject to the risk of the issuer’s inability to meet principal and interest payments on the obligation and may also be subject to price volatility due to such factors as interest rate sensitivity, market perception of the creditworthiness of the issuer and general market liquidity. When interest rates rise, the value of corporate debt can be expected to decline. Debt securities with longer maturities tend to be more sensitive to interest rate movements than those with shorter maturities.

171

FlexShares® Credit-Scored US Long Corporate Bond Index Fund (cont.)

Market Risk is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failure, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions or other events or adverse investor sentiment could have a significant impact on the Fund and its investments and could result in the Fund’s shares trading at increased premiums or discounts to the Fund’s NAV. During periods of market disruption or other abnormal market conditions, the Fund’s exposure to the risks described elsewhere in this summary will likely increase.

reconstitutes its portfolio in accordance with the Underlying Index, and, therefore, any changes to the Underlying Index’s rebalance and/or reconstitution schedule will result in corresponding changes to the Fund’s rebalance and/or reconstitution schedule.

172

FlexShares® Credit-Scored US Long Corporate Bond Index Fund (cont.)

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

173

FlexShares® Credit-Scored US Long Corporate Bond Index Fund (cont.)

Liquidity Risk is the risk that certain portfolio securities may be less liquid than others, which may make them difficult or impossible to sell at the time and the price that the Fund would like, adversely affecting the value of the Fund’s investments and its returns. Illiquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. Liquidity Risk may result from the lack of an active market, reduced number and capacity of traditional market participants to make a market in fixed income securities, and may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. In such cases, the Fund, due to limitations on investments in illiquid securities and/or purchasing and selling such investments, may be unable to achieve a high degree of correlation with the Underlying Index. Additionally, in adverse market conditions, the Fund’s market price may begin to reflect illiquidity or pricing uncertainty of the Fund’s portfolio securities. This could lead to the Fund’s shares trading at a price that is higher or lower than the Fund’s NAV. At times, such differences may be significant.

174

FlexShares® Credit-Scored US Long Corporate Bond Index Fund (cont.)

prepayment proceeds in lower yielding securities, which may reduce the Fund’s returns. The Fund may also lose any premium it paid to purchase the securities.

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance*

Calendar Year Total Returns

For the periods in the bar chart above:

Best Quarter (12/31/2023): 13.91%

Worst Quarter (6/30/2022): -12.95%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Since Inception of Fund	Inception Date of Fund
Before Taxes	12.39%	3.42%	3.46%	9/23/2015
After Taxes on Distributions	10.06%	1.49%	1.52%	—
After Taxes on Distributions and Sale of Shares	7.23%	1.96%	1.90%	—
Bloomberg Long U.S. Corporate Bond Index**	10.93%	2.87%	3.33%	—
Hybrid Northern Trust Credit-Scored US Long Corporate Bond IndexSM/Northern Trust US Long Corporate Bond Quality Value IndexSM***	12.14%	4.20%	5.35%	—

Effective May 1, 2020, the Fund’s principal investment strategies were revised.

Reflects no deduction for fees, expenses or taxes.

*** The hybrid index performance information reflects the performance of the Northern Trust Credit-Scored US Long Corporate Bond Index℠ (Previous Index) through April 30, 2020 and the Northern Trust US Long Corporate Bond Quality Value Index℠ thereafter. The Previous Index terminated as of May 1, 2020.

175

FlexShares® Credit-Scored US Long Corporate Bond Index Fund (cont.)

evant to investors who hold shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement plans. After-tax returns may exceed the return before taxes due to an assumed tax benefit from realizing a capital loss on a sale of Fund shares.

Management

Purchase and Sale of Fund Shares

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), NTI and its related

companies may pay the intermediary for activities related to the marketing and promotion of the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

176

FlexShares® High Yield Value-Scored

Bond Index Fund

Ticker: HYGV

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Northern Trust High Yield Value-Scored US Corporate Bond IndexSM (the “Underlying Index”).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.37%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.38%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.37%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.37%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$38
3 Years	$121
5 Years	$212
10 Years	$479

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a diversified universe of high yield, U.S.-dollar denominated bonds of companies exhibiting favorable fundamental qualities, market valuations and liquidity, as defined by NTI’s proprietary scoring models. The securities included in the Underlying Index are a subset of the securities included in the Northern Trust High Yield US Corporate Bond IndexSM (the “Parent Index”), which is a market-capitalization weighted index comprised of U.S. dollar-denominated high yield corporate bonds.

The Underlying Index begins with the Parent Index and then follows a rules-based methodology to select and weight securities, subject to certain constraints, to optimize exposure to a proprietary value score, credit score, and liquidity score, each as determined by NTI acting in its capacity as index provider (“Index Provider”).

The core components of the proprietary value score and proprietary credit score are based on quantitative rankings of various metrics obtained from company filings and recent price activity. The value score has multiple components, including: (a) valuation (e.g., to assess the relative

177

FlexShares® High Yield Value-Scored Bond Index Fund (cont.)

value of the security versus other similar securities); (b) spread analysis (e.g., to assess the risk/return trade-off associated with each security versus other similar securities); and (c) solvency (e.g., to assess the corporation’s short term and long term solvency and also its risk of default). The credit score has three components: (i) management efficiency (e.g., corporate finance activities); (ii) profitability (e.g., reliability and sustainability of financial performance); and (iii) solvency. The core components of the proprietary liquidity score are based on a quantitative ranking of security characteristics obtained from company filings. Examples of data sets utilized to determine the liquidity score include: (x) time to maturity (e.g., time until the security reaches its maturity date as measured in in years); (y) total issuer debt outstanding (e.g., the sum of all debt outstanding for a single corporate issuer); and (z) time since original issuance (e.g., the time that has elapsed since the security was originally issued as measured in years). The primary objective of the optimization process is to maximize exposure to the value score relative to the Underlying Index's eligible universe. In addition, the optimization process also includes issuer level, sector, effective duration, low credit and liquidity score, duration band, and turnover constraints to seek to manage systematic risk.

The inception date of the Underlying Index was April 30, 2018. As of December 31, 2023, there were 952 issues in the Underlying Index. The Underlying Index is reconstituted monthly. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

NTI intends to use representative sampling strategy to manage the Fund. “Representative sampling” is investing in a representative sample of securities that collectively has an investment profile similar to the Underlying Index. The Fund may or may not hold all of the securities that are included in the Underlying Index. The Fund reserves the right to invest in substantially all of the securities in its Underlying Index in approximately the same proportions (i.e., replication) if NTI determines that it is in the best interest of the Fund.

The Fund generally will invest under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of its Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts and options on futures, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approximately the same extent that the Underlying Index is concentrated. As of December 31, 2023, the Underlying Index was concentrated in the industrials and consumer discretionary sectors. The components of the Underlying Index, and the degree to which these components represent certain industries or sectors, may change over time.

Principal Risks

High Yield Securities Risk is the risk that the Fund will be subject to greater credit risk, price volatility and risk of loss than if it invested primarily in investment grade securities, which can adversely impact the Fund’s return and NAV.

178

FlexShares® High Yield Value-Scored Bond Index Fund (cont.)

High yield securities are considered highly speculative and are subject to increased risk of an issuer’s inability to make principal and interest payments. The Underlying Index is designed to be comprised of securities with the potential for higher yields as compared to the overall high yield corporate bond market. As such, the Fund is expected to exhibit greater sensitivity to market fluctuations.

Distressed Securities Risk is the substantial risk of investing in distressed securities that is in addition to the risks of investing in non-investment grade securities generally. NTI defines securities issued by companies whose financial condition is troubled or uncertain and that may be involved in bankruptcy proceedings, reorganizations or financial restructurings as “distressed securities.” Distressed securities are speculative and involve a substantial risk that principal will not be paid. In addition, the Fund will generally not receive interest payments on the distressed securities and may incur costs to protect its investment. These securities may present a substantial risk of default. The Fund may incur additional expenses to the extent it is required to seek recovery upon a default in the payment of principal of or interest on its portfolio holdings. In any reorganization or liquidation proceeding relating to a portfolio company, the Fund may lose its entire investment or may be required to accept cash or securities with a value less than its original investment. Distressed securities and any securities received in an exchange for such securities may be subject to restrictions on resale.

Substantial Volatility Risk is the risk that the value of the securities in the Fund’s portfolio may fluctuate, sometimes rapidly and unpredictably at a greater level than the overall market. There is a risk that the Fund could have substantial volatility.

Value Score Risk is the risk that the Fund’s investment in companies whose securities are believed to be undervalued will not appreciate in value as anticipated. Although the Underlying Index is designed to measure a portfolio of bonds of companies with the potential for higher yields and less risk of insolvency relative to the Parent Index, there is no assurance that the Underlying Index or Fund will be comprised of such securities. Accordingly, the Fund may be subject to greater credit risk, price volatility and risk of loss relative to the Parent Index.

Concentration Risk is the risk that, if the Fund is concentrated in a particular industry or group of industries, the Fund is likely to present more risks than a fund that is

179

FlexShares® High Yield Value-Scored Bond Index Fund (cont.)

Calculation Methodology Risk is the risk that the Underlying Index’s calculation methodology or sources of information may not provide an accurate assessment of included issuers or correct valuation of securities, nor is the availability or timeliness of the production of the Underlying Index guaranteed. A security included in the Underlying Index may not exhibit the characteristic or provide the specific exposure for which it was selected and consequently a Fund's holdings may not exhibit returns consistent with that characteristic or exposure.

180

FlexShares® High Yield Value-Scored Bond Index Fund (cont.)

portionate losses to the Fund. Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

and of the Fund, and may detract from Fund performance. A low or negative interest rate environment could cause the Fund’s earnings to fall below the Fund’s expense ratio, resulting in a negative yield and a decline in the Fund’s share price. An increase in interest rates may cause investors to move out of fixed incomes securities on a large scale, which could adversely affect the price of fixed income securities, lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments.

Liquidity Risk is the risk that certain portfolio securities may be less liquid than others, which may make them difficult or impossible to sell at the time and the price that the Fund would like, adversely affecting the value of the Fund’s investments and its returns. Illiquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. Liquidity Risk may result from the lack of an active market, reduced number and capacity of traditional market participants to make a market in fixed income securities, and may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. In such cases, the Fund, due to limitations on investments in illiquid securities and/or purchasing and selling such investments, may be unable to achieve a high degree of correlation with the Underlying Index. Additionally, in adverse market conditions, the Fund’s market price may begin to reflect illiquidity or pricing uncertainty of the Fund’s portfolio securities. This could lead to the Fund’s shares trading at a price that is higher or lower than the Fund’s NAV. At times, such differences may be significant.

181

FlexShares® High Yield Value-Scored Bond Index Fund (cont.)

triate assets, and may also impose taxes. Any of these events could cause the value of the Fund’s investments to decline. Foreign banks, agents and securities depositories that hold the Fund’s foreign assets may be subject to little or no regulatory oversight over, or independent evaluation, of their operations. Additional costs associated with investments in foreign securities may include higher custodial fees than those applicable to domestic custodial arrangements and transaction costs of foreign currency conversions. Unless the Fund has hedged its foreign currency exposure, foreign securities risk also involves the risk of negative foreign currency rate fluctuations, which may cause the value of securities denominated in such foreign currency (or other instruments through which the Fund has exposure to foreign currencies) to decline in value. Currency exchange rates may fluctuate significantly over short periods of time. Currency hedging strategies, if used, are not always successful. For instance, forward foreign currency exchange contracts, if used by the Fund, could reduce performance if there are unanticipated changes in currency exchange rates.

the securities in the Fund’s portfolio may change on days when shareholders will not be able to purchase or sell the Fund’s shares.

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

Calendar Year Total Returns

For the periods in the bar chart above:

Best Quarter (6/30/2020): 11.06%

Worst Quarter (3/31/2020): -14.42%

182

FlexShares® High Yield Value-Scored Bond Index Fund (cont.)

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Five Year	Since Inception of Fund	Inception Date of Fund
Before Taxes	12.98%	5.41%	4.14%	7/17/2018
After Taxes on Distributions	8.95%	2.46%	1.07%	—
After Taxes on Distributions and Sale of Shares	7.53%	2.89%	1.83%	—
ICE BofA® US High Yield Index*	13.46%	5.21%	4.21%	—
Northern Trust High Yield Value-Scored US Corporate Bond IndexSM**	14.85%	6.89%	5.58%	—

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Eric R. Williams, a Senior Vice President of NTI, Chaitanya Mandavakuriti, CFA, a Vice President of NTI, and Benjamin Gord, a Senior Vice President and Head of Fixed Income Portfolio Implementation of NTI, have served as Portfolio Managers of the Fund since June 2020, May 2023 and May 2023, respectively.

Purchase and Sale of Fund Shares

The Fund is an exchange-traded fund (commonly referred to as an “ETF”). The Fund’s shares may be issued and

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

183

FlexShares® ESG & Climate Investment

Grade Corporate Core Index Fund

Ticker: FEIG

Investment Objective

The Fund seeks investment results that correspond generally to the price and yield performance, before fees and expenses, of the Northern Trust ESG & Climate Investment Grade U.S. Corporate Core IndexSM (the “Underlying Index”).

Fees and Expenses of the Fund

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees	0.12%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.13%
Expense Reimbursement(1)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.12%

(1)

Northern Trust Investments, Inc. (“NTI”) has contractually agreed to reimburse a portion of the operating expenses of the Fund (other than 12b-1 Fees, Tax Expenses, Extraordinary Expenses, and Acquired Fund Fees and Expenses) to the extent the “Total Annual Fund Operating Expenses” exceed 0.12%. This contractual limitation may not be terminated before March 1, 2025 without the approval of the Fund’s Board of Trustees. The Fund’s Board of Trustees may terminate the contractual agreement at any time if it determines that it is in the best interest of the Fund and its shareholders.

Example

1 Year	$12
3 Years	$41
5 Years	$72
10 Years	$165

Principal Investment Strategies

The Underlying Index is designed to reflect the performance of a selection of U.S.-dollar-denominated corporate bonds issued by companies that exhibit certain environmental, social and governance (“ESG”) characteristics. The Underlying Index is designed to minimize tracking differences relative to the Northern Trust Investment Grade U.S. Corporate Bond IndexSM (the “Parent Index”) while also seeking (a) an aggregate higher scoring of certain ESG characteristics, as measured by the Northern Trust ESG Vector Score (“ESG Vector Score”) described below, and (b) reduction of aggregate climate-related risk, as measured by certain carbon-related risk metrics, each relative to its Parent Index. The Underlying Index also excludes certain companies by using controversial business involvement and norms-based screens.

The Parent Index is a market-capitalization weighted index comprised of US dollar-denominated corporate bonds. In order to be eligible for inclusion in the Parent Index, a security must be a US-dollar-denominated corporate bond that is publicly issued in the United States and registered with the SEC or eligible for resale under Rule 144A under the Securities Act of 1933, with or without registration

184

FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund (cont.)

rights. A security must be an investment grade security (i.e., rated at the time of inclusion in the Parent Index within the top four ratings categories by a Nationally Recognized Statistical Rating Organization (“NRSRO”)). In addition, a security eligible for inclusion in the Parent Index must have, at each rebalance, (i) a final time to stated maturity of at least one year and (ii) an outstanding principal balance of at least $250 million. The Fund does not have any portfolio maturity limitation and may invest its assets from time to time in instruments with varying maturities.

NTI in its capacity as Index Provider (the “Index Provider”) applies an ESG Vector Score to each of the companies in the Parent Index. The ESG Vector Score is designed to rank companies based on their management of and exposure to material ESG metrics as defined by the Sustainability Accounting Standards Board (“SASB”) Standards and a corporate governance score for each company. NTI calculates and maintains ESG Vector Scores for companies using data from third-party data providers. The SASB Standards identify financially material ESG issues for a company based on its industry classification within the following five dimensions: (i) environmental; (ii) social capital; (iii) human capital; (iv) business model and innovation; and (v) leadership and governance. The preliminary ESG score is then adjusted up or down based on a quantitative assessment of how a company is managing the risks associated with those material ESG issues relative to its peers based on the recommendations of the Task Force on Climate-related Financial Disclosures to evaluate a company through governance, strategy and risk management lenses. The adjusted ESG score generates 80% of the ESG Vector Score. Finally, a distinct corporate governance score is applied to each company with respect to its (i) board and management quality and integrity; (ii) board structure; (iii) ownership and shareholder rights; (iv) remuneration; (v) financial reporting; and (vi) stakeholder governance, which generates 20% of the ESG Vector Score.

In addition to applying the ESG Vector Score, the Index Provider uses data from Institutional Shareholder Services ESG Solutions to assess carbon emissions intensity and a carbon risk rating for each company. Carbon emissions intensity measures (i) direct greenhouse gas emissions from sources controlled or owned by the company (e.g., emissions associated with fuel combustion in boilers, furnaces, or vehicles); and (ii) indirect greenhouse gas emis

sions associated with the purchase of electricity, steam, heat or cooling against the value of the company enterprise-wide. The ISS Carbon Risk Rating provides an assessment of a company’s ability to mitigate the risks of transition to a lower carbon economy based on its specific baseline carbon risk exposure.

At the time of each reconstitution of the Underlying Index, the Index Provider uses an optimization process to select and weight securities in the Parent Index to seek to (i) minimize the potential for tracking differences for the Underlying Index; (ii) increase the aggregate ESG Vector Score for the companies in the Underlying Index; (iii) reduce the aggregate carbon emissions intensity of the companies in the Underlying Index; and (iv) improve the aggregate carbon risk rating of the companies in the Underlying Index, each relative to the Parent Index. It is possible that the Underlying Index will include (and therefore the Fund could invest in) securities that, individually, have a low ESG Vector Score or high carbon-related risk relative to the aggregate ESG score or carbon-related risk of the Parent Index. The optimization also includes sector, country, turnover, issuer and constituent constraints so that these characteristics in the Underlying Index vary within acceptable bands relative to the Parent Index.

185

FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund (cont.)

The Underlying Index is a new index with an inception date of July 30, 2021. As of December 31, 2023, there were 3,679 issues in the Underlying Index. The Underlying Index is reconstituted monthly under normal market conditions. The Fund generally reconstitutes its portfolio in accordance with the Underlying Index.

Under normal circumstances, the Fund will invest at least 80% of its total assets (exclusive of collateral held from securities lending) in the securities of the Underlying Index. The Fund may also invest up to 20% of its assets in cash and cash equivalents, including shares of money market funds advised by NTI or its affiliates, futures contracts and options on futures contracts, as well as securities not included in the Underlying Index, but which NTI believes will help the Fund track its Underlying Index.

The Fund may lend securities representing up to one-third of the value of the Fund’s total assets (including the value of the collateral received).

The Fund is “non-diversified” under the Investment Company Act of 1940 (“1940 Act”), as amended, and may invest more of its assets in fewer issuers than “diversified” funds.

Industry Concentration Policy. The Fund will concentrate its investments (i.e., hold 25% or more of its total assets) in a particular industry or group of industries to approxi

mately the same extent that the Underlying Index is concentrated. As of December 31, 2023, the Underlying Index was concentrated in the financial sector. The components of the Underlying Index, and the degree to which these components represent certain industries or sectors, may change over time.

Principal Risks

186

FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund (cont.)

the assessment by the Index Provider or a data provider. Investors can differ in their views of what constitutes positive or negative ESG characteristics. As a result, the Fund may invest in companies that do not reflect the beliefs and values of any particular investor. A company included in the Underlying Index may not exhibit positive or favorable ESG characteristics. The companies selected by the Index Provider as demonstrating certain ESG characteristics may not be the same companies selected by other index providers or investment managers as exhibiting those characteristics.

The Index Provider relies on various sources of information regarding an issuer, including information that may be based on assumptions and estimates. ESG information from third-party data providers may be incomplete, inaccurate or unavailable. Neither the Fund nor NTI can offer assurances that the Underlying Index’s methodology or sources of information will provide an accurate assessment of the issuers of the securities included in the Fund’s Underlying Index. The Index Provider uses third-party data that it believes to be reliable, but it does not guarantee the accuracy of such third-party data. Data can vary across providers or within industries. ESG standards differ by region and industry, and a company’s ESG practices or the Index Provider’s or data providers’ assessment of a company’s ESG practices may change over time. Regulatory changes or interpretations regarding the definitions and/or use of ESG criteria could have a material adverse effect on the Fund’s ability to invest in accordance with its investment policies and/or achieve its investment objective.

ments and its returns. The credit quality of a debt security or of the issuer of a debt security held by the Fund could deteriorate rapidly, which may impair the Fund’s liquidity or cause a deterioration in the Fund’s NAV. The Fund could also be delayed or hindered in its enforcement of rights against an issuer, guarantor or counterparty. The degree of credit risk depends on the issuer’s or counterparty’s financial condition and on the terms of the securities.

Income Risk is the risk that the Fund’s income may decline when interest rates fall. This decline can occur because the

187

FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund (cont.)

Fund must invest in lower-yielding bonds as bonds in its portfolio mature, bonds in the Underlying Index are substituted or the Fund otherwise needs to purchase additional bonds.

demics) or other public health issues, recessions or other events or adverse investor sentiment could have a significant impact on the Fund and its investments and could result in the Fund’s shares trading at increased premiums or discounts to the Fund’s NAV. During periods of market disruption or other abnormal market conditions, the Fund’s exposure to the risks described elsewhere in this summary will likely increase.

Liquidity Risk is the risk that certain portfolio securities may be less liquid than others, which may make them difficult or impossible to sell at the time and the price that the Fund would like, adversely affecting the value of the Fund’s investments and its returns. Illiquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. Liquidity Risk may result from the lack of an active market, reduced number and capacity of traditional market participants to make a market in fixed income securities, and may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. In such cases, the Fund, due to limitations on investments in illiquid securities and/or purchasing and selling such investments, may be unable to achieve a high degree of correlation with the Underlying Index. Additionally, in adverse market conditions, the Fund’s market price may begin to reflect illiquidity or pricing uncertainty of the Fund’s portfolio securities. This could lead to the Fund’s shares trading at a price that is higher or lower than the Fund’s NAV. At times, such differences may be significant.

Index Risk is the risk that the Fund would not necessarily buy or sell a security unless that security is added to or removed from, respectively, the Underlying Index, even if

188

FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund (cont.)

that security generally is underperforming, because unlike many investment companies, the Fund does not utilize an investing strategy that seeks returns in excess of the Underlying Index. Additionally, the Fund rebalances and/or reconstitutes its portfolio in accordance with the Underlying Index, and, therefore, any changes to the Underlying Index’s rebalance and/or reconstitution schedule will result in corresponding changes to the Fund’s rebalance and/or reconstitution schedule.

189

FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund (cont.)

to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.

It is possible to lose money on an investment in the Fund. An investment in the Fund is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.

Fund Performance

190

FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund (cont.)

Calendar Year Total Returns

For the periods shown in the bar chart above:

Best Quarter (12/31/2023): 8.32%

Worst Quarter (3/31/2022): -7.45%

Average Annual Total Returns

(for the periods ended December 31, 2023)

	One Year	Since Inception of Fund	Inception Date of Fund
Before Taxes	8.59%	-4.67%	9/20/2021
After Taxes on Distributions	6.68%	-5.99%	—
After Taxes on Distributions and Sale of Shares	5.03%	-4.09%	—
Bloomberg US Corporate Total Return Value Unhedged Index*	8.52%	-4.39%	—
Northern Trust ESG & Climate Investment Grade US Corporate Core IndexSM*	8.53%	-4.41%	—

Reflects no deduction for fees, expenses or taxes.

Management

Investment Adviser and Portfolio Managers. NTI, a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of the Fund. Mousumi Chinara, CFA, and

Michael R. Chico, each a Vice President of NTI, have served as Portfolio Managers of the Fund since July 2023.

Purchase and Sale of Fund Shares

Tax Information

Payments to Brokers-Dealers and Other Financial Intermediaries

191

Broad-Based Securities Market Indices

Bloomberg U.S. Intermediate Corporate Bond Index is an index that measures the investment grade, fixed-rate, taxable corporate bond market.

Bloomberg Long U.S. Corporate Bond Index is an index that is designed to measure the performance of U.S. corporate bonds that have a maturity of greater than or equal to 10 years.

FTSE EPRA/NAREIT Developed IndexSM is a free-float adjusted, market capitalization-weighted index designed to track the performance of listed real estate companies in developed countries worldwide.

ICE BofA® US High Yield Index is an index that tracks the performance of US dollar denominated 30-year, 20-year and 15-year fixed rate residential mortgage pass-through securities publicly issued by US agencies in the US domestic market.

MSCI ACWI Index is a market capitalization weighted index designed to provide a broad measure of equity-market performance throughout the world.

MSCI ACWI ex USA Index is an index that captures large- and mid-cap representation across 22 of 23 Developed Markets countries, excluding the United States.

MSCI WORLD INDEX captures large and mid cap representation across 23 Developed Markets countries. With 1,585 constituents, the index covers approximately 85% of the free ﬂoat-adjusted market capitalization in each country.

MSCI EMERGING MARKETS INDEX captures large and mid cap representation across 24 Emerging Markets countries. With 1,377 constituents, the index covers approximately 85% of the free ﬂoat-adjusted market capitalization in each country.

MSCI WORLD EX USA INDEX captures large and mid cap representation across 22 of 23 Developed Markets countries excluding the United States. With 964 constituents, the index covers approximately 85% of the free ﬂoat-adjusted market capitalization in each country.

Russell 1000® Index is a free float-adjusted market capitalization index which measures the performance of the 1,000 largest companies in the Russell 3000 Index, based on market capitalization.

S&P 500 Index is a free float-adjusted market capitalization index consisting of 500 stocks and is a widely recognized common measure of the performance of the overall U.S. stock market.

192

Additional Fund Information

This Prospectus describes twenty-eight (28) Funds, which are currently offered by the FlexShares® Trust (the “Trust”) and provides information you need to make an informed decision about investing in the Funds. Please read this Prospectus carefully before you make any investment decisions. Additional information regarding the Funds is available at flexshares.com.

Northern Trust Investments, Inc. (“NTI” or the “Investment Adviser”) is the investment adviser to each Fund. Shares of the Funds are listed for trading on NYSE Arca, Inc. (other than shares of the FlexShares® Real Assets Allocation Index Fund and FlexShares® Credit-Scored US Corporate Bond Index Fund which are listed for trading on the Nasdaq Stock Market LLC (“Nasdaq”), and FlexShares® Morningstar US Market Factor Tilt Index Fund, FlexShares® US Quality Large Cap Index Fund, FlexShares® STOXX® US ESG Select Index Fund, FlexShares® STOXX® Global ESG Select Index Fund and FlexShares® Credit-Scored US Long Corporate Bond Index Fund, which are listed for trading on the Cboe BZX Exchange, Inc. (“Cboe BZX”). The market price for a share of a Fund may be different from that Fund’s most recent net asset value (“NAV”) per share.

Each Fund is designed to track an index. Each share of a Fund represents a partial ownership in an underlying portfolio of securities intended to track a market index. Unlike shares of mutual funds, which can be bought and redeemed from the issuing fund by all shareholders at a price based on NAV, shares of the Funds may be purchased or redeemed directly from the Funds at NAV solely by institutions that act as authorized participants (“Authorized Participants”). Also unlike shares of mutual funds, shares of the Funds are listed on a national securities exchange and trade in the secondary market at market prices that change throughout the day.

Each Fund may use a representative sampling or replication strategy to manage the Fund. “Representative sampling” is investing in a representative sample of securities that collectively has an investment profile similar to the Fund’s Underlying Index. Securities selected are expected to have, in the aggregate, investment characteristics (based on factors such as market capitalization and industry weightings), fundamental characteristics (such as return

variability, duration, maturity and yield) and liquidity measures similar to those of the Underlying Index. The Fund may or may not hold all of the securities that are included in the Underlying Index. “Replication” is an indexing strategy in which a Fund invests in substantially all of the securities in its Underlying Index in approximately the same proportions as in the Underlying Index.

In addition to tracking the performance of an Underlying Index for each Fund, the Investment Adviser seeks to minimize portfolio turnover and tax inefficiencies.

The FlexShares® Real Assets Allocation Index Fund allocates and reallocates its assets among its Underlying Funds consistent with the allocation and reallocation of shares of the Underlying Funds in the Underlying Index, as determined by the Index Provider. Each of the Underlying Funds seek investment results that correspond generally to the price and yield performance, before fees and expenses, of its underlying index. In managing each of the Underlying Funds, the Investment Adviser uses a representative sampling index strategy.

Each Fund invests in a particular segment of the securities markets and seeks to track the performance of a securities index that generally is not representative of the market as a whole. Each Fund is designed to be used as part of broader asset allocation strategies. Accordingly, an investment in a Fund should not constitute a complete investment program.

An index is a theoretical financial calculation while each Fund is an actual investment portfolio. The performance of a Fund and its respective Underlying Index may vary due to transaction costs, non-U.S. currency valuations, asset valuations, corporate actions (such as mergers and spin-offs), timing variances, and differences between the Fund’s portfolio and its Underlying Index resulting from legal restrictions (such as diversification requirements) that apply to the Fund but not to the Underlying Index or to the use of representative sampling. “Tracking error” is the divergence of the performance (return) of a Fund’s portfolio from that of its Underlying Index. NTI expects that, over time, each Fund’s tracking error will not exceed 5%. To the extent a Fund uses a representative sampling indexing strategy, it can be expected to have a larger tracking error than if it used a replication indexing strategy. Tracking variance is

193

Additional Fund Information (cont.)

monitored by the Investment Adviser at least quarterly by comparing the performance of the Underlying Index to the performance of the Fund. In the event the performance of a Fund is not comparable to the performance of its Underlying Index, the Board of Trustees of the Trust (the “Board of Trustees”) will evaluate the reasons for the deviation and the availability of corrective measures.

Each Fund’s investment objective and its respective Underlying Index may be changed without shareholder approval. Each Fund has adopted a policy to provide its shareholders with at least 60 days’ prior written notice of any change to the Fund’s investment objective or its respective Underlying Index. If the Index Provider no longer calculates an Underlying Index of a Fund, if the Underlying Index is terminated for any reason, if the identity or the character of the Underlying Index is materially changed, or for any other reason determined by the Board of Trustees in good faith, the Board of Trustees determines that it is impracticable to substitute a replacement index, it will take whatever action is deemed to be in the best interests of the Fund’s shareholders.

On each business day, before commencement of trading on the Listing Exchange, each Fund will disclose on flexshares.com the identities and quantities of each Fund’s portfolio holdings that will form the basis for each Fund’s calculation of NAV at the end of the business day.

Additional Information about the FlexShares® Developed Markets ex-US Quality Low Volatility Index Fund and FlexShares® ESG & Climate Developed Markets ex-US Core Index Fund. As of December 31, 2023, the Index Provider classifies the following as developed market countries outside of the U.S.: Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, Netherlands, New Zealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland and United Kingdom. The Index Provider determines the Large/Mid Cap companies within developed market countries at each Index reconstitution using the following formula: Developed market companies are sorted by their full market capitalization, and the full market capitalization of the smallest company within the top 85% is the Initial Large/Mid Cap Threshold. Developed Market Large/Mid

Cap companies are those with market capitalization of at least 75% of the Initial Large/Mid Cap Threshold.

Additional Information about FlexShares® Emerging Markets Quality Low Volatility Index Fund and FlexShares® ESG & Climate Emerging Markets Core Index Fund. As of December 31, 2023, the Index Provider classifies the following as emerging market countries: Brazil, Chile, China, Colombia, Czech Republic, Egypt, Greece, Hungary, India, Indonesia, Kuwait, Malaysia, Mexico, Morocco, Peru, Philippines, Poland, Qatar, Saudi Arabia, South Africa, South Korea, Taiwan, Thailand, Turkey and United Arab Emirates. The Index Provider determines the Large/Mid Cap companies within emerging market countries at each Index reconstitution using the following formula: Emerging market companies are sorted by their full market capitalization, and the full market capitalization of the smallest company within the top 85% is the Initial Large/Mid Cap Threshold. Emerging Market Large/Mid Cap companies are those with market capitalization of at least 37.5% of the Initial Large/Mid Cap Threshold.

194

Additional Fund Information (cont.)

Additional Information About the Funds’ Principal Risks

All investments carry some degree of risk that will affect the value of a Fund’s investments, its investment performance and the price of its shares. As a result, loss of money is a risk of investing in each Fund. This section takes a closer look at some of the Funds’ principal risks described under the “Fund Summary” for each Fund. A risk may still apply to a Fund although it is not a principal risk of investing in the Fund.

The FlexShares® Real Assets Allocation Index Fund may be exposed to these risks directly, or indirectly through the Fund’s investments in the Underlying Funds.

The table below lists the principal risks that are discussed in each “Fund Summary” above and in this section.

FlexShares® US Quality
Low Volatility Index Fund

FlexShares® Developed
Markets ex-US Quality
Low Volatility Index Fund

FlexShares® Emerging
Markets Quality
Low Volatility Index Fund

FlexShares® Morningstar
US Market Factor
Tilt Index Fund

FlexShares® Morningstar
Developed Markets ex-US
Factor Tilt Index Fund

FlexShares® Morningstar
Emerging Markets Factor
Tilt Index Fund

FlexShares® US Quality
Large Cap Index Fund

FlexShares® STOXX® US ESG
Select Index Fund

FlexShares® STOXX® Global
ESG Select Index Fund

FlexShares® ESG & Climate
US Large Cap Core Index Fund

FlexShares® ESG & Climate
Developed Markets
ex-US Core Index Fund

FlexShares® ESG & Climate
Emerging Markets Core
Index Fund

FlexShares® Morningstar
Global Upstream Natural
Resources Index Fund

Authorized Participant

Concentration Risk

✓

Calculation Methodology

Risk

✓

Cash Transactions Risk

Concentration Risk

✓

Corporate Bond Risk

Credit (or Default) Risk

Debt Extension Risk

Depositary Receipts Risk

✓

Derivatives Risk

✓

Distressed Securities Risk

Dividend Risk

Emerging Markets Risk

✓

Equity Securities Risk

✓

ESG Investment Risk

✓

Foreign Securities Risk

✓

195

Additional Fund Information (cont.)

FlexShares® US Quality
Low Volatility Index Fund

FlexShares® Developed
Markets ex-US Quality
Low Volatility Index Fund

FlexShares® Emerging
Markets Quality
Low Volatility Index Fund

FlexShares® Morningstar
US Market Factor
Tilt Index Fund

FlexShares® Morningstar
Developed Markets ex-US
Factor Tilt Index Fund

FlexShares® Morningstar
Emerging Markets Factor
Tilt Index Fund

FlexShares® US Quality
Large Cap Index Fund

FlexShares® STOXX® US ESG
Select Index Fund

FlexShares® STOXX® Global
ESG Select Index Fund

FlexShares® ESG & Climate
US Large Cap Core Index Fund

FlexShares® ESG & Climate
Developed Markets
ex-US Core Index Fund

FlexShares® ESG & Climate
Emerging Markets Core
Index Fund

FlexShares® Morningstar
Global Upstream Natural
Resources Index Fund

Fund of Funds Risk

Geographic Risk

✓

High Portfolio Turnover Risk

High Yield Securities Risk

Income Risk

Index Risk

✓

Inflation Protected Security

Risk

Interest Rate Risk

Interest Rate/Maturity Risk

LIBOR Risk

Liquidity Risk

Low Volatility Risk

✓

Market Risk

✓

Market Trading Risk

✓

Mid and/or Small Cap

Stock Risk

✓

MLP Risk

MLP Tax Risk

Model Risk

Momentum Risk

✓

Mortgage-Backed Pass-

Through Securities Risk

New Fund Risk

✓

Non-Diversification Risk

✓

196

Additional Fund Information (cont.)

FlexShares® US Quality
Low Volatility Index Fund

FlexShares® Developed
Markets ex-US Quality
Low Volatility Index Fund

FlexShares® Emerging
Markets Quality
Low Volatility Index Fund

FlexShares® Morningstar
US Market Factor
Tilt Index Fund

FlexShares® Morningstar
Developed Markets ex-US
Factor Tilt Index Fund

FlexShares® Morningstar
Emerging Markets Factor
Tilt Index Fund

FlexShares® US Quality
Large Cap Index Fund

FlexShares® STOXX® US ESG
Select Index Fund

FlexShares® STOXX® Global
ESG Select Index Fund

FlexShares® ESG & Climate
US Large Cap Core Index Fund

FlexShares® ESG & Climate
Developed Markets
ex-US Core Index Fund

FlexShares® ESG & Climate
Emerging Markets Core
Index Fund

FlexShares® Morningstar
Global Upstream Natural
Resources Index Fund

Prepayment (or Call) Risk

Quality Factor Risk

✓

Quality-Value Score Risk

Real Estate Securities Risk

REIT Risk

Sampling Risk

✓

Securities Lending Risk

✓

Seed Investor Risk

Substantial Volatility Risk

Tax Risk

Tracking Error Risk

✓

U.S. Government Securities

Risk

Valuation Risk

✓

Value Investing Risk

✓

Value Score Risk

Volatility Risk

197

Additional Fund Information (cont.)

	FlexShares® STOXX® Global Broad Infrastructure Index Fund	FlexShares® Global Quality Real Estate Index Fund	FlexShares® Real Assets Allocation Index Fund	FlexShares® Quality Dividend Index Fund	FlexShares® Quality Dividend Defensive Index Fund	FlexShares® International Quality Dividend Index Fund	FlexShares® International Quality Dividend Defensive Index Fund	FlexShares® International Quality Dividend Dynamic Index Fund	FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund	FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund	FlexShares® Disciplined Duration MBS Index Fund
Authorized Participant Concentration Risk	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Calculation Methodology Risk	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Cash Transactions Risk											✓
Concentration Risk	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Corporate Bond Risk
Credit (or Default) Risk											✓
Debt Extension Risk											✓
Depositary Receipts Risk	✓	✓				✓	✓	✓
Derivatives Risk	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Distressed Securities Risk
Dividend Risk				✓	✓	✓	✓	✓
Emerging Markets Risk	✓	✓	✓			✓	✓	✓
Equity Securities Risk	✓	✓	✓	✓	✓	✓	✓	✓
ESG Investment Risk
Foreign Securities Risk	✓	✓	✓			✓	✓	✓
Fund of Funds Risk			✓
Geographic Risk	✓	✓	✓			✓	✓	✓
High Portfolio Turnover Risk											✓
High Yield Securities Risk
Income Risk									✓	✓	✓
Index Risk	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Inflation Protected Security Risk									✓	✓
Interest Rate Risk	✓	✓	✓
Interest Rate/Maturity Risk									✓	✓	✓

198

Additional Fund Information (cont.)

	FlexShares® STOXX® Global Broad Infrastructure Index Fund	FlexShares® Global Quality Real Estate Index Fund	FlexShares® Real Assets Allocation Index Fund	FlexShares® Quality Dividend Index Fund	FlexShares® Quality Dividend Defensive Index Fund	FlexShares® International Quality Dividend Index Fund	FlexShares® International Quality Dividend Defensive Index Fund	FlexShares® International Quality Dividend Dynamic Index Fund	FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund	FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund	FlexShares® Disciplined Duration MBS Index Fund
LIBOR Risk
Liquidity Risk											✓
Low Volatility Risk
Market Risk	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Market Trading Risk	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Mid and/or Small Cap Stock Risk	✓	✓	✓	✓	✓	✓	✓	✓
MLP Risk	✓		✓
MLP Tax Risk	✓		✓
Model Risk			✓
Momentum Risk		✓	✓
Mortgage-Backed Pass-Through Securities Risk											✓
New Fund Risk
Non-Diversification Risk
Prepayment (or Call) Risk											✓
Quality Factor Risk		✓	✓	✓	✓	✓	✓	✓
Quality-Value Score Risk
Real Estate Securities Risk		✓	✓
REIT Risk	✓	✓	✓
Sampling Risk	✓	✓		✓	✓	✓	✓	✓			✓
Securities Lending Risk	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Seed Investor Risk
Substantial Volatility Risk
Tax Risk			✓
Tracking Error Risk	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓

199

Additional Fund Information (cont.)

	FlexShares® STOXX® Global Broad Infrastructure Index Fund	FlexShares® Global Quality Real Estate Index Fund	FlexShares® Real Assets Allocation Index Fund	FlexShares® Quality Dividend Index Fund	FlexShares® Quality Dividend Defensive Index Fund	FlexShares® International Quality Dividend Index Fund	FlexShares® International Quality Dividend Defensive Index Fund	FlexShares® International Quality Dividend Dynamic Index Fund	FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund	FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund	FlexShares® Disciplined Duration MBS Index Fund
U.S. Government Securities Risk											✓
Valuation Risk	✓	✓	✓			✓	✓	✓			✓
Value Investing Risk		✓	✓
Value Score Risk
Volatility Risk				✓	✓	✓	✓	✓

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Additional Fund Information (cont.)

	FlexShares® Credit- Scored U.S. Corporate Bond Index Fund	FlexShares® Credit- Scored US Long Corporate Bond Index Fund	FlexShares® High Yield Value-Scored Bond Index Fund	FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund
Authorized Participant Concentration Risk	✓	✓	✓	✓
Calculation Methodology Risk	✓	✓	✓	✓
Cash Transactions Risk
Concentration Risk	✓	✓	✓	✓
Corporate Bond Risk	✓	✓		✓
Credit (or Default) Risk	✓	✓	✓	✓
Debt Extension Risk	✓	✓	✓	✓
Depositary Receipts Risk
Derivatives Risk	✓	✓	✓	✓
Distressed Securities Risk			✓
Dividend Risk
Emerging Markets Risk
Equity Securities Risk
ESG Investment Risk				✓
Foreign Securities Risk	✓	✓	✓	✓
Fund of Funds Risk
Geographic Risk
High Portfolio Turnover Risk		✓	✓
High Yield Securities Risk			✓
Income Risk	✓	✓	✓	✓
Index Risk	✓	✓	✓	✓
Inflation Protected Security Risk
Interest Rate Risk
Interest Rate/Maturity Risk	✓	✓	✓	✓

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Additional Fund Information (cont.)

	FlexShares® Credit- Scored U.S. Corporate Bond Index Fund	FlexShares® Credit- Scored US Long Corporate Bond Index Fund	FlexShares® High Yield Value-Scored Bond Index Fund	FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund
LIBOR Risk
Liquidity Risk	✓	✓	✓	✓
Low Volatility Risk
Market Risk	✓	✓	✓	✓
Market Trading Risk	✓	✓	✓	✓
Mid and/or Small Cap Stock Risk
MLP Risk
MLP Tax Risk
Model Risk
Momentum Risk
Mortgage-Backed Pass-Through Securities Risk
New Fund Risk				✓
Non-Diversification Risk				✓
Prepayment (or Call) Risk	✓	✓	✓	✓
Quality Factor Risk
Quality-Value Score Risk	✓	✓
Real Estate Securities Risk
REIT Risk
Sampling Risk	✓	✓	✓	✓
Securities Lending Risk	✓	✓	✓	✓
Seed Investor Risk
Substantial Volatility Risk			✓
Tax Risk
Tracking Error Risk	✓	✓	✓	✓
U.S. Government Securities Risk

202

Additional Fund Information (cont.)

	FlexShares® Credit- Scored U.S. Corporate Bond Index Fund	FlexShares® Credit- Scored US Long Corporate Bond Index Fund	FlexShares® High Yield Value-Scored Bond Index Fund	FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund
Valuation Risk	✓	✓	✓	✓
Value Investing Risk
Value Score Risk			✓
Volatility Risk

Authorized Participant Concentration Risk. Only an Authorized Participant may engage in creation or redemption transactions directly with a Fund. The Funds have a limited number of institutions that act as Authorized Participants and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. To the extent that these institutions exit the business or are unable or unwilling to proceed with creation and/or redemption orders with respect to a Fund and no other Authorized Participant is able or willing to step forward to create or redeem Creation Units, Fund shares may trade at a discount to NAV and possibly face trading halts and/or delisting. This risk may be heightened for a Fund if it invests in non-U.S. securities or other securities or instruments that are less widely traded. Such securities or instruments often involve greater settlement and operational issues and capital costs for Authorized Participants.

Calculation Methodology Risk. The Funds’ Underlying Indexes rely on various sources of information to assess the criteria of issuers included in the Indexes, including information that may be based on assumptions and estimates. Neither the Funds, the Index Provider nor the Investment Adviser can offer assurances that an Index’s calculation methodology or sources of information will provide an accurate assessment of included issuers or correct valuation of securities, nor can they guarantee the availability or timeliness of the production of the Index.

Errors in respect of the quality, accuracy and completeness of the data used to compile an Underlying Index may occur from time to time and may not be identified and corrected by an Index Provider for a period of time or at all, particularly where the indices are less commonly used as benchmarks by funds or managers. Gains, losses or costs associated with errors of an Index Provider or its agents will generally be borne by the applicable Fund and its shareholders. Unusual market conditions may also cause an Index Provider to postpone a scheduled rebalance to an Underlying Index, which could cause the Underlying Index to vary from its normal or expected composition. The postponement of a scheduled rebalance in a time of market volatility could mean that constituents of the Underlying Index that would otherwise be removed at rebalance due to changes in market capitalizations, issuer credit ratings, or other reasons may remain, causing the performance and constituents of the Underlying Index to vary from those expected under normal conditions. Apart from scheduled rebalances, an Index Provider or its agents may also carry out additional ad hoc rebalances to an Underlying Index in order to, for example, reach certain weighting constraints, account for unusual market conditions or correct an error in the selection of index constituents.

A security included in an Underlying Index may not exhibit the characteristic or provide the specific exposure

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Additional Fund Information (cont.)

for which it was selected and consequently a Fund’s holdings may not exhibit returns consistent with that characteristic or exposure.

Cash Transactions Risk. Paying redemption proceeds entirely in cash rather than through in-kind delivery of portfolio securities may require a Fund to dispose of or sell portfolio securities or other assets at an inopportune time to obtain the cash needed to meet redemption orders. This may cause a Fund to sell a security or other financial instrument and recognize a capital gain or loss that might not have been incurred if it had not effected a redemption order entirely for cash. As a result, a Fund may pay out higher or lower annual capital gains distributions than ETFs that meet redemption orders entirely in-kind with portfolio securities. The use of all cash creations and redemption orders may also cause a Fund’s shares to trade in the secondary market at wider bid-ask spreads and/or greater premiums or discounts to the Fund’s NAV. To the extent that the maximum additional variable charge for cash creation or cash redemption transactions is insufficient to cover the transaction costs of purchasing or selling portfolio securities, a Fund’s performance could be negatively impacted.

Concentration Risk. A fund concentrated in an industry or group of industries is likely to present more risks than a fund that is broadly diversified over several industries or groups of industries. Compared to the broad market, an individual industry may be more strongly affected by changes in the economic climate, broad market shifts, moves in a particular dominant stock or regulatory changes.

•Financial Sector Risk. Companies in the U.S. and non-U.S. financials sector of the economy, including those in the banking industry, are often subject to extensive governmental regulation and intervention, which may adversely affect the scope of their activities, the prices they can charge and the amount of capital they must maintain. Governmental regulation may change frequently and may have significant adverse consequences for companies in the financial sector, including effects not intended by such regulation. The impact of recent or future regulation on any individual financial company, the banking industry or on the sector as a whole cannot be predicted. Certain risks may impact the value

of investments in the financial sector more severely than those of investments outside this sector, including the risks associated with companies that operate with substantial financial leverage. Companies in the financial sector may also be adversely affected by increases in interest rates and loan losses, decreases in the availability of money or asset valuations, credit rating downgrades and adverse conditions in other related markets. Insurance companies, in particular, may be subject to severe price competition and/or rate regulation, which may have an adverse impact on their profitability.

In the recent past, deterioration of the credit markets impacted a broad range of mortgage, asset backed, auction rate, sovereign debt and other markets, including U.S. and non-U.S. credit and interbank money markets, thereby affecting a wide range of financial institutions and markets. A number of large financial institutions have failed, have merged with stronger institutions or have had significant government infusions of capital. Instability in the financial markets has caused certain financial companies to incur large losses. Some financial companies experienced declines in the valuations of their assets, took actions to raise capital (such as the issuance of debt or equity securities), or even ceased operations. Some financial companies borrowed significant amounts of capital from government sources and may face future government-imposed restrictions on their businesses or increased government intervention. Those actions caused the securities of many financial companies to decline in value. The financial sector is particularly sensitive to fluctuations in interest rates.

•Natural Resources Sector Risk. Funds investing in companies engaged in natural resources activities and may be subject to greater risks and market fluctuations than funds with more diversified portfolios. The value of the Fund’s securities will fluctuate in response to market conditions generally, and will be particularly sensitive to the markets for those natural resources in which a particular issuer is involved. The values of natural resources may also fluctuate directly with respect to real and perceived inflationary trends and various economic and political developments. Natural resource industries throughout the world may be subject to greater political, environmental and other governmental regulation than many other industries.

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Additional Fund Information (cont.)

Changes in governmental policies and the need for regulatory approvals may have an adverse effect on the products and services of natural resources companies. For example, the exploration, development and distribution of coal, oil and gas in the U.S. are subject to significant federal and state regulation, which may affect rates of return on such investments and the kinds of services that may be offered to companies in those industries. In addition, many natural resource companies have been subject to significant costs associated with compliance with environmental and other safety regulations. The direction, type or effect of any future regulations affecting natural resource industries are virtually impossible to predict.

Commodity prices fluctuate for several reasons, including changes in market and economic conditions, the impact of weather on demand, the impact of interest rates and inflation on production and demand, levels of domestic production and imported commodities, energy conservation, domestic and foreign governmental regulation and taxation and the availability of local, intrastate and interstate transportation systems. Volatility of commodity prices, which may lead to a reduction in production or supply, may also negatively impact the performance of companies in natural resources industries that are involved in the transportation processing, storing, distribution or marketing of commodities. Volatility of commodity prices may also make it more difficult for companies in natural resources industries to raise capital to the extent the market perceives that their performance may be directly or indirectly tied to commodity prices.

•Information Technology Sector Risk. Investments in technology securities present special risk considerations. Technology companies may produce or use products or services that prove commercially unsuccessful, become obsolete or become adversely impacted by government regulation. Competitive pressures in the technology industry, both domestically and internationally, may affect negatively the financial condition of technology companies, and a substantial investment in technology securities may subject a Fund to more volatile price movements than a more diversified securities portfolio. In certain instances, technology securities may experience significant price movements caused by

disproportionate investor optimism or pessimism with little or no basis in fundamental economic conditions. Technology companies may have limited product lines, markets, financial resources or personnel. The products of technology companies may face obsolescence due to rapid technological developments, frequent and new product introduction, unpredictable changes in growth rates and competition for the services of qualified personnel. In addition to the foregoing risks, technology companies operating in the health sciences and healthcare sector may be subject to product liability litigation. As a result of these and other reasons, investments in the technology industry can experience sudden and rapid appreciation and depreciation.

In addition, a Fund may make substantial investments in companies that develop or sell computer hardware or software and peripheral products, including computer components, which present additional risks. These companies are often dependent on the existence and health of other products or industries and face highly competitive pressures, product licensing, trademark and patent uncertainties and rapid technological changes, which may have a significant effect on their financial condition. For example, an increasing number of companies and new product offerings can lead to price cuts and slower selling cycles, and many of these companies may be dependent on the success of a principal product, may rely on sole source providers and third-party manufacturers, and may experience difficulties in managing growth.

•Infrastructure-Related Companies Risk. Investments in infrastructure-related companies have greater exposure to the potential adverse economic, regulatory, political and other changes affecting such entities. Infrastructure-related companies are subject to a variety of factors that may adversely affect their business or operations including high interest costs in connection with capital construction programs, costs associated with compliance with and changes in environmental and other regulations, difficulty in raising capital in adequate amounts on reasonable terms in periods of high inflation and unsettled capital markets, the effects of surplus capacity, increased competition from other providers of services in a developing deregulatory environment, uncertainties concerning

205

Additional Fund Information (cont.)

the availability of fuel at reasonable prices, the effects of energy conservation policies and other factors. Additionally, infrastructure-related companies may be subject to regulation by various governmental authorities and may also be affected by governmental regulation of rates charged to customers, government budgetary constraints, service interruption due to environmental, operational or other mishaps and the imposition of special tariffs and changes in tax laws, regulatory policies and accounting standards.

Other factors that may affect the operations of infrastructure-related companies include innovations in technology that could render the way in which a company delivers a product or service obsolete, significant changes to the number of ultimate end-users of a company’s products, increased susceptibility to terrorist acts or political actions, risks of environmental damage due to a company’s operations or an accident, and general changes in market sentiment towards infrastructure and utilities assets.

Corporate Bond Risk. Corporate bonds are subject to the risk of the issuer’s inability to meet principal and interest payments on the obligation and may also be subject to price volatility due to such factors as interest rate sensitivity, market perception of the creditworthiness of the issuer and general market liquidity. When interest rates rise, the value of corporate debt can be expected to decline. Bonds with longer maturities tend to be more sensitive to interest rate movements than those with shorter maturities.

Credit (or Default) Risk. An issuer or guarantor of debt instruments or the counterparty to a derivatives contract, TBA agreement or repurchase agreement may be unable or unwilling to make its timely interest and/or principal payments or to otherwise honor its obligations. Debt instruments are subject to varying degrees of credit risk, which may be reflected in their credit ratings. There is a chance that a portfolio holding of a Fund will have its credit ratings downgraded or will default (i.e., fail to make scheduled interest or principal payments), or that the market’s perception of the issuer’s creditworthiness may worsen, which may reduce a Fund’s income level, impair a Fund’s liquidity and cause significant deterioration in NAV. The degree of credit risk depends on the issuer’s or

counterparty’s financial condition and on the terms of the securities.

In addition, there is no assurance that securities or companies issuing debt that has historically exhibited fundamentals consistent with investment grade ratings will continue to exhibit such fundamentals.

Debt Extension Risk. During periods of rising interest rates, an issuer will exercise its right to pay principal on certain debt securities held by a Fund later than expected. This will cause the value of the security, and the Fund's NAV, to decrease, and the Fund may lose opportunities to invest in higher yielding securities.

Depositary Receipts Risk. Foreign securities may trade in the form of depositary receipts. In addition to investment risks associated with the underlying issuer, depositary receipts may expose a Fund to additional risks associated with non-uniform terms that apply to depositary receipt programs, including credit exposure to the depository bank and to the sponsors and other parties with whom the depository bank establishes the programs, currency, political, economic, market risks and the risks of an illiquid market for depositary receipts. Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. Depositary receipts may not track the price of the underlying foreign securities on which they are based, may have limited voting rights, and may have a distribution subject to a fee charged by the depository. As a result, equity shares of the underlying issuer may trade at a discount or premium to the market price of the depositary receipts. Some institutions issuing depositary receipts may not be sponsored by the issuer. Unsponsored programs generally expose investors to greater risks than sponsored programs and do not provide holders with many of the shareholder benefits that come from investing in a sponsored depositary receipt.

Derivatives Risk. A derivative is a financial instrument whose value is derived from, or based upon, the performance of underlying assets, interest or currency exchange rates, or other indices and may be leveraged. Derivatives include options, total rate of return swaps, currency swaps, equity swaps, interest rate swaps, forward foreign currency exchange contracts and futures contracts, options on

206

Additional Fund Information (cont.)

futures contracts, structured securities such as collateralized mortgage obligations and other types of asset-backed securities, “stripped” securities and various floating rate instruments. The Funds may use these instruments to help them track their respective Underlying Indexes.

An investment in derivatives can be more sensitive to changes in interest rates and sudden fluctuations in market prices than conventional securities. Investments in derivative instruments, which may be leveraged, may result in losses exceeding the amounts invested. A Fund’s losses may be greater if it invests in derivatives than if it invests only in conventional securities. Engaging in derivative transactions involves special risks, including that:

(a) the Fund’s derivatives position will lose value;

(b) the counterparty to the transaction will default;

(d) the Fund will be unable to sell its position because of lack of market depth or disruption;

(e) the value of a derivative instrument will be difficult to determine; and

(f) loss will occur as a result of inadequate systems or human error.

Many types of derivatives have been developed recently and have not been tested over complete market cycles. For these reasons, a Fund may suffer a loss whether or not the analysis of the Investment Adviser is accurate.

Entering into derivatives contracts may cause a Fund to miss favorable trading opportunities, due to a lack of sufficient cash or readily marketable securities, and may also cause a Fund to realize losses on offsetting or terminated derivative contracts or special transactions.

Forward foreign currency contracts. A forward foreign currency exchange contract is an obligation to exchange one currency for another on a future date at a specified exchange rate. There can be no assurance that appropriate foreign currency transactions will be available for the Fund at any time or that a Fund will enter into such transactions at any time or under any circumstances even if appropriate transactions are available to it. Also, such transactions may not be successful and may eliminate any chance for the

Fund to benefit from favorable fluctuations in relevant foreign currencies.

Forward foreign currency contracts are privately negotiated transactions, and can have substantial price volatility. As a result, they offer less protection against default by the other party than is available for instruments traded on an exchange. The institutions that deal in forward foreign currency contracts are not required to continue to make markets in the currencies they trade and these markets can experience periods of illiquidity.

Futures contracts and options on futures contracts. A futures contract is a type of derivative instrument that obligates the holder to buy or sell a specified financial instrument or currency in the future at an agreed upon price. For example, a futures contract may obligate a Fund, at maturity, to take or make delivery of certain domestic or foreign securities, the cash value of a securities index or a stated quantity of a foreign currency. When a Fund purchases an option on a futures contract, it has the right to assume a position as a purchaser or seller of a futures contract at a specified exercise price during the option period. When a Fund sells an option on a futures contract, it becomes obligated to purchase or sell a futures contract if the option is exercised.

Futures contracts and options present the following risks: imperfect correlation between the change in market value of a Fund’s securities and the price of futures contracts and options; the possible inability to close a futures contract when desired; losses due to unanticipated market movements which potentially are unlimited; and the possible inability of the Investment Adviser to correctly predict the direction of securities prices, interest rates, currency exchange rates and other economic factors. Futures markets are highly volatile and the use of futures may increase the volatility of a Fund’s NAV. As a result of the low margin deposits normally required in futures trading, a relatively small price movement in a futures contract may result in substantial losses to a Fund. Futures contracts and options on futures may be illiquid, and exchanges may limit fluctuations in futures contract prices during a single day. Foreign exchanges or boards of trade generally do not offer the same protections as U.S. exchanges.

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Additional Fund Information (cont.)

Swaps. Swap agreements may be structured in different ways. Swaps allow a fund to invest in a market without owning or taking physical custody of securities in circumstances in which direct investment is restricted for legal reasons or is otherwise impracticable. Currency swaps are contracts that obligate a Fund and another party to exchange their rights to pay or receive specified amounts of currency. Total rate of return swaps are contracts that obligate a party to pay or receive interest in exchange for the payment by the other party of the total return generated by a security, a basket of securities, an index or an index component. Interest rate swaps involve the exchange by a Fund with another party of their respective commitments to pay or receive interest, e.g., an exchange of floating rate payments for fixed rate payments with respect to a notional amount of principal. The use of swaps is a highly specialized activity that involves investment techniques and risks different from those associated with ordinary portfolio securities transactions. Like other derivative instruments, swaps can be highly volatile. If the Investment Adviser is incorrect in its forecasts of market values and currency exchange rates, the investment performance of a Fund would be less favorable than it would have been if these instruments were not used. Because these instruments normally are illiquid, a Fund may not be able to terminate its obligations when desired. In addition, if a Fund is obligated to pay the return under the terms of a total rate of return swap, Fund losses due to unanticipated market movements potentially are unlimited. A Fund also may suffer a loss if the other party to a transaction defaults.

Options. Options contracts may relate to particular securities, foreign and domestic stock indexes, financial instruments, foreign currencies or the yield differential between two securities (“yield curve options”) and may or may not be listed on a domestic or foreign securities exchange or issued by the Options Clearing Corporation. A Fund may “cover” a call option by owning the security underlying the option or through other means. Put options written by a Fund are “secured” if the Fund maintains liquid assets in a segregated account in an amount at least equal to the exercise price of the option up until the expiration date.

An option is a type of derivative instrument that gives the holder the right (but not the obligation) to buy (a “call”) or sell (a “put”) on an asset in the future at an agreed upon

price prior to the expiration date of the option. Options trading is a highly specialized activity that involves investment techniques and risks different from those associated with ordinary Fund securities transactions. The value of options can be highly volatile, and their use can result in loss if the investment management team is incorrect in its expectation of price fluctuations.

A Fund will invest and trade in unlisted over-the-counter options only with firms deemed creditworthy by the Investment Adviser. However, unlisted options are not subject to the protections afforded purchasers of listed options by the Options Clearing Corporation, which performs the obligations of its members which fail to perform them in connection with the purchase or sale of options.

Distressed Securities Risk. Distressed securities are speculative and involve substantial risks in addition to the risks of investing in non-investment grade bonds. NTI defines securities issued by companies whose financial condition is troubled or uncertain and that may be involved in bankruptcy proceedings, reorganizations or financial restructurings as “distressed securities.” A Fund investing in distressed securities will generally not receive interest payments on the distressed securities and may incur costs to protect its investment. In addition, distressed securities involve the substantial risk that principal will not be repaid and present a substantial risk of default. The Fund may incur additional expenses to the extent it is required to seek recovery upon a default in the payment of principal of or interest on its portfolio holdings. In any reorganization or liquidation proceeding relating to a portfolio company, the Fund may lose its entire investment or may be required to accept cash or securities with a value less than its original investment. Distressed securities and any securities received in an exchange for such securities may be subject to restrictions on resale.

Typically, such workout or bankruptcy proceedings result in only partial recovery of cash payments or an exchange of the defaulted obligation for other debt or equity securities of the issuer or its affiliates, which may in turn be illiquid or speculative. There is even a potential risk of loss by the Fund of its entire investment in such securities. There are a number of significant risks inherent in the bankruptcy process. A bankruptcy filing by an issuer may adversely and

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Additional Fund Information (cont.)

permanently affect the market position and operations of the issuer. Many factors of the bankruptcy process, including court decisions, the size and priority of other claims, and the duration and costs of the bankruptcy process, are beyond the control of the Fund and can adversely affect the Fund’s return on investment. For example, a court could invalidate or subordinate a debt obligation of, or reclaim amounts paid by a debtor to, the Fund. To the extent that any such payments are recaptured from the Fund, the resulting loss will be borne by the Fund and its investors. NTI, on behalf of the Fund, may also participate on committees formed by creditors to negotiate with debtors with respect to restructuring issues. There can be no assurance that NTI’s participation would yield favorable results for the Fund, and such participation may subject the Fund to additional duties, liabilities and trading restrictions in a particular investment.

Dividend Risk. An issuer of stock held by a Fund may choose not to declare a dividend or the dividend rate might not remain at current levels. Dividend paying stocks might not experience the same level of earnings growth or capital appreciation as non-dividend paying stocks. A Fund’s performance during a broad market advance could suffer because dividend paying stocks may not experience the same capital appreciation as non-dividend paying stocks.

Emerging Markets Risk. The risks of foreign investment are increased when the issuer is located in a country with an emerging economy or securities market. Political and economic structures in many of these countries may be undergoing significant evolution and rapid development, and these countries may lack the social, political and economic stability, and impose more governmental limitations on foreign investments, than more developed countries. The securities laws of emerging market countries may be relatively new and unsettled and, consequently, there is a risk of rapid and unpredictable change in laws regarding foreign investment, securities regulation, title to securities and shareholder rights. Global factors and foreign actions may inhibit the flow of foreign capital on which a country is dependent to sustain its growth. In general, securities markets of emerging countries are less liquid, are especially subject to greater price volatility, have smaller market capitalizations, and have problems with securities registration

and custody. These securities markets also have less government regulation and are not subject to as stringent regulatory, disclosures, accounting, auditing, recordkeeping, financial and other reporting requirements as the securities markets of more developed countries. In addition, because the securities settlement procedures are less developed in these countries, a Fund may be required to deliver securities before receiving payment and also may be unable to complete transactions during market disruptions. As a result of these a Fund’s purchase and sale of portfolio securities in certain emerging countries may be constrained by limitations relating to daily changes in the prices of listed securities, periodic trading or settlement volume and/or limitations on aggregate holdings of foreign investors. Such limitations may be computed based on the aggregate trading volume by or holdings of a Fund, the Investment Adviser, its affiliates and their respective clients and other service providers. A Fund may not be able to sell securities in circumstances where price, trading or settlement volume limitations have been reached.

Foreign investment in the securities markets of certain emerging countries is restricted or controlled to varying degrees which may limit investment in such countries or increase the administrative costs of such investments. For example, certain Asian countries require governmental approval prior to investments by foreign persons or limit investment by foreign persons to only a specified percentage of an issuer’s outstanding securities or a specific class of securities which may have less advantageous terms (including price) than securities of the issuer available for purchase by nationals. In addition, certain countries may restrict or prohibit investment opportunities in issuers or industries deemed important to national interests. Such restrictions may affect the market price, liquidity and rights of securities that may be purchased by a Fund. The repatriation of both investment income and capital from certain emerging countries is subject to restrictions such as the need for governmental consents.

Many emerging countries have recently experienced currency devaluations and substantial (and, in some cases, extremely high) rates of inflation. Other emerging countries have experienced economic recessions. These circumstances have had a negative effect on the economies and securities markets of those emerging countries. Economies

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Additional Fund Information (cont.)

in emerging countries generally are dependent heavily upon commodity prices and international trade and, accordingly, have been and may continue to be affected adversely by the economies of their trading partners, trade barriers, exchange controls, managed adjustments in relative currency values and other protectionist measures imposed or negotiated by the countries with which they trade. Many emerging countries are subject to a substantial degree of economic, political and social instability. Governments of some emerging countries are authoritarian in nature or have been installed or removed as a result of military coups, while governments in other emerging countries have periodically used force to suppress civil dissent. Disparities of wealth, the pace and success of democratization, and ethnic, religious and racial disaffection, among other factors, have also led to social unrest, violence and/or labor unrest in some emerging countries. Unanticipated political or social developments may result in sudden and significant investment losses. Investing in emerging countries involves greater risk of loss due to expropriation, nationalization, confiscation of assets and property or the imposition of restrictions on foreign investments and on repatriation of capital invested. As an example, in the past some Eastern European governments have expropriated substantial amounts of private property, and many claims of the property owners have never been fully settled. There is no assurance that similar expropriations will not recur in Eastern European or other countries. Emerging markets countries also may have less developed legal systems allowing for enforcement of private property rights and/or redress for injuries to private property, such as bankruptcy. The ability to bring and enforce actions in emerging market countries, or to obtain information needed to pursue or enforce such actions, may be limited and shareholder claims may be difficult or impossible to pursue.

A Fund’s investment in emerging countries may also be subject to withholding or other taxes, which may be significant and may reduce the return from an investment in such countries to the Fund.

Settlement and clearance procedures in emerging countries are frequently less developed and reliable than those in the United States and may involve the Fund’s delivery of securities before receipt of payment for their sale. In addition,

significant delays may occur in certain markets in registering the transfer of securities. Settlement, clearance or registration problems may make it more difficult for the Fund to value its portfolio securities and could cause the Fund to miss attractive investment opportunities, to have a portion of its assets uninvested or to incur losses due to the failure of a counterparty to pay for securities the Fund has delivered or the Fund’s inability to complete its contractual obligations because of theft or other reasons. In addition, local agents and depositories are subject to local standards of care that may not be as rigorous as developed countries. Governments and other groups may also require local agents to hold securities in depositories that are not subject to independent verification. The less developed a country’s securities market, the greater the risk to the Funds.

The creditworthiness of the local securities firms used by a Fund in emerging countries may not be as sound as the creditworthiness of firms used in more developed countries. As a result, the Fund may be subject to a greater risk of loss if a securities firm defaults in the performance of its responsibilities.

The small size and inexperience of the securities markets in certain emerging countries and the limited volume of trading in securities in those countries may make the Funds’ investments in such countries less liquid and more volatile than investments in countries with more developed securities markets (such as the United States, Japan and most Western European countries). The Funds’ investments in emerging countries are subject to the risk that the liquidity of a particular investment, or investments generally, in such countries will shrink or disappear suddenly and without warning as a result of adverse economic, market or political conditions or adverse investor perceptions, whether or not accurate. Because of the lack of sufficient market liquidity, a Fund may incur losses because it will be required to effect sales at a disadvantageous time and then only at a substantial drop in price. Investments in emerging countries may be more difficult to price precisely because of the characteristics discussed above and lower trading volumes.

A Fund’s use of foreign currency management techniques in emerging countries may be limited. Due to the limited market for these instruments in emerging countries, all or

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Additional Fund Information (cont.)

a significant portion of the Funds’ currency exposure in emerging countries may not be covered by such instruments.

From time to time, certain of the companies in which a Fund may invest may operate in, or have dealings with, countries subject to sanctions or embargoes imposed by the U.S. government and the United Nations and/or countries identified by the U.S. government as state sponsors of terrorism. A company may suffer damage to its reputation if it is identified as a company which operates in, or has dealings with, countries subject to sanctions or embargoes imposed by the U.S. government and the United Nations and/or countries identified by the U.S. government as state sponsors of terrorism. As an investor in such companies, a Fund will be indirectly subject to those risks.

There is significant uncertainty regarding how recent wars between Russia and Ukraine in Europe and Hamas and Israel in the Middle East will evolve. The resulting market disruptions and volatility are impossible to predict, but could be significant and have an adverse effect on certain Fund investments as well as Fund performance and liquidity.

Equity Securities Risk. Equity securities are subject to changes in value that may be attributable to market perception of a particular issuer, general stock market fluctuations that affect all issuers, or as a result of such factors as a company’s business performance, investor perceptions, stock market trends and general economic conditions. The equity securities owned by a Fund may be more volatile and underperform other asset classes and the general securities markets.

ESG Investment Risk. The Index Provider includes and excludes issuers and assigns weights to issuers in a Fund’s Underlying Index by applying non-financial factors; therefore, a Fund may underperform the broader financial markets or other funds that do or do not use ESG factors, scores, or screens in their securities selection process, or use a different ESG methodology. The ESG methodology of the Underlying Index will affect the Funds’ exposure to certain companies, sectors, regions and countries and may adversely affect the Fund’s performance depending on whether such investments are in or out of favor. Although each Underlying Index is designed to measure a portfolio

of companies with certain ESG characteristics, there is no assurance that every security in an Underlying Index or a Fund will have ESG characteristics or that companies that have historically exhibited such characteristics will continue to exhibit such characteristics. There is also the risk that a Fund may have indirect exposure to companies that have been excluded from the Underlying Index through its use of certain derivative instruments.

Currently, there is a lack of common industry standards relating to the development and application of ESG criteria, which may make it difficult to compare the Funds’ principal investment strategies with the investment strategies of other funds that integrate certain ESG criteria. The subjective value that investors may assign to certain types of ESG characteristics may differ substantially from that of the assessment by the Index Provider or a data provider. Investors can differ in their views of what constitutes positive or negative ESG characteristics. As a result, a Fund may invest in companies that do not reflect the beliefs and values of any particular investor. A company included in the Underlying Index may not exhibit positive or favorable ESG characteristics. The companies selected by the Index Provider as demonstrating certain ESG characteristics may not be the same companies selected by other index providers or investment managers as exhibiting those characteristics.

The Index Provider relies on various sources of information regarding an issuer, including information that may be based on assumptions and estimates. ESG information from third-party data providers may be incomplete, inaccurate or unavailable. Neither the Funds nor NTI can offer assurances that the Underlying Index’s methodology or sources of information will provide an accurate assessment of the issuers of the securities included in a Fund’s Underlying Index. The Index Provider uses third-party data that it believes to be reliable, but it does not guarantee the accuracy of such third-party data. Data can vary across providers or within industries. ESG standards differ by region and industry, and a company’s ESG practices or the Index Provider’s or data providers’ assessment of a company’s ESG practices may change over time. Regulatory changes or interpretations regarding the definitions and/or use of ESG criteria could have a material adverse effect on a Fund's

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ability to invest in accordance with its investment policies and/or achieve its investment objective.

Foreign Securities Risk. Foreign securities fluctuate in price because of political, financial, social, environmental and economic events in foreign countries (including, for example, military confrontations, war and terrorism). In addition, foreign securities may lose value and a Fund may be adversely impacted by restrictions placed on U.S. investors by U.S. regulations governing foreign investments. Foreign securities also could lose value because of more or less stringent foreign securities regulations and less stringent accounting and disclosure standards. In addition, foreign markets may have greater volatility than domestic markets and foreign securities may be less liquid and harder to value than domestic securities. Foreign securities are sensitive to changes in interest rates.

Foreign securities are sensitive to changes in interest rates. The performance of investments in securities denominated in a foreign currency also will depend, in part, on the strength of the foreign currency against the U.S. dollar and the interest rate environment in the country issuing the currency. Absent other events that otherwise could affect the value of a foreign security (such as a change in the political climate or an issuer’s credit quality), appreciation in the value of the foreign currency generally results in an increase in value of a foreign currency-denominated security in terms of U.S. dollars. A decline in the value of the foreign currency relative to the U.S. dollar generally results in a decrease in value of a foreign currency-denominated security. Additionally, many countries throughout the world are dependent on a healthy U.S. economy and are adversely affected when the U.S. economy weakens or its markets decline. For example, the decline in the U.S. subprime mortgage market quickly spread throughout global credit markets, triggering a liquidity crisis that affected fixed-income and equity markets around the world.

Investment in foreign securities may involve higher costs than investment in U.S. securities, including higher transaction and custody costs as well as the imposition of additional taxes by foreign governments. Foreign investments also may involve risks associated with the level of currency exchange rates, less complete financial information about the issuers, less market liquidity and more market volatility

and political instability. Future political and economic developments, the possible imposition of withholding taxes on dividend income, the possible seizure or nationalization of foreign holdings, the possible establishment of exchange controls or freezes on the convertibility of currency, trade restrictions (including tariffs), or the adoption of other governmental restrictions might adversely affect an investment in foreign securities. Additionally, foreign banks and foreign branches of domestic banks may be subject to less stringent reserve requirements and to different accounting, auditing and recordkeeping requirements.

To the extent that the underlying securities and/or other assets held by a Fund trade on foreign exchanges or in foreign markets that may be closed when the securities exchange on which the Fund’s shares trade is open, there are likely to be deviations between the current price of an underlying security and the last quoted price for the underlying security (i.e., a Fund’s quote from the closed foreign market). The impact of a closed foreign market on the Fund is likely to be greater where a large portion of the Fund’s underlying securities and/or other assets trade on that closed foreign market or when the foreign market is closed for unscheduled reasons. These deviations could result in premiums or discounts to the Fund’s NAV that may be greater than those experienced by other ETFs.

Fund of Funds Risk. The FlexShares® Real Assets Allocation Index Fund invests a substantial portion of its assets in its Underlying Funds, so the Fund’s investment performance is directly related to the performance of its Underlying Funds. The Fund may also invest in other funds, including money market funds. The Fund’s NAV will change with changes in the value of its Underlying Funds and other securities in which the Fund may invest based on its market valuation. In addition, the shares of the Underlying Funds may trade at a premium or discount to their intrinsic value (i.e., the market value may differ from the NAV of an ETF’s shares) for a number of reasons. For example, supply and demand for shares of an Underlying Fund or market disruptions may cause the market price of the Underlying Fund to deviate from the value of the Underlying Fund’s investments, which may be exacerbated in less liquid markets. An investment in the Fund will entail more direct and indirect costs and expenses than a direct investment in its Underlying Funds. For example, the Fund

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indirectly pays a portion of the expenses (including operating expenses and management fees) incurred by its Underlying Funds.

An investor in the Fund may receive taxable gains from portfolio transactions by the Underlying Funds, as well as taxable gains from transactions in shares of the Underlying Funds held by the Fund.

As the Fund’s allocations to its Underlying Funds change from time to time, or to the extent that the expense ratio of the Underlying Funds changes, the weighted average operating expenses borne by the Fund may increase or decrease.

Geographic Risk If a fund invests a significant portion of its total assets in certain issuers within the same country or geographic region, an economic, business or political development affecting that country or region may affect the value of the fund’s investments more than if the fund’s investments were not so concentrated in such country or region.

•China Investment Risk. Investment exposure to China subjects a Fund to risks specific to China. China may be subject to considerable degrees of economic, political and social instability. China is a developing market and demonstrates significantly higher volatility from time to time in comparison to developed markets. Over the past 25 years, the Chinese government has undertaken reform of economic and market practices and expansion of the sphere for private ownership of property in China. However, Chinese markets generally continue to experience inefficiency, volatility and pricing anomalies resulting from governmental influence, a lack of publicly available information and/or political and social instability. Internal social unrest or confrontations with other neighboring countries, including military conflicts in response to such events, may also disrupt economic development in China and result in a greater risk of currency fluctuations, currency convertibility, interest rate fluctuations and higher rates of inflation. Export growth continues to be a major driver of China’s rapid economic growth. Reduction in spending on Chinese products and services, institution of tariffs or other trade barriers, or a

downturn in any of the economies of China’s key trading partners may have an adverse impact on the Chinese economy. In addition, China has experienced outbreaks of infectious illnesses, and the country may be subject to other public health threats, infectious illnesses, diseases or similar issues in the future. These or similar outbreaks could reduce consumer demand or economic output, result in market closures, travel restrictions or quarantines, and generally have a significant impact on the Chinese economy, which in turn could adversely affect the Fund’s investments. In addition, trade relations between the U.S. and China have recently been strained. Worsening trade relations between the two countries could adversely impact the Fund, particularly to the extent that the Chinese government restricts foreign investments in on-shore Chinese companies or the U.S. government restricts investments by U.S. investors in China. Worsening trade relations may also result in market volatility and volatility in the price of Fund shares.

Additionally, Chinese companies are required to follow Chinese accounting standards and practices, which only follow international accounting standards to a certain extent. However, the accounting, auditing and financial reporting standards and practices applicable to Chinese companies may be less rigorous, and there may be significant differences between financial statements prepared in accordance with Chinese accounting standards and those prepared in accordance with international accounting standards. In particular, the assets and profits appearing on the financial statements of a Chinese issuer may not reflect its financial position or results of operations in the way they would be reflected had such statements been prepared in accordance with U.S. Generally Accepted Accounting Principles. Consequently, the quality of audits in China may be unreliable, which may require enhanced procedures. Consequently, the Fund may not be provided with the same level of protection or information as would generally apply in developed countries, and a Fund may be exposed to significant losses.

In addition, there may be restrictions on investments in Chinese companies. For example, on November 12, 2020, the President of the United States of America

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signed an Executive Order prohibiting U.S. persons from purchasing or investing in publicly-traded securities of companies identified by the U.S. government as “Communist Chinese military companies.” The list of such companies can change from time to time. Certain securities impacted by the Executive Order (“Prohibited Securities”) have been, or will be, removed from a Fund’s portfolio, as applicable.

Certain Prohibited Securities may have less liquidity and the market price of such Prohibited Securities may decline and a Fund may incur a loss as a result. In addition, the market for securities of other Chinese-based issuers may also be negatively impacted resulting in reduced liquidity and price declines.

Additionally, certain Prohibited Securities that have been, or will be, sold by a Fund may not be immediately removed from the Fund’s corresponding Underlying Index. This difference between a Fund’s portfolio and its Index constituents could result in tracking error and a greater difference between the Fund’s performance and the performance of the Underlying Index for any period during which a Prohibited Security remains in a Fund’s Underlying Index.

•Japan Investment Risk. The Japanese economy may be subject to considerable degrees of economic, political and social instability, which could negatively impact Japanese issuers. In recent times, Japan’s economic growth rate has remained low, lagging that of its Asian neighbors and other major developed economies, and it may remain low in the future. The Japanese economy is heavily dependent on international trade and has been adversely affected by trade tariffs, other protectionist measures, competition from emerging economies and the economic conditions of its trading partners. Japan’s relations with its neighbors, particularly China, North Korea, South Korea and Russia, have at times been strained due to territorial disputes, historical animosities and defense concerns. Most recently, the Japanese government has shown concern over the increased nuclear and military activity by North Korea. Strained relations may cause uncertainty in the Japanese markets and adversely affect the overall Japanese economy in times of crisis. China has become

an important trading partner with Japan, yet the countries’ political relationship has become strained. Should political tension increase, it could adversely affect the economy, especially the export sector, and destabilize the region as a whole. In addition, Japan is located in a part of the world that has historically been prone to natural disasters such as earthquakes, volcanic eruptions, typhoons and tsunamis, and is economically sensitive to environmental events. Any such event may negatively affect the securities of Japanese companies held by a Fund.

•South Korea Investment Risk. Investments in South Korean issuers involve risks that are specific to South Korea, including legal, regulatory, political, currency, security and economic risks. Substantial political tensions exist between North Korea and South Korea. Escalated tensions involving the two nations and the outbreak of hostilities between the two nations, or even the threat of an outbreak of hostilities, may have a severe adverse effect on the South Korean economy. In addition, South Korea’s economic growth potential has recently been on a decline because of a rapidly aging population and structural problems, among other factors. The South Korean economy is heavily reliant on trading exports, and disruptions or decreases in trade activity could lead to further declines. The South Korean economy’s dependence on the economies of Asia and the U.S. means that a reduction in spending by these economies on South Korean products and services, or negative changes in any of these economies, may cause an adverse impact on the South Korean economy and, therefore, on a Fund’s investments. In addition, South Korea is located in a part of the world that has historically been prone to natural disasters such as earthquakes, hurricanes and tsunamis, and is economically sensitive to environmental events. Any such event may negatively affect the securities of South Korean companies held by a Fund.

•Taiwan Investment Risk. Taiwan’s geographic proximity and history of political contention with China have resulted in ongoing tensions between the two countries. These tensions may materially affect the Taiwanese economy and its securities market. Taiwan’s

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economy is export-oriented, so reductions in spending on Taiwanese products and services, labor shortages, institution of tariffs or other trade barriers, or a downturn in any of the economies of Taiwan’s key trading partners, including the United States, may have an adverse impact on the Taiwanese economy and the values of Taiwanese companies. In addition, rising labor costs and increasing environmental consciousness have led some labor-intensive industries to relocate to countries with cheaper work forces, and continued labor outsourcing may adversely affect the Taiwanese economy. Taiwan’s economy is also intricately linked with the economies of other Asian countries. As a result, political and social unrest in these other Asian countries could cause further economic and market uncertainty in Taiwan. Further, Taiwan is a small island state with few raw material resources and limited land area; therefore, it relies heavily on imports for its commodity needs. Any fluctuations or shortages in the commodity markets could have a negative impact on the Taiwanese economy.

•United Kingdom Investment Risk. Investments in issuers located in the United Kingdom (“UK”) may subject a Fund to regulatory, political, currency, security and economic risk specific to the UK. The UK has one of the largest economies in Europe and is heavily dependent on trade with the European Union (“EU”), and to a lesser extent the United States and China. As a result, the UK economy may be impacted by changes to the economic health of EU member countries, the United States and China. In 2016, the UK voted to leave the EU (commonly known as “Brexit”). On January 31, 2020, the UK officially withdrew from the EU and the UK entered a transition period which ended on December 31, 2020. On December 30, 2020, the EU and UK signed the EU-UK Trade and Cooperation Agreement (“TCA”), which is an agreement on the terms governing certain aspects of the EU’s and the UK’s relationship following the end of the transition period. Notwithstanding the TCA, following the transition period, there is likely to be considerable uncertainty as to the UK’s post-transition framework. The precise impact on the UK’s economy as a result of its departure from the EU depends to a large degree on its

ability to conclude favorable trade deals with the EU and other countries, including the United States, China, India and Japan. While new trade deals may boost economic growth, such growth may not be able to offset the increased costs of trade with the EU resulting from the UK’s loss of its membership in the EU single market. Certain sectors within the UK’s economy may be particularly affected by Brexit, including the automotive, chemicals, financial services and professional services.

High Portfolio Turnover Risk. A high portfolio turnover rate is likely to involve higher brokerage commissions and other transaction costs, which could reduce a Fund’s return. It also may result in the realization and/or distribution to shareholders of higher capital gains or losses as compared to a Fund with less active trading policies.

High Yield Securities Risk. Non-investment grade fixed-income securities, sometimes known as “junk bonds,” will be subject to greater credit risk, price volatility and risk of loss than investment grade securities, which can adversely impact the Funds’ return and NAV. High yield securities are considered highly speculative and are subject to the increased risk of an issuer’s inability to make principal and interest payments.

The market value of these low-rated securities tends to be more sensitive to individual corporate developments and changes in interest rates and economic conditions than higher-rated securities. In addition, they generally present a higher degree of credit risk. Issuers of low-rated securities are often highly leveraged, so their ability to repay their debt during an economic downturn or periods of rising interest rates may be impaired. The risk of loss due to default by these issuers also is greater because low-rated securities generally are unsecured and often are subordinated to the rights of other creditors of the issuers of such securities. Investments by the Funds in defaulted securities pose additional risk of loss should non-payment of principal and interest continue in respect of such securities. Even if such securities are held to maturity, recovery by the Funds of its initial investment and any anticipated income or appreciation will be uncertain. The Funds also may incur additional expenses in seeking recovery on defaulted securities.

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The secondary market for lower quality securities is concentrated in relatively few market makers and is dominated by institutional investors. Accordingly, the secondary market for such securities is not as liquid as, and is more volatile than, the secondary market for higher quality securities. In addition, market trading volume for these securities generally is lower and the secondary market for such securities could contract under adverse market or economic conditions, independent of any specific adverse changes in the condition of a particular issuer. These factors may have an adverse effect on the market price and the Funds’ ability to dispose of particular portfolio investments. A less developed secondary market also may make it more difficult for the Funds to obtain precise valuations of such securities in its portfolio.

Income Risk. A Fund’s income may decline when interest rates fall. This decline can occur because a Fund must invest in lower-yielding bonds as bonds in its portfolio mature, bonds in each Fund’s respective Underlying Index are substituted, or a Fund otherwise needs to purchase additional bonds. The Index Provider’s substitution of bonds in a Fund’s Underlying Index may occur, for example, when the time to maturity for the bond no longer matches the Underlying Index’s stated maturity guidelines.

If a Fund invests in Treasury Inflation-Protected Securities (“TIPS”), the Fund’s income may decline due to a decline in inflation (or deflation). If there is deflation, the principal value of inflation-linked securities, such as TIPS, will be adjusted downward, and consequently the interest payments (calculated with respect to a smaller principal amount) will be reduced. If inflation is lower than expected during the period a Fund holds TIPS, the Fund may earn less income on the security than on a conventional bond.

Index Risk. Because the Funds are not actively managed, a Fund would not necessarily buy or sell a security unless that security is added or removed, respectively, from its Underlying Index, even if that security generally is underperforming, because unlike many investment companies, the Funds do not utilize an investing strategy that seeks returns in excess of an index. Additionally, each Fund rebalances and/or reconstitutes its portfolio in accordance with its Underlying Index, and, therefore, any changes to the Underlying Index’s rebalance and/or reconstitution

schedule will result in corresponding changes to the Fund’s rebalance and/or reconstitution schedule.

Inflation-Protected Securities Risk. The value of inflation-indexed debt securities are subject to the effects of changes in real interest rates that may change as a result of different factors. In general, the value of an inflation-indexed security, including TIPS, tends to decrease when real interest rates increase and increase when real interest rates decrease. Interest payments on inflation-indexed securities will vary along with changes in the Consumer Price Index for All Urban Consumers (CPI-U) before seasonal adjustment (calculated by the Bureau of Labor Statistics). Thus generally, during periods of rising inflation, the value of inflation-indexed securities will tend to increase and during periods of deflation, their value will tend to decrease. There can be no assurance that the inflation index used (i.e., CPI-U) will accurately measure the price increase of a certain good or service. Increases in the principal value of TIPS due to inflation are considered taxable ordinary income for the amount of the increase in a calendar year.

Interest Rate Risk. Increases in interest rates typically lower the present value of a REIT’s future earnings stream, and may make financing property purchases and improvements more costly. Because the market price of REIT stocks may change based upon investors’ collective perceptions of future earnings, the value of a Fund may decline when investors anticipate or experience rising interest rates.

Interest Rate/Maturity Risk. Generally, when interest rates rise, prices of fixed-income securities fall. However, market factors, such as the demand for particular fixed-income securities, may cause the price of certain fixed-income securities to fall while the prices of other securities rise or remain unchanged. A fixed-income security’s duration approximates its price sensitivity to changes in interest rates. For example, suppose that interest rates in one day fall by one percent which, in turn, causes yields on every bond in the market to fall by the same amount. In this example, the price of a bond with a duration of three years may be expected to rise approximately three percent and the price of a bond with a five-year duration may be expected to rise approximately five percent. The converse is

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also true. Suppose interest rates in one day rise by one percent which, in turn, causes yields on every bond in the market to rise by the same amount. In this second example, the price of a bond with a duration of three years may be expected to fall approximately three percent and the price of a bond with a five-year duration may be expected to fall approximately five percent. Interest rate changes have a greater effect on the price of fixed-income securities with longer durations. Certain factors, such as the presence of call features, may cause a particular fixed-income security, or a Fund as a whole, to exhibit less sensitivity to changes in interest rates. The maturity of a security, another commonly used measure of price sensitivity, measures only the time until final payment is due, whereas duration takes into account the pattern of all payments of interest and principal on a security over time, including how these payments are affected by prepayments and by changes in interest rates.

A wide variety of factors can cause interest rates to rise (e.g., central bank monetary policies, inflation rates, general economic conditions, etc.). An increase in interest rates may lead to heightened volatility in the fixed-income markets and may adversely affect the liquidity of certain fixed-income investments.

Liquidity Risk. To the extent a Fund invests in illiquid investments or investments that become illiquid, such investments may have a negative effect on the returns of the Fund because the Fund may be unable to sell the illiquid investments at an advantageous time or price. Liquid investments may become illiquid after purchase by a Fund, particularly during periods of market turmoil. Illiquid investments may be harder to value, especially in changing markets, and if a Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. Liquidity risk may result from the lack of an active market, reduced number and capacity of traditional market participants to make a market in fixed income securities, or a redemption request by a large shareholder (such as a seed investor), and may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. Additionally, the market for certain investments may become illiquid under adverse

market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. In such cases, a Fund, due to limitations on investments in illiquid investments and/or purchasing and selling such investments, may be unable to achieve a high degree of correlation with the Fund’s Underlying Index. Additionally, in adverse market conditions, a Fund’s market price may begin to reflect illiquidity or pricing uncertainty of a Fund’s portfolio securities. This could lead to the Fund’s shares trading at a price that is higher or lower than the Fund’s NAV. At times, such differences may be significant.

Low Volatility Risk. There is no guarantee that an Underlying Index that is designed to have overall volatility that is lower than that of its Parent Index will be successful. Securities or other assets in the portfolios of the FlexShares® US Quality Low Volatility Index Fund, FlexShares® Developed Markets ex-US Quality Low Volatility Index Fund and FlexShares® Emerging Markets Quality Low Volatility Index Fund may be subject to price volatility and the prices may not be any less volatile than the market as a whole and could be more volatile. Events or financial circumstances affecting individual securities or sectors may increase the volatility of a Fund. The price of a security may fluctuate due to factors affecting markets generally or particular industries. The market prices of the securities or other assets in a Fund’s portfolio may fluctuate, sometimes rapidly and unpredictably. A Fund will continue to seek to track the Underlying Index even if the Underlying Index does not have lower overall volatility than the Parent Index. There is also the risk that a Fund may experience volatility greater than that of its Parent Index as a result of tracking error. A portfolio of securities with greater volatility is generally considered to have a higher risk profile than a portfolio with lower volatility.

Market Risk. The value of a Fund’s investments may increase or decrease in response to expected real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by a Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, changes in interest rates, lack of liquidity in the bond or equity markets, volatility in the equities market or

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adverse investor sentiment. Local, regional or global events such as financial institution failures, war, acts of terrorism, the spread of infectious illness or other public health issues, recessions, or other events or adverse investor sentiment or other political, regulatory, economic and social developments, and developments that impact specific economic sectors, industries or segments of the market or other events could have a significant impact on a Fund and its investments and could result in a Fund’s shares trading at increased premiums or discounts to the Fund’s NAV. These risks may be magnified if certain events or developments adversely interrupt the global supply chain. Market risk includes the risk that a particular style of investing, such as growth or value, may underperform the market generally. The value of the securities in which a Fund invests may go up or down in response to the prospects of individual issuers and/or general economic conditions. Securities markets may experience great short-term volatility and may fall sharply at times. Different markets may behave differently from each other and a foreign market may move in the opposite direction from the U.S. market. Price changes may be temporary or last for extended periods. You could lose money over short periods due to fluctuation in the market prices of a Fund’s shares in response to market movements, and over longer periods during market downturns.

Periods of unusually high financial market volatility and restrictive credit conditions, at times limited to a particular sector or geographic area, have occurred in the past and may be expected to recur in the future. Some countries, including the United States, have adopted or have signaled protectionist trade measures, relaxation of the financial industry regulations that followed the financial crisis, and/or reductions to corporate taxes. The scope of these policy changes is still developing, but the equity and debt markets may react strongly to expectations of change, which could increase volatility, particularly if a resulting policy runs counter to the market’s expectations. The outcome of such changes cannot be foreseen at the present time. In addition, geopolitical and other risks, including environmental and public health risks, may add to instability in the world economy and markets generally. As a result of increasingly interconnected global economies and financial markets, the value and liquidity of a Fund’s investments may be negatively affected by events impacting a

country or region, regardless of whether the Fund invests in issuers located in or with significant exposure to such country or region.

An outbreak of respiratory disease caused by a novel coronavirus was first detected in December 2019 and has spread internationally. The outbreak and efforts to contain its spread have resulted at times in closing borders and quarantines, restricting international and domestic travel, enhanced health screenings, cancellations, disrupted supply chains and customer activity, responses by businesses (including changes to operations and reducing staff), and have produced general concern and uncertainty. The impact of the coronavirus pandemic, and other epidemics and pandemics that may arise in the future, could adversely affect national and global economies, individual companies and the market in general in a manner and for a period of time that cannot be foreseen at the present time. Health crises caused by the recent outbreak may heighten other preexisting political, social and economic risks in a country or region. Governmental authorities and regulators throughout the world, such as the U.S. Federal Reserve, have in the past responded to major economic disruptions with changes to fiscal and monetary policy, including but not limited to, direct capital infusions, new monetary programs, and dramatically lower interest rates. Certain of those policy changes are being implemented or considered in response to the coronavirus outbreak. Such policy changes may adversely affect the value, volatility and liquidity of dividend and interest paying securities. In certain cases, an exchange or market may close or issue trading halts on either specific securities or even the entire market, which may result in a Fund being, among other things, unable to buy or sell certain securities or financial instruments or to accurately price its investments. In the event of a pandemic or an outbreak, there can be no assurance that the Funds and their service providers will be able to maintain normal business operations for an extended period of time or will not lose the services of key personnel on a temporary or long-term basis due to illness or other reasons. A pandemic or disease could also impair the information technology and other operational systems upon which the Investment Adviser relies, and could otherwise disrupt the ability of the Fund’s service providers to perform essential tasks. Although multiple asset classes may be

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affected by a market disruption, the duration and effects may not be the same for all types of assets. To the extent a Fund may overweight its investments in certain countries, companies, industries or market sectors, such position will increase a Fund’s exposure to risk of loss from adverse developments affecting those countries, companies, industries or sectors. These conditions could result in a Fund’s inability to achieve its investment objectives, cause the postponement of reconstitution or rebalance dates for a Fund’s underlying index or benchmark index, adversely affect the prices and liquidity of the securities and other instruments in which a Fund invests, negatively impact a Fund’s performance, and cause losses on your investment in a Fund. During periods of market disruption or other abnormal market conditions, a Fund’s exposure to the risks described elsewhere in this Prospectus will likely increase. Market disruptions, regulatory restrictions or other abnormal market conditions could have an adverse effect on a Fund’s ability to adjust its exposure to the required levels in order to track its Underlying Index or cause delays in the Underlying Index’s rebalancing or rebalancing schedule. During any such delay, it is possible that the Underlying Index and, in turn, the Fund will deviate from the Underlying Index’s stated methodology and therefore experience returns different than those that would have been achieved under a normal rebalancing or reconstitution schedule. Because each Fund is designed to maintain a high level of exposure to its Underlying Index at all times, it will not take any steps to invest defensively or otherwise reduce the risk of loss during market downturns.

Market Trading Risks

Absence of Active Market

Although the shares of the Funds described in this Prospectus are listed for trading on a listing exchange and may be listed on certain foreign exchanges, there can be no assurance that an active trading market for such shares will be developed or maintained.

Lack of Market Liquidity

Secondary market trading in Fund shares may be halted by a listing exchange because of market conditions or for other reasons. In addition, trading in Fund shares is subject to trading halts caused by extraordinary market volatility

pursuant to “circuit breaker” rules. There can be no assurance that the requirements necessary to maintain the listing of the shares of a Fund will continue to be met or will remain unchanged.

Shares of the Funds May Trade at Prices Other Than NAV

Shares of the Funds may trade at, above or below their most recent NAV. The per share NAV of each Fund is calculated at the end of each business day and fluctuates with changes in the market value of such Fund’s holdings since the prior most recent calculation. The trading prices of a Fund’s shares will generally fluctuate in accordance with changes in its NAV, changes in the relative supply of, and demand for, Fund shares, and changes in the liquidity, or the perceived liquidity, of a Fund’s holdings. The trading prices of a Fund’s shares may deviate significantly from NAV during periods of market volatility. These factors, among others, may lead to a Fund’s shares trading at a premium or discount to NAV. While the creation/redemption feature is designed to make it likely that a Fund’s shares normally will trade close to the Fund’s NAV, exchange prices are not expected to correlate exactly with a Fund’s NAV due to timing reasons as well as market supply and demand factors. In addition, disruptions to creations and redemptions including disruptions at market makers, Authorized Participants, or market participants or during periods of significant volatility, may result in trading prices that differ significantly from NAV. For example, during a “flash crash,” the market prices of a Fund's shares may decline suddenly and significantly. Such a decline may not reflect the performance of the portfolio securities held by the Fund. Flash crashes may cause Authorized Participants and other market makers to limit or cease trading in Fund shares for temporary or longer periods. Shareholders could suffer significant losses to the extent that they sell Fund shares at these temporarily low market prices. If a shareholder purchases at a time when the market price of a Fund is at a premium to its NAV or sells at a time when the market price is at a discount to the NAV, the shareholder may sustain losses that are in addition to any losses caused by a decrease in NAV.

Since foreign exchanges may be open on days when certain Funds do not price their shares, the value of the securities

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Additional Fund Information (cont.)

in these Funds’ portfolios may change on days when shareholders will not be able to purchase or sell the Funds’ shares.

Secondary Market Trading Risk

A Fund may experience low trading volume and wide bid/ask spreads. Bid/ask spreads vary over time based on trading volume and market liquidity (including for the underlying securities held by the Fund), and are generally lower if shares of a Fund have more trading volume and market liquidity and higher if shares of the Fund have little trading volume and market liquidity. In stressed market conditions, the market for a Fund’s shares may become less liquid in response to declining liquidity in the markets for the Fund’s portfolio holdings, which may cause a variance in the market price of the Fund’s shares and their underlying value.

Mid and Small Cap Stock Risk. Stock prices of smaller companies may be more volatile than those of larger companies and therefore the share price of a Fund that invests mostly in smaller companies may be more volatile than those of funds that invest a larger percentage of their assets in stocks issued by large-capitalization companies. Stock prices of smaller companies are generally more vulnerable than those of large-capitalization companies to adverse business and economic developments. The stocks of smaller companies may be thinly traded. In addition, smaller companies are typically less stable financially than larger, more established companies and may depend on a small number of essential personnel, making them more vulnerable to loss of personnel. Smaller companies also normally have less diverse product lines than large-capitalization companies and are more susceptible to adverse developments concerning their products.

MLP Risk. An MLP is a publicly traded company organized as a limited partnership or limited liability company and treated as a partnership for federal income tax purposes. MLPs may derive income and gains from the exploration, development, mining or production, processing, refining, transportation or storage (including pipelines transporting gas, oil, or products thereof), or the marketing of any mineral or natural resources. MLPs generally have two classes of owners, the general partner and limited partners. The general partner of an MLP is typically owned by one or

more of the following: a major energy company, an investment fund, or the direct management of the MLP. The general partner may be structured as a private or publicly traded corporation or other entity. The general partner typically controls the operations and management of the MLP through an up to 2% equity interest in the MLP plus, in many cases, ownership of common units and subordinated units. Limited partners own the remainder of the partnership, through ownership of common units, and have a limited role in the partnership’s operations and management.

As compared to common stockholders of a corporation, holders of MLP units have more limited control and limited rights to vote on matters affecting the partnership and the potential for a conflict of interest exists between common unit holders and a particular MLP’s limited partners. In addition, there are certain tax risks associated with an investment in MLP units and conflicts of interest may exist between common unit holders and the general partner, including those arising from incentive distribution payments. MLPs may also be sensitive to changes in interest rates and during periods of interest rate volatility, may not provide attractive returns.

MLP Tax Risk. A change in current tax law, or a change in the business of a given MLP, could result in an MLP being treated as a corporation for U.S. federal income tax purposes, which would result in such MLP being required to pay U.S. federal income tax on its taxable income. Thus, if any of the MLPs owned by the Fund were treated as corporations for U.S. federal income tax purposes, the after-tax return to the Fund with respect to its investment in such MLPs would be materially reduced. This could cause a decline in the value of the MLPs’ units, and potentially have an adverse effect on the Fund.

To the extent that the Fund invests in the equity securities of an MLP, the Fund will be a limited partner or member in such MLP. Accordingly, the Fund will be required to include in its taxable income the Fund’s allocable share of the income, gains, losses, deductions and expenses recognized by each such MLP, regardless of whether the MLP distributes cash to the Fund. The Fund may have to sell investments to provide cash to make required distributions if its allocable share of an MLP’s income and gains is not

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offset by the MLP’s tax deductions, losses and credits and the MLP does not distribute sufficient cash. The portion, if any, of a distribution received by the Fund from an MLP that is offset by the MLP’s tax deductions, losses or credits is essentially treated as a return of capital. The percentage of an MLP’s income and gains that is offset by tax deductions, losses and credits will fluctuate over time for various reasons. A significant slowdown in acquisition activity or capital spending by MLPs in which the Fund invests could result in a reduction of depreciation deductions, which may result in increased current taxable income for the Fund.

Because of the Fund’s investments in equity securities of MLPs, the Fund’s earnings and profits may be calculated using accounting methods that are different from those used for calculating taxable income. Because of these differences, the Fund may make distributions out of its current or accumulated earnings and profits, which will be treated as taxable dividends, even in years in which the Fund’s distributions exceed its taxable income. In addition, changes in tax laws or regulations, or future interpretations of such laws or regulations, could adversely affect the Fund or the MLP investments in which the Fund invests.

Model Risk. The allocation model utilized in the FlexShares® Real Assets Allocation Index Fund’s securities selection process may not result in improved issuer creditworthiness, maximize returns or minimize risk, or be appropriate for every investor seeking a particular risk profile.

Momentum Risk. Securities that have had higher recent price performance compared to other securities may be more volatile than a broad cross-section of securities or that returns on securities that have previously exhibited price momentum are less than returns on other securities or the overall stock market. Momentum can turn quickly and cause significant variation from other types of investments. An Underlying Fund may follow an index that selects constituent securities based on a “momentum” factor.

Mortgage-Backed Pass-Through Securities Risk. While securities issued by Ginnie Mae are backed by the full faith and credit of the U.S. government, securities issued by Fannie Mae and Freddie Mac are not backed by the full faith

and credit of the U.S. government, and there can be no assurance that the U.S. government would provide financial support to its agencies or instrumentalities where it is not obligated to do so.

Mortgage-backed securities represent interests in “pools” of mortgages. In addition to credit and market risk, these securities may involve prepayment risk because the underlying assets (loans) may be prepaid at any time. Prepayment (or call) risk is the risk that an issuer will exercise its right to pay principal on an obligation held by a Fund (such as a mortgage-backed security) earlier than expected. This may happen during a period of declining interest rates. Under these circumstances, the Fund may be unable to recoup all of its initial investment and will suffer from having to reinvest in lower yielding securities. The loss of higher yielding securities and the reinvestment at lower interest rates can reduce the Fund’s income, total return and share price.

Mortgage-backed securities are also subject to debt extension risk, which is the risk that when interest rates rise, certain mortgage-backed securities will be paid off substantially more slowly than originally anticipated and the value of those securities may fall sharply, resulting in a decline to the Fund’s income and potentially in the value of the Fund’s investments.

Because of call and debt extension risk, mortgage-backed securities react differently to changes in interest rates than other bonds. Small movements in interest rates (both increases and decreases) may quickly and significantly reduce the value of certain mortgage-backed securities. These securities are also subject to the risk of default on the underlying mortgage, particularly during periods of economic downturn.

A Fund seeks to obtain exposure to mortgage-backed securities, as represented in the Underlying Index, primarily through TBA Transactions. Default or bankruptcy of a counterparty to a TBA Transaction would expose the Fund to possible loss because of adverse market action, expenses or delays in connection with the purchase or sale of the mortgage-backed securities specified in the TBA Transaction. The Fund may acquire interests in mortgage pools through means other than such standardized contracts for future delivery.

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New Fund Risk. A Fund may not grow to or maintain an economically viable size, in which case it may experience greater tracking error to its Underlying Index than it otherwise would at higher asset levels, or it could ultimately liquidate without shareholder approval. The timing of such liquidation may not be favorable and could have negative tax consequences for shareholders. From time to time, an Authorized Participant, a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, may invest in the Fund and hold its investment for a specific period of time in order to facilitate commencement of the Fund’s operations or for the Fund to achieve size or scale. There can be no assurance that any such entity would not redeem its investment or that the size of the Fund would be maintained at such levels, which could negatively impact the Fund. The Fund’s distributor does not maintain a secondary market in the shares.

Non-Diversification Risk. A non-diversified fund may invest a larger portion of its assets in securities issued by or representing a smaller number of issuers than a diversified fund. As a result, a Fund may be more susceptible to the risks associated with these particular issuers, or to a single economic, political or regulatory occurrence affecting these issuers.

Prepayment (or Call) Risk. The issuer of a security held by the Funds (such as a mortgage-related or other asset-backed security) may under certain circumstances make principal payments on such security sooner than expected. This may occur, for example, when interest rates decline. Such sooner-than-expected principal payments may reduce the returns of a Fund because the Fund is forced to forego expected future interest payments on the principal amount paid back early and the Fund may be forced to reinvest the money it receives from such early payments at the lower prevailing interest rates.

Quality Factor Risk. The quality factor used in the underlying indexes sponsored by NTI, as the Index Provider, is a quantitative ranking based on: (a) management efficiency (b) profitability; and (c) cash flow. This style of investing is subject to the risk that the past performance of quality companies does not continue or that the returns on equity securities issued by these companies are less than returns on other styles of investing or the overall stock market. In

addition, there may be periods when quality investing is out of favor and during which the investment performance of a fund using a quality strategy may suffer.

Quality-Value Score Risk. The Underlying Indexes for certain Funds are designed to optimize exposure to a combined quality and value score, determined by NTI, as the Index Provider. There is the risk that the Fund’s investment in companies whose securities are believed to be undervalued will not appreciate in value as anticipated or that the past performance of companies that have exhibited quality characteristics does not continue. Although the Underlying Index is designed to measure a portfolio of bonds that can potentially deliver a higher total return relative to the Parent Index, there is no assurance that the Underlying Index or Fund will be comprised of such securities. Accordingly, the Fund may be subject to greater credit risk, price volatility and risk of loss relative to the Parent Index.

Real Estate Securities Risk. The performance of real estate securities may be significantly impacted by the performance of real estate markets. Property values may fall due to increasing vacancies or declining rents resulting from economic, legal, cultural or technological developments. The price of real estate company shares also may drop because of the failure of borrowers to pay their loans and poor management. Many real estate companies utilize leverage, which increases investment risk and could adversely affect a company’s operations and market value in periods of rising interest rates as well as risks normally associated with debt financing. Real property investments are subject to varying degrees of risk. The yields available from investments in real estate depend on the amount of income and capital appreciation generated by the related properties. Income and real estate values may also be adversely affected by such factors as applicable domestic and foreign laws (e.g., Americans with Disabilities Act and tax laws), interest rate levels and the availability of financing. If the properties do not generate sufficient income to meet operating expenses, including, where applicable, debt service, ground lease payments, tenant improvements, third-party leasing commissions and other capital expenditures, the income and ability of the real estate company to make payments of any interest and principal on its debt securities will be adversely affected. In addition, real property may be subject to the quality of credit extended and

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defaults by borrowers and tenants. The performance of the economy in each of the countries and regions in which the real estate securities owned by a Fund is located affects occupancy, market rental rates and expenses and, consequently, has an impact on the income from such properties and their underlying values. The financial results of major local employers also may have an impact on the cash flow and value of certain properties. In addition, real estate investments are relatively illiquid and, therefore, the ability of real estate companies to vary their portfolios promptly in response to changes in economic or other conditions is limited. A real estate company such as a REIT may also have joint venture investments in certain of its properties and, consequently, its ability to control decisions relating to such properties may be limited.

REIT Risk. REITs are generally classified as equity REITs, mortgage REITs or a combination of equity and mortgage REITs. Equity REITs invest the majority of their assets directly in real property. Mortgage REITs invest the majority of their assets in real estate mortgages and derive income from the collection of interest payments. Hybrid REITs combine the characteristic of both equity and mortgage REITs. The FlexShares® Global Quality Real Estate Index Fund does not intend to invest in mortgage REITs. Equity REITs may be affected by changes in the value of the underlying property owned by the REITs. REITs are dependent upon management skill, may not be diversified, and are subject to heavy cash flow dependency, default by mortgagors or lessees and self-liquidation. In the event of a default by a mortgagor or lessee, a REIT may experience delays in enforcing its rights as a mortgagee or lessor and may incur substantial costs associated with protecting its investments. REITs are also subject to risks generally associated with investments in real estate. These risks include: changes in the value of real estate properties and difficulties in valuing and trading real estate; risks related to general and local economic conditions; overbuilding and increased competition; increases in property taxes and operating expenses; changes in zoning laws; casualty and condemnation losses; variations in rental income; changes in the appeal of property to tenants; tenant bankruptcies and other credit problems; and changes in interest rates. To the extent that assets underlying a REIT are concentrated geographically, by property type or in certain other

respects, these risks may be heightened. REITs are also subject to interest rate risks. A Fund will indirectly bear its proportionate share of any expenses, including management fees, paid by a REIT in which it invests.

REITs are subject to a highly technical and complex set of provisions in the Internal Revenue Code of 1986, as amended (the “Code”). It is possible that a Fund may invest in a real estate company that purports to be a REIT and that the company could fail to qualify as a REIT. In the event of any such unexpected failure to qualify as a REIT, the company would be subject to corporate-level taxation, significantly reducing the return to the Fund on its investment in such company.

The REIT investments of a Fund often do not provide complete tax information to the Fund until after the calendar year-end. Consequently, because of the delay, it may be necessary for a Fund to request permission to extend the deadline for issuance of Forms 1099-DIV beyond January 31. Also, under current provisions of the Code, distributions attributable to operating income of REITs in which a Fund invests are not eligible for favorable tax treatment as long-term capital gains or qualified dividends and will be taxable to you as ordinary income.

Sampling Risk. The use of a representative sampling approach may result in increased tracking error because the securities selected for a Fund in the aggregate may vary from the investment profile of its Underlying Index. Additionally, the use of a representative sampling approach may result in a Fund holding a smaller number of securities than its Underlying Index, and, as a result, an adverse development to an issuer of securities that the Fund holds could result in a greater decline in NAV than would be the case if the Fund held all of the securities in its Underlying Index.

Securities Lending Risk. In order to generate additional income, the Funds may lend securities to banks, brokers and dealers or other qualified institutions. In exchange, each Fund will receive collateral equal to at least 100% of the value of the securities loaned.

Securities lending may represent no more than one-third of the value of each Fund’s total assets (including the loan collateral). Any cash collateral received by each Fund in connection with these loans may be invested in a variety of

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Additional Fund Information (cont.)

short-term investments, either directly or indirectly through money market portfolios. Loan collateral (including any investment of the collateral) is not included in the calculation of the percentage limitations described elsewhere in this Prospectus regarding each Fund’s investments in particular types of securities.

A principal risk when lending portfolio securities is that the borrower might become insolvent or refuse to honor its obligation to return the securities. In this event, a Fund could experience delays in recovering its securities and possibly may incur a capital loss. A Fund will be responsible for any loss that might result from its investment of the cash collateral it receives from a borrower. Additionally, the amount of a Fund’s distributions that qualify for taxation at reduced long-term capital gains rates for individuals, as well as the amount of a Fund’s distributions that qualify for the dividends received deduction available to corporate shareholders (together, “qualifying dividends”) may be reduced as a result of a Fund’s securities lending activities. This is because any dividends paid on securities while on loan will not be deemed to have been received by the Fund, and the equivalent amount paid to the Fund by the borrower of the securities will not be deemed to be a qualifying dividend.

Seed Investor Risk. NTI and/or its affiliates may make payments to one or more investors that contribute seed capital to a Fund, such as an Authorized Participant, a market maker and/or another entity. Such payments may continue for a specified period of time and/or until a specified dollar amount is reached. Those payments will be made from the assets of NTI and/or its affiliates (and not the Fund). Seed investors may contribute all or a majority of the assets in the Fund. There is a risk that such seed investors may redeem all or part of their investments in the Fund, particularly after payments from NTI and/or its affiliates have ceased. As with redemptions by other large shareholders, redemptions by seed investors could affect the liquidity of the Fund’s portfolio, increase the Fund’s transaction costs, accelerate the realization of taxable income and/or gains, and result in the Fund’s expenses being allocated over a smaller asset base. A large redemption may also have a material upward or downward effect on the market price of the Fund’s shares and result in wider bid-ask spreads.

Substantial Volatility Risk. The value of the securities in a Fund’s portfolio may fluctuate, sometimes rapidly and unpredictably at a greater level than the overall market. The value of a security may fluctuate due to factors affecting markets generally or particular industries. This volatility may affect a Fund’s NAV. An Underlying Index is created to seek higher yields than the Parent Index and has exposure to securities likely to be more volatile than other similar securities. There is risk that a Fund could have substantial volatility.

Tax Risk. A Fund’s realized losses on sales of shares of an Underlying Fund may be indefinitely or permanently deferred as “wash sales.” Distributions of short term capital gains by the Underlying Funds will be recognized as ordinary income by the Fund and would not be offset by the Fund’s capital loss carryforwards, if any. Capital loss carryforwards of the Underlying Funds, if any, would not offset net capital gains of the Fund. Each of these effects is caused by the Fund’s investment in the Underlying Funds and may result in distributions to Fund shareholders being of higher magnitudes and less likely to qualify for lower capital gain tax rates than if the Fund were to invest otherwise.

Tracking Error Risk. Tracking error risk is the risk that a Fund’s performance may vary substantially from the performance of the Underlying Index it tracks as a result of imperfect correlation between a Fund’s securities and those of the Underlying Index. Imperfect correlation may result from share purchases and redemptions, expenses, cash holdings, changes in the Underlying Indexes, asset valuations, costs of entering into foreign currency forward contracts, foreign currency valuations, market impact, corporate actions (such as mergers and spin-offs), legal restrictions (such as tax-related diversification requirements that apply to the Funds but not to the Underlying Index) and timing variances, among other factors. This risk may be heightened during times of increased market volatility or other unusual market conditions.

Tracking error risk may be higher for Funds that track a foreign index, or an index that includes foreign securities, because regulatory and reporting requirements may differ

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Additional Fund Information (cont.)

from those in the U.S., and there is a heightened risk associated with limited availability and reliability of data used to construct the index.

For purposes of calculating the Funds' NAVs, the value of assets denominated in non-U.S. currencies is converted into U.S. dollars using prevailing market rates on the date of valuation as quoted by one more data service providers. This conversion may result in a difference between the prices used to calculate the Fund's NAV and the prices used by the Underlying Index, which, in turn, could result in a difference between a Fund's performance and the performance of its Underling Index.

The need to comply with tax diversification and other requirements of the Internal Revenue Code of 1986, as amended, may also impact a Fund's ability to replicate the performance of its Underlying Index.

U.S. Government Securities Risk. Not all U.S. government obligations carry the same credit support. Although many U.S. government securities in which a Fund may invest, such as those issued by Fannie Mae and Freddie Mac, may be chartered or sponsored by Acts of Congress, their securities are neither issued nor guaranteed by the U.S. Treasury and, therefore, are not backed by the full faith and credit of the United States. Some, such as those of Ginnie Mae, are supported by the full faith and credit of the U.S. Treasury. Other obligations, such as those of the Federal Home Loan Banks, are supported by the right of the issuer to borrow from the U.S. Treasury; and others are supported by the discretionary authority of the U.S. government to purchase the agency’s obligations. Still others are supported only by the credit of the instrumentality or sponsored enterprise. The maximum potential liability of the issuers of some U.S. government securities held by a Fund may greatly exceed their current resources, including their legal right to support from the U.S. Treasury. It is possible that these issuers will not have the funds to meet their payment obligations in the future. No assurance can be given that the U.S. government would provide financial support to its agencies, instrumentalities or sponsored enterprises if it is not obligated to do so by law.

An agency of the U.S. government has placed Fannie Mae and Freddie Mac into conservatorship, a statutory process

with the objective of returning the entities to normal business operations. It is unclear what effect this conservatorship will have on the securities issued or guaranteed by Fannie Mae or Freddie Mac. As a result, these securities are subject to more credit risk than U.S. government securities that are supported by the full faith and credit of the United States (e.g., U.S. Treasury bonds).

To the extent a Fund invests in debt instruments or securities of non-U.S. government entities that are backed by the full faith and credit of the United States, there is a possibility that such guarantee may be discontinued or modified at a later date.

Valuation Risk. The sale price the Funds could receive for a security may differ from the Funds’ valuation of the security, particularly for securities that trade in low volume or volatile markets, or that are valued using a fair value methodology. Fair valuation of the Funds’ investments involves subjective judgment. Because portfolio securities of certain Funds may be traded on non-U.S. exchanges, and non-U.S. exchanges may be open on days when a Fund does not price its shares, the value of the securities in a Fund’s portfolio may change on days when shareholders will not be able to purchase or sell the Fund’s shares. The Funds rely on various sources to calculate their respective NAVs. The information may be provided by third parties that are believed to be reliable, but the information may not be accurate due to errors by such pricing sources, technological issues or otherwise.

Value Investing Risk. A Fund’s investment in companies whose securities are believed to be undervalued, relative to their underlying profitability, may not appreciate in value as anticipated.

Value Score Risk. A Fund’s investment in companies whose securities are believed to be undervalued may not appreciate in value as anticipated. Although the Fund’s Underlying Index is designed to measure a portfolio of bonds of companies with the potential for higher yields and less risk of insolvency relative to the Fund’s Parent Index, there is no assurance that the Underlying Index or the Fund will be comprised of such securities. Accordingly, the Fund may be subject to greater credit risk, price volatility and risk of loss relative to its Parent Index.

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Additional Fund Information (cont.)

Volatility Risk. The actual level of volatility experienced by a Fund may be greater or lower than the targeted overall volatility of the Fund’s Underlying Index. Although a Fund’s Underlying Index is designed to have a targeted overall volatility that is similar to that of the Parent Index, there is no guarantee that it will have the targeted overall volatility. A Fund will continue to seek to track the Underlying Index even if the Underlying Index does not have the targeted overall volatility. There is also the risk that a Fund may experience volatility greater or lower than that of the Underlying Index as a result of tracking error. A portfolio of securities with greater volatility is generally considered to have a higher risk profile than a portfolio with lower volatility.

Additional Information About the Funds’ Investments and Other Risks

The principal risks of investing in the Funds are described under each “Fund Summary” above, and in “Additional Information About the Funds’ Principal Risks” above on page 195. This section provides additional information about some of the investments and related risks described under the “Fund Summary” for each Fund above. It also describes additional risks faced by the Funds and investment techniques that may be used by the Funds from time to time. This Prospectus does not attempt to disclose all of the various types of instruments and investment techniques that may be used by the Funds. As with any fund, investors in the Funds rely on the professional investment judgment and skill of the Investment Adviser and the individual portfolio managers. Please see the SAI for more information about the securities and investment techniques described in this section and about other strategies and techniques that may be used by the Funds.

The FlexShares® Real Assets Allocation Index Fund may be exposed to these risks directly, or indirectly through the Fund’s investments in the Underlying Funds.

Borrowings and Reverse Repurchase Agreements. To the extent consistent with its investment policies, each Fund may borrow money and enter into reverse repurchase agreements in amounts not exceeding one-third of the value of its total assets (including the amount borrowed). Each Fund may enter into reverse repurchase agreements when the Investment Adviser expects that the interest

income to be earned from the investment of the transaction proceeds will be greater than the related interest expense. Reverse repurchase agreements involve the sale of securities held by a Fund subject to the Fund’s agreement to repurchase them at a mutually agreed upon date and price (including interest).

Borrowings and reverse repurchase agreements involve leveraging. If the securities held by a Fund decline in value while these transactions are outstanding, the NAV of the Fund’s outstanding shares will decline in value by proportionately more than the decline in value of the securities. In addition, reverse repurchase agreements involve the risks that (a) the interest income earned by a Fund (from the investment of the proceeds) will be less than the interest expense of the transaction; (b) the market value of the securities sold by the Fund will decline below the price the Fund is obligated to pay to repurchase the securities; and (c) the securities may not be returned to the Fund.

Cyber Security and Operational Risk. The Funds and their service providers may experience disruptions that arise from breaches in cyber security, human error, processing and communications errors, counterparty or third-party errors, technology or systems failures, any of which may have an adverse impact on the Funds. Failures or breaches of the electronic systems of the Funds, the Investment Adviser, distributor, and other service providers, market makers, Authorized Participants (collectively, the “Service Providers”) or the issuers of securities in which the Funds invest have the ability to cause disruptions and negatively impact the Funds’ business operations, potentially resulting in financial losses to the Funds and their shareholders.

With the increased use of the Internet and because information technology (“IT”) systems and digital data underlie most of the Funds’ operations, the Funds and their Service Providers and their vendors are exposed to the risk that their operations and data may be compromised as a result of internal and external cyber-failures, breaches or attacks (“Cyber Risk”). This could occur as a result of malicious or criminal cyber-attacks. Cyber-attacks include actions taken to: (i) steal or corrupt data maintained online or digitally, (ii) gain unauthorized access to or release confidential information, (iii) shut down a Fund or Service Provider website through denial-of-service attacks or (iv) otherwise

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disrupt normal business operations. However, events arising from human error, faulty or inadequately implemented policies and procedures or other systems failures unrelated to any external cyber-threat may have effects similar to those caused by deliberate cyber-attacks. Among other situations, disruptions (for example, pandemics and health crises) that cause prolonged periods of remote work or significant employee absences at the Funds' service providers could impact the ability to conduct the Funds’ operations.

Successful cyber-attacks or other cyber-failures or events affecting the Funds or their Service Providers may adversely impact a Fund or its shareholders or cause an investment in the Fund to lose value. For instance, they may impact a Fund’s ability to calculate its NAV, cause the release of confidential Fund information, impede trading, or cause reputational damage. They could also subject a Fund or its Service Providers to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and/or additional compliance costs. Insurance protection and contractual indemnification provisions may not be available or may be insufficient to cover these losses. The Funds or their Service Providers may also incur significant costs to manage and control Cyber Risk.

Cyber Risks are also present for issuers of securities or other instruments in which the Funds invest, which could result in material adverse consequences for such issuers, and may cause a Fund’s investment in such issuers to lose value.

While the Investment Adviser, Service Providers or Authorized Participants may have established business continuity plans and risk management systems to prevent such cyber attacks, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified or that cyber attacks may be highly sophisticated.

The Funds and their shareholders could be negatively impacted as a result.

Fixed-Income Market Conditions. Conditions in the U.S. and many foreign economies have resulted, and may continue to result, in fixed income instruments experiencing unusual liquidity issues, increased price volatility and, in some cases, credit downgrades and increased likelihood of

default. These events have reduced the willingness and ability of some lenders to extend credit, and have made it more difficult for borrowers to obtain financing on attractive terms, if at all. As a result, the values of many types of securities have been reduced. In addition, global economies and financial markets are becoming increasingly interconnected, which increases the possibilities that conditions in one country or region might adversely impact issuers in a different country or region. The severity or duration of adverse economic conditions may also be affected by policy changes made by governments or quasi-governmental organizations. In addition, political events within the U.S. and abroad, such as the U.S. government’s recent inability to agree on a long-term budget and deficit reduction plan, the federal government shutdown and threats to not increase the federal government’s debt limit, may affect investor and consumer confidence and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree. High public debt in the U.S. and other countries creates ongoing systemic and market risks and policymaking uncertainty.

Investment Companies. The Funds may invest in securities of other investment companies, including other ETFs. Such investments may include money market funds and other exchange-traded funds managed by the Investment Adviser.

Investment Grade Securities. A security is considered investment grade if, at the time of acquisition, it is rated:

•BBB of higher by S&P Global Ratings (“S&P”);

•Baa3 or higher by Moody’s Investors Service, Inc. (“Moody’s”);

•BBB or higher by Fitch Ratings (“Fitch”); or

•BBB or higher by DBRS Ratings Limited (“DBRS”).

A security will be considered investment grade if it receives one of the above ratings, or a comparable rating from another organization that is recognized as a NRSRO, even if it receives a lower rating from other rating organizations. An unrated security also may be considered investment grade if the Investment Adviser determines that the security is comparable in quality to a security that has been rated investment grade.

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Additional Fund Information (cont.)

Generally, the lower the credit rating of a security, issuer, guarantor or counterparty, the higher the degree of risk as to payment of interest and return of capital. Although securities rated BBB by S&P, DBRS or Fitch, or Baa3 by Moody’s are considered investment grade, they have certain speculative characteristics. Therefore, they may be subject to a higher risk of default than obligations with higher ratings. Subsequent to its purchase by a Fund, a rated security may cease to be rated or its rating may be reduced below investment grade or a security may no longer be considered to be investment grade. In such case, the Fund is not required to dispose of the security.

Large Shareholder Risk. Certain shareholders, including other funds advised by the Investment Adviser, may from time to time own a substantial amount of a Fund’s shares. In addition, a third-party investor, the Investment Adviser or an affiliate of the Investment Adviser, an authorized participant, a market maker, or another entity may invest in a Fund and hold its investment for a limited period of time solely to facilitate commencement of the Fund or to facilitate the Fund’s achieving a specified size or scale. There can be no assurance that any large shareholder would not redeem its investment, that the size of a Fund would be maintained at such levels or that a Fund would continue to meet applicable listing requirements. Redemptions by large shareholders could have a significant negative impact on a Fund. In addition, transactions by large shareholders may account for a large percentage of the trading volume on a Fund’s listing exchange and may, therefore, have a material upward or downward effect on the market price of the shares.

To the extent a significant percentage of the shares of a Fund are owned or controlled by a small number of account shareholders (or a single account shareholder), including funds or accounts over which the Investment Adviser or an affiliate of the Investment Adviser has investment discretion, the Fund is subject to the risk that those shareholders may purchase or redeem Fund shares in significant amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Investment Adviser or an affiliate of the Investment Adviser and may adversely affect a Fund’s performance if the Investment Adviser is forced to sell portfolio securities or invest cash when the Investment Adviser would not otherwise

choose to do so. Redemptions of a large number of shares may affect the liquidity of a Fund’s portfolio, increase the Fund’s transaction costs, and accelerate the realization of taxable income and/or gains. In addition, a large redemption could result in each Fund’s current expenses being allocated over a smaller asset base, leading to an increase in such Fund’s gross expense ratio. Large purchases of a Fund’s shares may also adversely affect the Fund’s performance to the extent that a Fund is delayed in investing new cash or otherwise maintains a larger cash position than it ordinarily would to the extent that the Fund accepts cash for an order for the purchase of creation units of the Fund’s shares.

Mortgage Dollar Rolls. A Fund may invest in mortgage dollar rolls to the extent consistent with its investment objective and strategies. A mortgage dollar roll involves the sale by the Fund of securities for delivery in the future (generally within 30 days). The Fund simultaneously contracts with the same counterparty to repurchase substantially similar (same type, coupon and maturity) but not identical securities on a specified future date. During the roll period, the Fund loses the right to receive principal and interest paid on the securities sold. However, the Fund benefits to the extent of any difference between (a) the price received for the securities sold and (b) the lower forward price for the future purchase and/or fee income plus the interest earned on the cash proceeds of the securities sold. Successful use of mortgage dollar rolls depends upon the Investment Adviser’s ability to predict correctly interest rates and mortgage prepayments. If the Investment Adviser is incorrect in its prediction, the Fund may experience a loss. Unless the benefits of a mortgage dollar roll exceed the income, capital appreciation and gain or loss due to mortgage prepayments that would have been realized on the securities sold as part of the roll, the use of this technique will diminish the Fund’s performance.

For financial reporting and tax purposes, the Funds treat mortgage dollar rolls as two separate transactions: one involving the purchase of a security and a separate transaction involving a sale. The Funds currently do not intend to enter into mortgage dollar rolls that are accounted for as financing and does not treat them as borrowings.

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Additional Fund Information (cont.)

Repurchase Agreements. To the extent consistent with its investment policies, each Fund may enter into repurchase agreements with financial institutions such as banks and broker-dealers that are deemed to be creditworthy by the Investment Adviser. Repurchase agreements involve the purchase of securities by a Fund subject to the seller’s agreement to repurchase them at a mutually agreed upon date and price. In the event of a default, the Funds will suffer a loss to the extent that the proceeds from the sale of the underlying securities and other collateral are less than the repurchase price and the Funds’ costs associated with delay and enforcement of the repurchase agreement. In addition, in the event of bankruptcy, the Funds could suffer additional losses if a court determines that the Funds’ interest in the collateral is unenforceable by the Funds.

Each Fund intends to enter into transactions with counterparties that are creditworthy at the time of the transactions. There is always the risk that the Investment Adviser’s analysis of creditworthiness is incorrect or may change due to market conditions. To the extent that a Fund focuses its transactions with a limited number of counterparties, it will be more susceptible to the risks associated with one or more counterparties. With respect to collateral received in repurchase transactions or other investments, the Funds may have significant exposure to the financial services and mortgage markets. Such exposure, depending on market conditions, could have a negative impact on the Funds, including minimizing the value of any collateral.

Rule 144A Securities. The Underlying Index of certain Funds may include securities offered pursuant to Rule 144A of the Securities Act, and each Fund may purchase these types of securities to the extent consistent with its investment objective and strategies. Rule 144A securities may be resold only to qualified institutional buyers and other conditions are met for resale. Because there may be relatively few potential purchasers for such securities, especially under adverse market or economic conditions or in the event of adverse changes in the financial condition of the issuer, each Fund may find it more difficult to sell such securities or it may be able to sell such securities only at prices lower than if such securities were more widely held

or traded. At times, it also may be more difficult to determine the fair value of such securities for purposes of computing the Fund’s NAV due to the absence of an active trading market. There can be no assurance that a security that is deemed to be liquid when purchased will continue to be liquid for as long as it is held by each Fund.

In recognition of the increased size and liquidity of the institutional market for unregistered securities and the importance of institutional investors in the formation of capital, the SEC adopted Rule 144A under the Securities Act. Rule 144A is designed to facilitate efficient trading among institutional investors by permitting the sale of certain unregistered securities to qualified institutional buyers. To the extent privately placed securities held by a Fund qualify under Rule 144A and an institutional market develops for those securities, the Funds likely will be able to dispose of the securities without registering them under the Securities Act. To the extent that institutional buyers become, for a time, uninterested in purchasing these securities, investing in Rule 144A securities could increase the level of a Fund’s illiquidity.

Structured Securities. A Fund may invest in structured securities to the extent consistent with its investment objective and strategies. Structured securities present additional risk that the interest paid to a Fund on a structured security will be less than expected. The value of such securities is determined by reference to changes in the value of specific currencies, interest rates, commodities, securities, indices or other financial indicators (the “Reference”) or the relative change in two or more References. The interest rate or the principal amount payable upon maturity or redemption may be increased or decreased depending upon changes in the applicable Reference. Examples of structured securities include, but are not limited to, asset-backed commercial paper, structured notes and other debt obligations, where the principal repayment at maturity is determined by the value of a specified security or securities index.

The terms of some structured securities may provide that in certain circumstances no principal is due at maturity and, therefore, the Fund could suffer a total loss of its investment. Structured securities may be positively or negatively indexed, so that appreciation of the Reference

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Additional Fund Information (cont.)

may produce an increase or decrease in the interest rate or value of the security at maturity. In addition, changes in the interest rates or the value of the security at maturity may be a multiple of changes in the value of the Reference. Consequently, structured securities may entail a greater degree of market risk than other types of securities. Structured securities also may be more volatile, less liquid and more difficult to accurately price than less complex securities due to their derivative nature. As a result, investments in structured securities may adversely affect the Fund’s NAV. In some cases it is possible that the Fund may suffer a total loss on its investment in a structured security.

Variable and Floating Rate Instruments. A Fund may invest in variable and floating rate instruments to the extent consistent with its investment objective and strategies. Variable and floating rate instruments have interest rates that periodically are adjusted either at set intervals or that float at a margin tied to a specified index rate. These instruments include floating rate Treasury obligations, variable amount master demand notes, long-term variable and floating rate bonds where a Fund obtains at the time of purchase the right to put the bond back to the issuer or a third party at par at a specified date and leveraged inverse floating rate instruments (“inverse floaters”). An inverse floater is leveraged to the extent that its interest rate varies by an amount that exceeds the amount of the variation in the index rate of interest. Some variable and floating rate instruments have interest rates that periodically are adjusted as a result of changes in inflation rates.

The market values of inverse floaters are subject to greater volatility than other variable and floating rate instruments due to their higher degree of leverage. Because there is no active secondary market for certain variable and floating rate instruments, they may be more difficult to sell if the issuer defaults on its payment obligations or during periods when a Fund is not entitled to exercise its demand rights. As a result, a Fund could suffer a loss with respect to these instruments. In addition, variable and floating rate instruments are subject to changes in value based on changes in market interest rates or changes in the issuer’s or guarantor’s creditworthiness.

When-Issued Securities, Delayed Delivery Transactions and Forward Commitments. A Fund may enter into

when-issued, delayed delivery and forward commitment transactions to the extent consistent with its investment objective and strategies. A purchase of “when-issued” securities refers to a transaction made conditionally because the securities, although authorized, have not yet been issued. A delayed delivery or forward commitment transaction involves a contract to purchase or sell securities for a fixed price at a future date beyond the customary settlement period.

Although a Fund generally would purchase securities in these transactions with the intention of acquiring the securities, the Fund may dispose of such securities prior to settlement if the Investment Adviser deems it appropriate to do so.

Purchasing securities on a when-issued, delayed delivery or forward commitment basis involves the risk that the value of the securities may decrease by the time they actually are issued or delivered. Conversely, selling securities in these transactions involves the risk that the value of the securities may increase by the time they actually are issued or delivered.

These transactions also involve the risk that the counterparty may fail to deliver the security or cash on the settlement date. If this occurs, a Fund may lose both the investment opportunity for the assets it set aside to pay for the security and any gain in the security’s price.

Zero Coupon, Pay-In-Kind and Capital Appreciation Bonds. Each Fund may invest in zero coupon, pay-in-kind and capital appreciation bonds to the extent consistent with its investment objective and strategies. These are securities issued at a discount from their face value because interest payments typically are postponed until maturity. Interest payments on pay-in-kind securities are payable by the delivery of additional securities. The amount of the discount rate varies depending on factors such as the time remaining until maturity, prevailing interest rates, a security’s liquidity and the issuer’s credit quality. These securities also may take the form of debt securities that have been stripped of their interest payments.

The market prices of zero coupon, pay-in-kind and capital appreciation bonds generally are more volatile than the market prices of interest-bearing securities and are likely to respond to a greater degree to changes in interest rates than

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Additional Fund Information (cont.)

interest-bearing securities having similar maturities and credit quality. Each Fund’s investments in zero coupon, pay-in-kind and capital appreciation bonds may require the investing Fund to sell some of its portfolio securities to generate sufficient cash to satisfy certain income distribution requirements.

Portfolio Holdings Information

A description of the Trust’s policies and procedures with respect to the disclosure of the Funds’ portfolio securities is available in the Funds’ SAI. The top holdings of each Fund can be found at flexshares.com. Fund fact sheets provide information regarding the Funds’ top holdings and may be requested by calling 1-855-FLEXETF (1-855-353-9383) or visiting the Trust’s website flexshares.com.

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Description of Fund Management

Investment Adviser

Northern Trust Investments, Inc. (“NTI” or the “Investment Adviser”), a subsidiary of Northern Trust Corporation, serves as the Investment Adviser of each of the Funds. NTI is located at 50 South LaSalle Street, Chicago, IL 60603.

NTI is an Illinois State Banking Corporation and an investment adviser registered under the Investment Advisers Act of 1940, as amended. It primarily manages assets for institutional and individual separately managed accounts, investment companies and bank common and collective funds. Northern Trust Corporation is regulated by the Board of Governors of the Federal Reserve System as a financial holding company under the U.S. Bank Holding Company Act of 1956, as amended.

As of December 31, 2023, Northern Trust Corporation, through its affiliates, had assets under investment management of $1.4 trillion and assets under custody of $11.9 trillion.

Under the Investment Advisory Agreement with the Funds, NTI, subject to the general supervision of the Board of Trustees, is responsible for making investment decisions for the Funds and for placing purchase and sale orders for portfolio securities.

As compensation for its advisory services and assumption of Fund expenses, NTI is entitled to a unitary management fee (“Management Fee”), computed daily and payable monthly as reflected in the table below. From the unitary management fee, NTI pays most of the expenses of the Fund, including the cost of transfer agency, custody, fund administration, legal, audit and other services. However, it is not responsible for fee payments under the Investment Advisory Agreement, interest expenses, distribution fees and expenses paid by the Funds under any distribution plan adopted pursuant to Rule 12b-1 under the 1940 Act (“12b-1 Fees”), brokerage commissions and other trading expenses, fees and expenses of the independent trustees and their independent legal counsel, taxes and other extraordinary costs such as (i) dividend expenses on short sales; (ii) non-routine items, including litigation expenses and proxy expenses; and (iii) expenses that the Fund has incurred but did not actually pay due to an expense offset arrangement, if applicable.

The following table reflects the unitary management fees paid in the last fiscal year by each Fund that has completed a full fiscal year (expressed as a percentage of the Fund’s average daily net assets).

Fund	Unitary Management Fee (as a percentage of the Fund’s average daily net assets) paid to NTI as of 10/31/23
FlexShares® US Quality Low Volatility Index Fund	0.22%(1)
FlexShares® Developed Markets ex-US Quality Low Volatility Index Fund	0.32%
FlexShares® Emerging Markets Quality Low Volatility Index Fund	0.40%
FlexShares® Morningstar US Market Factor Tilt Index Fund	0.25%
FlexShares® Morningstar Developed Markets ex-US Factor Tilt Index Fund	0.39%
FlexShares® Morningstar Emerging Markets Factor Tilt Index Fund	0.59%(2)
FlexShares® US Quality Large Cap Index Fund	0.25%
FlexShares® STOXX® US ESG Select Index Fund	0.32%
FlexShares® STOXX® Global ESG Select Index Fund	0.42%
FlexShares® ESG & Climate US Large Cap Core Index Fund	0.09%
FlexShares® ESG & Climate Developed Markets ex-US Core Index Fund	0.12%

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Description of Fund Management (cont.)

Fund	Unitary Management Fee (as a percentage of the Fund’s average daily net assets) paid to NTI as of 10/31/23
FlexShares® ESG & Climate Emerging Markets Core Index Fund	0.18%
FlexShares® Morningstar Global Upstream Natural Resources Index Fund	0.46%
FlexShares® STOXX® Global Broad Infrastructure Index Fund	0.47%
FlexShares® Global Quality Real Estate Index Fund	0.45%
FlexShares® Real Assets Allocation Index Fund	0.49%
FlexShares® Quality Dividend Index Fund	0.37%
FlexShares® Quality Dividend Defensive Index Fund	0.37%
FlexShares® International Quality Dividend Index Fund	0.47%
FlexShares® International Quality Dividend Defensive Index Fund	0.47%
FlexShares® International Quality Dividend Dynamic Index Fund	0.47%
FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund	0.18%
FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund	0.18%
FlexShares® Disciplined Duration MBS Index Fund	0.20%

Fund	Unitary Management Fee (as a percentage of the Fund’s average daily net assets) paid to NTI as of 10/31/23
FlexShares® Credit-Scored US Corporate Bond Index Fund	0.22%(3)
FlexShares® Credit-Scored US Long Corporate Bond Index Fund	0.22%(4)
FlexShares® High Yield Value-Scored Bond Index Fund	0.37%
FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund	0.12%

(1) Effective January 1, 2024 the Unitary Management Fee was reduced to 0.17%.

(2) Effective January 1, 2024 the Unitary Management Fee was reduced to 0.57%.

(3) Effective January 1, 2024 the Unitary Management Fee was reduced to 0.15%.

(4) Effective January 1, 2024 the Unitary Management Fee was reduced to 0.15%.

NTI has contractually agreed to reimburse a portion of the operating expenses of each Fund (other than 12b-1 Fees, tax expenses, extraordinary expenses, and acquired fund fees and expenses as calculated pursuant to Form N-1A (“Acquired Fund Fees and Expenses”)) so that “Total Annual Fund Operating Expenses After Expense Reimbursement” do not exceed the Fund’s Management Fee plus (+) .0049%. NTI also has contractually agreed until March 1, 2025 in the case of the FlexShares® Real Assets Allocation Index Fund to waive Management Fees or reimburse certain expenses in an amount equal to the Acquired Fund Fees and Expenses attributable to the Fund’s investments in other Funds.

The contractual expense reimbursement arrangements are expected to continue until at least March 1, 2025 and will continue automatically thereafter for periods of one year (each such one-year period, a “Renewal Year”). The contractual arrangements may be terminated with respect to a Fund, as to any succeeding Renewal Year, by NTI or the Fund upon 60 days’ written notice prior to the end of the

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Description of Fund Management (cont.)

current Renewal Year. The Board of Trustees may terminate the arrangements at any time with respect to a Fund if it determines that it is in the best interest of the Fund and its shareholders.

NTI may reimburse additional expenses or waive all or a portion of the management fees of the Funds. Any such additional expense reimbursement or fee waiver would be voluntary and could be implemented, increased or decreased, or discontinued at any time. A discussion regarding the Board of Trustees’ basis for its approval of the Advisory Agreement for each Fund is available in the Trust’s annual report to shareholders for the period ended October 31, 2023.

Portfolio Managers

NTI manages assets collectively on a team basis, which allows the firm to maintain continuity of the investment management process. NTI’s Chief Investment Officer leads various teams with respect to strategic overall investment management decisions and the development of investment strategies. Senior investment professionals from NTI’s portfolio management teams are involved in various aspects of managing the Funds. Portfolio managers within each specialized team are responsible for the day-to-day management of specific investment strategies and funds.

David M. Alongi is a Senior Vice President of NTI. Mr. Alongi joined NTI in 2000 and is responsible for leading the portfolio management and trading process for passive fixed-income portfolios.

Robert Anstine is a Senior Vice President of NTI. Mr. Anstine joined NTI in 2011 and is responsible for managing various global index equity portfolios. In addition, he has been involved with the investment management of the FlexShares® equity index funds since their inception. Prior to joining NTI and since 2007, Mr. Anstine worked at Northern Trust as an operations manager.

Alan Aung is a Vice President of NTI. Mr. Aung joined NTI in 2017 and is responsible for managing index equity portfolios. Prior to joining NTI, Mr. Aung was a Portfolio Manager at iShares on the US iShares team.

Volter Bagriy is a Vice President of NTI. Mr. Bagriy joined NTI in September 2012 and is a Senior Portfolio Manager within the Global Index Team. Mr. Bagriy focuses on management of portfolios within international equities, and has a specialization in managing sustainable investing strategies. In addition, he is a member of NTI's global sustainable investing resource team.

Michael R. Chico is a Vice President of NTI. Mr. Chico joined NTI in 2007 and is responsible for managing various fixed-income funds.

Mousumi Chinara, CFA, is a Vice President of NTI. Ms. Chinara joined NTI in 2019 and is responsible for managing index fixed income portfolios including mutual funds, ETFs as well as various separately managed accounts. Prior to joining NTI, Ms. Chinara worked at Reinsurance Group of America (RGA) and VOYA Investment Management as a Portfolio Manager responsible for various U.S., Canada and Asia Pac based clients. Ms. Chinara earned an MBA in finance from Emory University. She is a CFA® charter holder, a member of the CFA Institute and CFA Society of Chicago.

Benjamin Gord is a Senior Vice President and Head of Fixed Income Portfolio Implementation of NTI. Mr. Gord joined NTI in 2022 and oversees the Fixed Income Portfolio Construction and Quantitative Research Teams. He also sits on the Fixed Income Strategy Team which sets risk allocation for all fixed income portfolios. Prior to joining NTI, Mr. Gord was a Managing Director at Ellington Management Group and before that at Wafra.

Chaitanya Mandavakuriti, CFA, is a Vice President of NTI. Mr. Mandavakuriti joined NTI in 2013 and has assisted in the management of international fixed income index portfolios with a focus on credit.

Kevin O’Shaughnessy is a Vice President of NTI. Mr. O’Shaughnessy joined NTI in 1997 and is responsible for managing various fixed-income funds.

Steven Santiccoli is a Vice President of NTI. Mr. Santiccoli joined NTI in 1993 and is responsible for managing various global index equity portfolios. In

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Description of Fund Management (cont.)

addition, he is a member of NTI’s global sustainable investing resource team.

Brendan Sullivan is a Vice President of NTI. Mr. Sullivan joined NTI in 2012 and is a Senior Portfolio Manager responsible for the management of international equity index portfolios, overlay mandates and equity exchange-traded funds.

Yair Walny is a Vice President of NTI. Mr. Walny joined NTI in 2009 and is a Senior Portfolio Manager responsible for the management of international equity index portfolios, overlay mandates and equity exchange-traded funds.

Eric R. Williams is a Senior Vice President of NTI. Mr. Williams joined NTI in January 2010 and has assisted in the management of various fixed-income funds.

Additional information about the Portfolio Managers’ compensation, other accounts managed by the Portfolio Managers and the Portfolio Managers’ ownership of securities in the Funds is available in the SAI.

Legal Proceedings

On or about February 14, 2020, Marc S. Kirschner, as Trustee for NWHI Litigation Trust (the “Litigation Trustee”), and Wilmington Savings Fund Society, FSB, as successor indenture trustee for various series of notes issued by Nine West Holdings, Inc. (individually, the “Indenture Trustee”, and together with the Litigation Trustee, “Plaintiffs”), filed separate complaints in the United States District Court for the Northern District of Illinois (case nos. 20-cv-01129 and 20-cv-01136, respectively) against a group of defendants that had purportedly invested in The Jones Group Inc. (“Jones Group”), including the FlexShares® Morningstar US Market Factor Tilt Index Fund. The claims in these actions stem from a series of merger transactions (“Transactions”) entered into by Jones Group (later renamed Nine West) and others in 2014 that allegedly rendered Jones Group insolvent. The FlexShares® Morningstar US Market Factor Tilt Index Fund allegedly received $224,910.00 as a result of the Transactions. The Plaintiffs seek to clawback these proceeds for the benefit of the Trust and the noteholders on the basis that they allegedly were fraudulent conveyances.

These proceedings, along with several substantially similar actions filed in other districts, were transferred from the United States District Court for the Northern District of Illinois to the United States District Court for the Southern District of New York to centralize the litigation, and were assigned to the Honorable Jed S. Rakoff for coordinated or consolidated pretrial proceedings.

On June 29, 2020, the former public shareholder defendants, including FlexShares® Morningstar US Market Factor Tilt Index Fund, filed a motion to dismiss on the basis that the payments made to them in connection with the Transactions were shielded from the fraudulent conveyance claims under Section 546(e) of the Bankruptcy Code. On August 27, 2020, all fraudulent conveyance claims against the former public shareholder defendants were dismissed. Plaintiffs appealed that decision before the U.S. Court of Appeals for the Second Circuit. On November 27, 2023, the Second Circuit affirmed the District Court’s decision insofar as it dismissed all fraudulent conveyance claims against the public shareholder defendants, agreeing with the District Court that the payments made to the public shareholders in connection with the leveraged buyout were safe harbored under Bankruptcy Code Section 546(e). The decision of the Second Circuit remains subject to potential further appeals. The Fund intends to continue to vigorously defend itself against this action.

Administrator, Custodian, Transfer Agent and Securities Lending Agent

JPMorgan Chase Bank, N.A. (“JPMorgan”) is the administrator, custodian, transfer agent and securities lending agent for each Fund.

Distributor

Foreside Fund Services, LLC, a Delaware limited liability company, serves as the distributor (“Distributor”) of Creation Units for the Funds on an agency basis. The Distributor does not maintain a secondary market in shares of any Fund. The Distributor has no role in determining the policies of the Funds or the securities that are purchased or sold by the Funds. The Distributor’s principal address is Three Canal Plaza, Portland, Maine 04101. The Distributor is not affiliated with NTI or with JPMorgan or its affiliates.

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Shareholder Information

Additional shareholder information is available free of charge by calling toll-free: 1-855-FLEXETF (1-855-353-9383) or visiting the Trust’s website at flexshares.com.

Buying and Selling Shares

Shares of the Funds trade on national securities exchanges during the trading day. Shares can be bought and sold throughout the trading day like other shares of publicly traded securities. There is no minimum investment. When buying or selling shares through a broker, you will incur customary brokerage commissions and charges. In addition, you will also incur the cost of the “spread,” which is the difference between what professional investors are willing to pay for Fund shares (the “bid” price) and the price at which they are willing to sell Fund shares (the “ask” price). The commission is frequently a fixed amount and may be a significant proportional cost for investors seeking to buy or sell small amounts of shares. The spread with respect to shares of a Fund varies over time based on the Fund’s trading volume and market liquidity, and is generally lower if the Fund has a lot of trading volume and market liquidity and higher if the Fund has little trading volume and market liquidity. Because of the costs of buying and selling Fund shares, frequent trading may reduce investment return and an investment in the Funds may not be advisable for investors who anticipate regularly making small investments.

Shares of the Funds may be acquired or redeemed directly from a Fund only in aggregate blocks of Shares or multiples thereof (“Creation Units”). Once created, shares of the Funds generally trade in the secondary market in amounts less than a Creation Unit.

Shares of the Funds trade under the trading symbols listed for each Fund on the front cover of this Prospectus.

The Board of Trustees has adopted a policy whereby the Funds do not monitor for frequent purchases and redemptions of Fund shares (“frequent trading”). The Board of Trustees believes that a frequent trading monitoring policy is unnecessary for the Funds because shares of the Funds are listed and traded on national securities exchanges. Therefore, it is unlikely that a shareholder could take advantage of a potential arbitrage opportunity presented by a lag between a change in the value of a Fund’s portfolio securities after the close of the primary markets for the

Fund’s portfolio securities and the reflection of that change in the Fund’s NAV, because each Fund sells and redeems its shares directly through transactions that are in-kind and/or for cash.

The national securities exchanges on which the Funds are listed are open for trading Monday through Friday and are closed on weekends and the following holidays, as observed: New Year’s Day, Martin Luther King, Jr. Day, Washington’s Birthday, Good Friday, Memorial Day, Juneteenth National Independence Day, Independence Day, Labor Day, Thanksgiving Day and Christmas Day.

Book Entry

Shares of the Funds are held in book-entry form, which means that no stock certificates are issued. The Depository Trust Company (“DTC”) or its nominee is the record owner of all outstanding shares of each Fund and is recognized as the owner of all shares for all purposes.

Investors owning shares of the Funds are beneficial owners as shown on the records of DTC or its participants. DTC serves as the securities depository for all shares of the Funds. DTC participants include securities brokers and dealers, banks, trust companies, clearing corporations and other institutions that directly or indirectly maintain a custodial relationship with DTC. As a beneficial owner of shares, you are not entitled to receive physical delivery of stock certificates or to have shares registered in your name, and you are not considered a registered owner of shares. Therefore, to exercise any rights as an owner of shares, you must rely upon the procedures of DTC and its participants. These procedures are the same as those that apply to any securities that you hold in book entry or “street name” form.

Share Prices

The trading prices of Fund shares in the secondary market may differ in varying degrees from their daily NAVs and can be affected by market forces such as supply and demand, economic conditions and other factors.

A Fund may determine to have the approximate value of its shares, known as the “indicative optimized portfolio value” (“IOPV”), disseminated every fifteen seconds throughout the trading day by the national securities exchange on

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Shareholder Information (cont.)

which the Fund is listed or by other information providers or market data vendors. Any IOPV disseminated is based on the current market value of the securities and cash required to be deposited in exchange for a Creation Unit. Any IOPV disseminated does not necessarily reflect the precise composition of the current portfolio of securities held by a Fund at a particular point in time nor the best possible valuation of the current portfolio. Any IOPV disseminated should not be viewed as a “real-time” update of the NAV, because the IOPV may not be calculated in the same manner as the NAV, which is computed once a day as discussed below. Any IOPV disseminated is generally determined by using current market quotations and/or price quotations obtained from broker-dealers that may trade in the portfolio securities held by the Funds. The quotations of certain Fund holdings may not be updated during U.S. trading hours if such holdings do not trade in the U.S. The Funds are not involved in, or responsible for, the calculation or dissemination of an IOPV and make no warranty as to the accuracy of any disseminated IOPV.

Determination of Net Asset Value

Each Fund’s NAV is determined daily as of the close of regular trading on the New York Stock Exchange (“NYSE”), normally 4:00 p.m. Eastern time, on each day the NYSE is open for trading, based on prices at the time of closing provided that any U.S. fixed-income assets may be valued as of the announced closing time for trading in fixed-income instruments on any day that the Securities Industry and Financial Markets Association announces an early closing time. The NAV of a Fund is calculated by dividing the value of all assets of the Fund (including accrued interest and dividends), less all liabilities (including accrued expenses and dividends declared but unpaid), by the total number of the Fund’s shares outstanding.

The investments of the Funds are valued at fair value pursuant to the pricing policy and procedures approved by the Board of Trustees. The Funds’ investments are valued using market quotations when available. The Board of Trustees has designated NTI as the valuation designee pursuant to Rule 2a-5 under the 1940 Act to perform fair value determinations relating to any or all Fund investments. Accordingly, when market quotations are not readily available, are

deemed unreliable, or do not reflect material events occurring between the close of local markets and the time of valuation, NTI values Fund securities at fair value as determined in good faith in accordance with the Funds’ fair value pricing procedures as approved by the Board of Trustees. Such circumstances include periods when trading in a security is suspended, the exchange or market on which a security trades closes early, the trading volume in a security is limited, corporate actions and announcements take place, or regulatory news affecting an issuer is released, such as government approvals. The Board of Trustees oversees NTI in its role as valuation designee in accordance with the requirements of Rule 2a-5 under the 1940 Act. Additionally, the Trust, in its discretion, may make adjustments to the prices of securities held by a Fund if an event occurs after the publication of market values normally used by NTI on behalf of a Fund but before the time as of which the Fund calculates its NAV, depending on the nature and significance of the event, consistent with applicable regulatory guidance and the Trust’s fair value procedures. Other events that can trigger fair valuing of foreign securities include, for example, significant fluctuations in general market indicators, government actions, or natural disasters.

The use of fair valuation involves the risk that the values used by NTI to price a Fund’s investments may be higher or lower than the values used by other investment companies and investors to price the same investments. Fair value pricing involves subjective judgments and it is possible that a fair value determination for a portfolio security may be materially different than the value that could be realized upon the sale of such security. In addition, fair value pricing could result in a difference between the prices used to calculate a Fund’s NAV and the prices used by a Fund’s Underlying Index. This difference may adversely affect the Fund’s ability to track its Underlying Index. Portfolio securities of certain Funds are listed on foreign exchanges, and their values may change on days when shareholders will not be able to purchase or sell Fund shares.

Security prices are generally provided by independent pricing services. Portfolio securities listed or traded on domestic securities exchanges or the Nasdaq/NMS, including dollar-dominated foreign securities or American Depositary Receipts (“ADRs”), are valued at the closing price or last sale price reported on the exchange or system where

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Shareholder Information (cont.)

the security is principally traded. The closing price for securities traded on the Nasdaq/NMS is the Nasdaq Official Closing Price (“NOCP”). If there have been no sales for that day on the exchange or system where the security is principally traded, then the value is determined with reference to the last sale price, or the NOCP, if applicable, on any other exchange or system. If there have been no sales of the security for that day on any exchange or system, the security is valued at fair value pursuant to the Trust’s fair value procedures.

Securities that are traded regularly in the over-the-counter market (other than the Nasdaq/NMS), including securities listed on exchanges but primarily traded over-the-counter, are valued on the basis of bid quotes or the mean between the bid and asked quotes based upon quotes furnished by one or more broker-dealers or market makers for those securities. Securities that may be traded over-the-counter include equity securities, fixed-income securities, non-exchange-listed foreign securities, and certain derivative instruments. Fixed income securities may be valued using prices provided directly from one or more broker-dealers, market makers, or independent third-party pricing services which may use matrix pricing and valuation models, as well as recent market transactions for the same or similar assets, to derive values when such prices are believed to reflect fair market values of such securities. Such prices may be determined by taking into account securities prices, yields, maturities, call features, ratings, prepayment speeds, credit risks, cash flows, institutional size trading in similar groups of securities and developments related to specific securities. Fixed-income securities maturing within a relatively short period, less than 60 days, are valued at amortized cost when fair value is approximated.

Foreign equity securities are generally priced at the closing price or last sales price reported on the foreign exchange on which they are principally traded. If there have been no sales for that day on the primary exchange, then the value is determined with reference to the last sale price on any other exchange. If there have been no sales of the security for that day on any exchange, the security will be valued at fair value pursuant to the Trust’s fair value procedures. Spot and forward foreign currency exchange contracts generally are valued using an independent pricing service. The

value of assets denominated in foreign currencies is converted into U.S. dollars using exchange rates deemed appropriate by NTI as investment adviser. Any use of a different rate from the rates used by the Index Provider to a Fund’s Underlying Index may adversely affect the Fund’s ability to track its Underlying Index.

Exchange-traded financial futures and options thereon are valued at the settlement price as established by the exchange on which they are traded. Over-the-counter options are valued at broker-provided bid prices, as are swaps. The foregoing prices may be obtained from one or more independent pricing services or, as needed or applicable, independent broker-dealers. If there was no sale on that day, and for other non-exchange traded derivatives, the contract is valued at fair value pursuant to the Trust’s fair value procedures.

Each Fund relies on various sources to calculate its NAV. The ability of the Funds’ administrator to calculate the NAV per share of the Funds is subject to operational risks associated with processing or human errors, systems or technology failures, and errors caused by third party service providers, data sources, or trading counterparties. Such failures may result in delays in the calculation of the Funds’ NAVs and/or the inability to calculate NAV over extended time periods. The Funds may be unable to recover any losses associated with such failures, and it may be necessary for alternative procedures to be followed to price portfolio securities when determining the Funds’ NAVs.

Distribution and Service Plan

The Trust has adopted a Distribution and Service Plan (the “Plan”) pursuant to Rule 12b-1 under the 1940 Act that allows each Fund to pay distribution and other fees for the sale and distribution of its shares. Because these fees would be paid out of each Fund’s assets on an on-going basis, over time these fees would increase the cost of your investment and may cost you more than paying other types of sales charges. Payments to financial intermediaries under the Plan are tied directly to their own out-of-pocket expenses. As of this date, the Plan has not been implemented with respect to the Funds. The Plan may not be implemented without further Board of Trustees approval. The maximum distribution fee is 0.25% of each Fund’s average net assets

238

Shareholder Information (cont.)

under the Plan. The Funds do not expect to pay any 12b-1 fees during the current and next fiscal years.

Dividends and Distributions

Dividends from net investment income, including any net foreign currency gains, are generally declared and paid by each Fund according to the following schedule:

	Dividends from Net Investment Income:
Fund	Declared and Paid Quarterly	Declared and Paid Monthly
FlexShares® US Quality Low Volatility Index Fund	✓
FlexShares® Developed Markets ex-US Quality Low Volatility Index Fund	✓
FlexShares® Emerging Markets Quality Low Volatility Index Fund	✓
FlexShares® Morningstar US Market Factor Tilt Index Fund	✓
FlexShares® Morningstar Developed Markets ex-US Factor Tilt Index Fund	✓
FlexShares® Morningstar Emerging Markets Factor Tilt Index Fund	✓

	Dividends from Net Investment Income:
Fund	Declared and Paid Quarterly	Declared and Paid Monthly
FlexShares® US Quality Large Cap Index Fund	✓
FlexShares® STOXX® US ESG Select Index Fund	✓
FlexShares® STOXX® Global ESG Select Index Fund	✓
FlexShares® ESG & Climate US Large Cap Core Index Fund	✓
FlexShares® ESG & Climate Developed Markets ex-US Core Index Fund	✓
FlexShares® ESG & Climate Emerging Markets Core Index Fund	✓
FlexShares® Morningstar Global Upstream Natural Resources Index Fund	✓
FlexShares® STOXX® Global Broad Infrastructure Index Fund	✓
FlexShares® Global Quality Real Estate Index Fund	✓
FlexShares® Real Assets Allocation Index Fund	✓

239

Shareholder Information (cont.)

	Dividends from Net Investment Income:
Fund	Declared and Paid Quarterly	Declared and Paid Monthly
FlexShares® Quality Dividend Index Fund	✓
FlexShares® Quality Dividend Defensive Index Fund	✓
FlexShares® International Quality Dividend Index Fund	✓
FlexShares® International Quality Dividend Defensive Index Fund	✓
FlexShares® International Quality Dividend Dynamic Index Fund	✓
FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund		✓
FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund		✓
FlexShares® Disciplined Duration MBS Index Fund		✓
FlexShares® Credit- Scored US Corporate Bond Index Fund		✓

	Dividends from Net Investment Income:
Fund	Declared and Paid Quarterly	Declared and Paid Monthly
FlexShares® Credit- Scored US Long Corporate Bond Index Fund		✓
FlexShares® High Yield Value-Scored Bond Index Fund		✓
FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund		✓

Distributions of net realized securities gains, if any, generally are declared and paid once a year, but the Trust may make distributions on a more frequent basis for the Funds. The Trust reserves the right to declare special distributions if, in its reasonable discretion, such action is necessary or advisable to improve tracking error, to preserve its status as a regulated investment company or to avoid imposition of income or excise taxes on undistributed income or realized gains.

Dividends and other distributions on shares are distributed on a pro rata basis to beneficial owners of such shares. Dividend payments are made through DTC participants to beneficial owners then of record with proceeds received from a Fund. Dividends and securities gains distributions are distributed in U.S. dollars and cannot be automatically reinvested in additional shares of the Funds.

No dividend reinvestment service is provided by the Trust. Broker-dealers may make available the DTC book-entry Dividend Reinvestment Service for use by beneficial owners of the Fund for reinvestment of their dividend distributions. Beneficial owners should contact their broker to determine the availability and costs of the service and the details of participation therein. Brokers may require beneficial owners to adhere to specific procedures and timetables. If this service is available and used, dividend distributions of both income and realized gains will be automatically reinvested in additional whole shares of the Fund purchased in the secondary market.

240

Shareholder Information (cont.)

Tax Considerations

The following is a summary of certain tax considerations that may be relevant to an investor in a Fund. The discussions of the federal tax consequences in this Prospectus are based on the Internal Revenue Code of 1986, as amended (the “Code”), and the regulations issued under it, and court decisions and administrative interpretations, as in effect on the date of this Prospectus. Future legislative or administrative changes or court decisions may significantly alter the statements included herein, and any such changes or decisions may be retroactive. Except where otherwise indicated, the discussion relates to shareholders who are individual United States citizens or residents and is based on current tax law. You should consult your tax advisor for further information regarding federal, state, local and/or foreign tax consequences relevant to your specific situation.

Each Fund has elected and intends to qualify (or if newly organized, intends to elect and qualify) each year as a regulated investment company for federal income tax purposes, and to distribute to shareholders substantially all of its net investment income and net capital gain each year. Except as otherwise noted below, you will generally be subject to federal income tax on a Fund’s distributions to you. For federal income tax purposes, Fund distributions attributable to short-term capital gains and net investment income are taxable to you as ordinary income. Distributions attributable to net capital gain (the excess of net long-term capital gains over net short-term capital losses) of a Fund generally are taxable to you as long-term capital gains. This is true no matter how long you own your shares. The maximum long-term capital gain rate applicable to individuals, estates and trusts is 20%. Every year, you will be provided information detailing the amount of ordinary income and capital gains distributed to your account for the previous year.

Distributions of “qualifying dividends” will also generally be taxable to you at long-term capital gain rates, as long as certain requirements are met. In general, if 95% or more of the gross income of a Fund (other than net capital gain) consists of dividends received from domestic corporations or “qualified” foreign corporations (“qualifying dividends”) and when certain other requirements are met, then all distributions paid by the Fund to individual, trust or estate shareholders will be treated as qualifying dividends. But if

less than 95% of the gross income of a Fund (other than net capital gain) consists of qualifying dividends, then distributions paid by the Fund to individual, trust or estate shareholders will be qualifying dividends only to the extent they are derived from qualifying dividends earned by the Fund. For the lower rates to apply, you must have owned your Fund shares for at least 61 days during the 121-day period beginning on the date that is 60 days before the Fund’s ex-dividend date (and the Fund will need to have met a similar holding period requirement with respect to the shares of the corporation paying the qualifying dividend). The amount of a Fund’s distributions that qualify for this favorable treatment may be reduced as a result of the Fund’s securities lending activities (if any), a high portfolio turnover rate or investments in debt securities or “non-qualified” foreign corporations.

Certain Funds may make distributions to you of “Section 199A dividends” with respect to qualified dividends that it receives with respect to its investments in REITs. A Section 199A dividend is any dividend or part of such dividend that a Fund pays to its shareholders and reports as a Section 199A dividend in written statements furnished to its shareholders. Distributions paid by a Fund that are eligible to be treated as Section 199A dividends for a taxable year may not exceed the “qualified REIT dividends” received by the Fund from REITs reduced by the Fund’s allocable expenses. Section 199A dividends may be taxed to individuals and other non-corporate shareholders at a reduced effective federal income tax rate, provided the shareholder receiving the dividends has satisfied a holding period requirement for the Fund’s shares and satisfied certain other conditions. For the lower rates to apply, you must have owned your Fund shares for at least 46 days during the 91-day period beginning on the date that is 45 days before the Fund’s ex-dividend date, but only to the extent that the shareholder is not under an obligation (under a short-sale or otherwise) to make related payments with respect to positions in substantially similar or related property. For more information, see the discussion in the SAI under “TAXES — Taxation of Income of Certain Financial Instruments, REITS and PFICs.”

U.S. individuals with “modified adjusted gross income” exceeding $200,000 ($250,000 if married and filing jointly) and trusts and estates with income above certain thresholds

241

Shareholder Information (cont.)

will be subject to the Medicare contribution tax on their “net investment income,” which includes interest, dividends and capital gains at a rate of 3.8%.

A portion of distributions paid by a Fund to shareholders who are corporations also may qualify for the dividends-received deduction for corporations, subject to certain holding period requirements and debt financing limitations. The amount of the dividends qualifying for this deduction may, however, be reduced as a result of a Fund’s securities lending activities (if any), by a high portfolio turnover rate or by investments in debt securities or foreign corporations.

Dividends and distributions from each Fund will generally be taxable to you in the tax year in which they are paid, with one exception. Dividends and distributions declared by a Fund in October, November or December and paid in January are taxed as though they were paid by December 31.

Distributions in excess of a Fund’s current and accumulated earnings and profits will, as to each shareholder, be treated as a tax-free return of capital and will reduce the shareholder’s basis in his shares of the Fund (but not below zero). To the extent such distribution exceeds the shareholder’s basis, the distribution will result in a capital gain (if the shareholder holds his shares of the Fund as capital assets) as if the shareholder sold his shares. Such capital gain will be long term capital gain if the shareholder held the shares for more than one year.

The Funds may be subject to foreign withholding taxes with respect to dividends or interest received from sources in foreign countries. If at the close of the taxable year more than 50% in value of a Fund’s assets consists of stock in foreign corporations such Fund will be eligible to make an election to treat a proportionate amount of those taxes as constituting a distribution to each shareholder, which would allow you either: (1) to credit that proportionate amount of taxes against U.S. Federal income tax liability as a foreign tax credit; or (2) to take that amount as an itemized deduction. The Funds not eligible to make this election and eligible Funds that do not make the election will be entitled to deduct such taxes in computing the amounts they are required to distribute.

If you: (a) have provided either an incorrect Social Security Number or taxpayer identification number or no number at all; (b) are subject to withholding by the Internal Revenue Service (“IRS”) for prior failure to properly include on your return payments of interest or dividends; or (c) have failed to certify, when required to do so, that you are not subject to backup withholding or are an “exempt recipient,” then 24% of the dividends and distributions payable to you will be withheld and remitted to the IRS.

The sale or redemption of Fund shares is a taxable event on which a gain or loss may be recognized. The amount of gain or loss is based on the difference between your tax basis in the Fund shares and the amount you receive for them upon disposition. Generally, you will recognize long-term capital gain or loss if you have held your Fund shares for over twelve months at the time you dispose of them. Gains and losses on shares held for twelve months or less will generally constitute short-term capital gains, except that a loss on shares held six months or less will be recharacterized as a long-term capital loss to the extent of any capital gains distributions that you have received on the shares. A loss realized on a sale or exchange of Fund shares may be disallowed under the so-called “wash sale” rules to the extent the shares disposed of are replaced with other shares of that same Fund within a period of 61 days beginning 30 days before and ending 30 days after the shares are disposed of, such as pursuant to a dividend reinvestment in shares of the Fund. If disallowed, the loss will be reflected in an adjustment to the basis of the shares acquired.

The one major exception to the preceding tax principles is that distributions on, and sales, exchanges and redemptions of, shares held in an IRA or other tax-qualified plan will not be currently taxable unless shares are acquired with borrowed funds. Distributions may be taxable upon withdrawal from tax-advantaged accounts.

Except as stated below, you may be subject to state and local taxes on Fund distributions and redemptions. State income taxes may not apply, however, to the portions of each Fund’s distributions, if any, that are attributable to interest on certain types of federal securities or interest on securities issued by the particular state or municipalities within the state.

242

Shareholder Information (cont.)

U.S. Tax Treatment of Foreign Shareholders. Nonresident aliens, foreign corporations and other foreign investors in the Funds will generally be exempt from U.S. federal income tax on Fund distributions attributable to net capital gains. The exemption may not apply, however, if the investment in a Fund is connected to a trade or business of the foreign investor in the United States or if the foreign investor is present in the United States for 183 days or more in a year and certain other conditions are met.

Fund distributions attributable to the other categories of Fund income, such as dividends from companies whose securities are held by a Fund and interest on debt securities, will generally be subject to a 30% withholding tax when paid to foreign shareholders. However, certain interest related dividends and short-term capital gain dividends as designated by a Fund are not subject to this 30% withholding tax if the shareholder provides a properly completed Form W-8BEN or W-8BEN-E, as applicable. The withholding tax may, however, be reduced (and, in some cases, eliminated) under an applicable tax treaty between the United States and a shareholder’s country of residence or incorporation, provided that the shareholder furnishes the Fund with a properly completed Form W-8BEN or W-8BEN-E, as applicable to establish entitlement for these treaty benefits. In addition, the Funds will be required to withhold 30% tax on certain payments to foreign entities that do not meet specified information reporting requirements under the Foreign Account Tax Compliance Act.

Notwithstanding the foregoing, gains from United States Real Property Interests (as defined in the Code) are subject to different rules, as discussed below.

If the Fund is a “qualified investment entity” as defined in the Code, Fund distributions attributable to gains from United States Real Property Interests (“Real Estate Gains”) will be treated as ordinary dividends, subject to withholdings as described above, for foreign shareholders who did not own more than 5% of the outstanding shares of the Fund at any time during the one-year period ending on the date of the distribution. If the Fund is a qualified investment entity, Real Estate Gains distributed are subject to withholding at a rate of up to 21% for foreign shareholders who own more than 5% of the outstanding shares of the Fund at any time during the one-year period ending

on the date of the distribution, and such foreign shareholders may be required to file a U.S. federal income tax return. If a foreign shareholder holds more than 5% of the Fund at any time during the 5-year period ending on the date of disposition or redemption of shares and the Fund is a United States Real Property Holding Corporation (as defined in the Code), the foreign shareholder will be subject to U.S. federal income tax on gain recognized on a sale or redemption of shares and withholding of tax on the proceeds received. Foreign shareholders recognizing such income and gain may be required to file a U.S. federal income tax return.

Foreign corporations recognizing income or gain under these rules may be subject to the U.S. Branch Profits Tax.

Except as described above, a foreign investor will generally not be subject to U.S. tax on gains realized on sales or exchanges of Fund shares unless the investment in the Fund is connected to a trade or business of the investor in the United States or if the investor is present in the United States for 183 days or more in a year and certain other conditions are met. All foreign investors should consult their own tax advisors regarding the tax consequences in their country of residence of an investment in the Fund.

Taxes on Creations and Redemptions of Creation Units. A person who purchases a Creation Unit by exchanging securities in-kind generally will recognize a gain or loss equal to the difference between the market value of the Creation Units at that time, and the purchaser’s aggregate basis in the securities surrendered and any net cash paid. A person who redeems Creation Units and receives securities in-kind from a Fund will generally recognize a gain or loss equal to the difference between the redeemer’s basis in the Creation Units, and the aggregate market value of the securities received and any net cash received. The IRS, however, may assert that a loss realized upon an in-kind exchange of securities for Creation Units or an exchange of Creation Units for securities cannot be deducted currently under the rules governing “wash sales,” or on a basis that there has been no significant change in economic position. Persons effecting in-kind creations or redemptions should consult their own tax adviser with respect to these matters.

243

Shareholder Information (cont.)

Under current federal tax laws, any capital gain or loss realized upon redemption of Creation Units of a Fund is generally treated as long-term capital gain or loss if the Fund’s shares have been held for more than one year and as a short-term capital gain or loss if the Funds shares have been held for one year or less, assuming such Creation Units are held as a capital asset.

If a Fund redeems Creation Units in cash, it may recognize more capital gains than it will if it redeems Creation Units in-kind. There are certain tax requirements that each Fund must follow in order to qualify as a regulated investment company and to avoid federal income taxation. In their efforts to adhere to these requirements, the Funds may have to limit their investment activity in some types of instruments.

Consult Your Tax Professional. Your investment in the Funds could have additional tax consequences. You should consult your tax professional for information regarding all tax consequences applicable to your investments in the Funds. More tax information is provided in the SAI. This short summary is not intended as a substitute for careful tax planning.

Householding

Householding is an option available to certain investors. Householding is a method of delivery, based on the preference of the individual investor, in which a single copy of certain shareholder documents can be delivered to investors who share the same address, even if their accounts are registered under different names. Householding is available through certain broker-dealers. If you are interested in enrolling in householding and receiving a single copy of prospectuses and other shareholder documents, please contact your broker-dealer. If you are currently enrolled in householding and wish to change your householding status, please contact your broker-dealer.

244

Financial Highlights

The financial highlights table is intended to help you understand the following Funds’ financial performance for the past five fiscal years or, if shorter, from commencement of operations through October 31, 2023. Certain information reflects financial results for a single share. This information has been audited by Deloitte & Touche LLP, an independent registered public accounting firm, whose report, along with the financial statements of the following Funds for the period ended October 31, 2023, is included in the annual report of the Funds and is available upon request.

		FlexShares® US Quality Low Volatility Index Fund
		Year ended October 31,			For the period 07/15/19* through 10/31/19
	2023	2022	2021	2020
Net asset value, beginning of period	$50.02	$54.60	$40.93	$40.44	$40.00
PER SHARE
Investment Operations
Net Investment Income(a)	0.88	0.82	0.57	0.64	0.17
Net Realized and Unrealized Gain (Loss)	1.40	(4.70 )	13.69	0.38	0.35
Total from Operations	2.28	(3.88 )	14.26	1.02	0.52
Distributions
Net Investment Income	(0.91 )	(0.70 )	(0.59 )	(0.53 )	(0.08 )
Total from Distributions	(0.91 )	(0.70 )	(0.59 )	(0.53 )	(0.08 )
Net Asset Value, end of period	$51.39	$50.02	$54.60	$40.93	$40.44
Total Return(b)
Net Asset Value(d)	4.56 %	(7.12 )%	35.05 %	2.63 %	1.30 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets(c)
Expenses	0.23 %	0.23 %	0.23 %	0.23 %	0.23 %
Expenses net of reimbursements	0.22 %	0.22 %	0.22 %	0.22 %	0.22 %
Net Investment Income Before Reimbursements	1.70 %	1.58 %	1.17 %	1.55 %	1.45 %
Net Investment Income Net of Reimbursements	1.70 %	1.58 %	1.17 %	1.56 %	1.45 %
Supplemental Data
Portfolio Turnover Rate(b)(e)	51 %	48 %	43 %	47 %	9 %
Net assets, end of period (thousands)	$185,005	$162,569	$161,074	$110,524	$6,067

Commencement of investment operations.

245

Financial Highlights (cont.)

		FlexShares® Developed Markets ex-US Quality Low Volatility Index Fund
		Year ended October 31,			For the period 07/15/19* through 10/31/19
	2023	2022	2021	2020
Net asset value, beginning of period	$22.09	$27.92	$23.48	$25.60	$25.00
PER SHARE
Investment Operations
Net Investment Income(a)	0.73	0.66	0.73	0.64	0.16
Net Realized and Unrealized Gain (Loss)	1.55	(5.71 )	4.43	(2.22 )	0.53
Total from Operations	2.28	(5.05 )	5.16	(1.58 )	0.69
Distributions
Net Investment Income	(0.70 )	(0.78 )	(0.72 )	(0.54 )	(0.09 )
Total from Distributions	(0.70 )	(0.78 )	(0.72 )	(0.54 )	(0.09 )
Net Asset Value, end of period	$23.67	$22.09	$27.92	$23.48	$25.60
Total Return(b)
Net Asset Value(d)	10.16 %	(18.36 )%	22.05 %	(6.24 )%	2.76 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets(c)
Expenses	0.33 %	0.33 %	0.33 %	0.33 %	0.32 %
Expenses net of reimbursements	0.32 %	0.32 %	0.32 %	0.32 %	0.32 %
Net Investment Income Before Reimbursements	2.94 %	2.60 %	2.68 %	2.63 %	2.21 %
Net Investment Income Net of Reimbursements	2.94 %	2.60 %	2.68 %	2.64 %	2.21 %
Supplemental Data
Portfolio Turnover Rate(b)(e)	52 %	56 %	56 %	62 %	14 %
Net assets, end of period (thousands)	$66,263	$61,852	$75,371	$65,747	$5,120

Commencement of investment operations.

246

Financial Highlights (cont.)

		FlexShares® Emerging Markets Quality Low Volatility Index Fund
		Year ended October 31,			For the period 07/15/19* through 10/31/19
	2023	2022	2021	2020
Net asset value, beginning of period	$20.53	$26.41	$23.95	$24.94	$25.00
PER SHARE
Investment Operations
Net Investment Income(a)	0.76	0.67	0.69	0.56	0.23
Net Realized and Unrealized Gain (Loss)	1.02	(5.82 )	2.22	(0.91 )	(0.18 )
Total from Operations	1.78	(5.15 )	2.91	(0.35 )	0.05
Distributions
Net Investment Income	(0.68 )	(0.69 )	(0.45 )	(0.64 )	(0.11 )
Tax Return of Capital	—	(0.04 )	—	—	—
Total from Distributions	(0.68 )	(0.73 )	(0.45 )	(0.64 )	(0.11 )
Net Asset Value, end of period	$21.63	$20.53	$26.41	$23.95	$24.94
Total Return(b)
Net Asset Value(d)	8.52 %	(19.77 )%	12.09 %	(1.41 )%	0.19 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets(c)
Expenses	0.41 %	0.41 %	0.41 %	0.41 %	0.40 %
Expenses net of reimbursements	0.40 %	0.40 %	0.40 %	0.40 %	0.40 %
Net Investment Income Before Reimbursements	3.35 %	2.75 %	2.57 %	2.38 %	3.18 %
Net Investment Income Net of Reimbursements	3.35 %	2.75 %	2.58 %	2.39 %	3.18 %
Supplemental Data
Portfolio Turnover Rate(b)(e)	75 %	53 %	54 %	81 %	12 %
Net assets, end of period (thousands)	$12,980	$8,214	$15,844	$9,578	$4,989

Commencement of investment operations.

247

Financial Highlights (cont.)

	FlexShares® Morningstar US Market Factor Tilt Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$151.07	$178.97	$121.11	$119.52	$110.13
PER SHARE
Investment Operations
Net Investment Income(a)	2.53	2.39	2.08	2.10	1.95
Net Realized and Unrealized Gain (Loss)	6.03	(27.93 )	57.80	1.60	9.33
Total from Operations	8.56	(25.54 )	59.88	3.70	11.28
Distributions
Net Investment Income	(2.45 )	(2.36 )	(2.02 )	(2.11 )	(1.89 )
Total from Distributions	(2.45 )	(2.36 )	(2.02 )	(2.11 )	(1.89 )
Net Asset Value, end of period	$157.18	$151.07	$178.97	$121.11	$119.52
Total Return
Net Asset Value(d)	5.67 %	(14.33 )%	49.68 %	3.28 %	10.41 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.26 %	0.26 %	0.26 %	0.26 %	0.26 %
Expenses net of reimbursements	0.25 %	0.25 %	0.25 %	0.25 %	0.25 %
Net Investment Income Before Reimbursements	1.58 %	1.47 %	1.28 %	1.78 %	1.72 %
Net Investment Income Net of Reimbursements	1.58 %	1.47 %	1.29 %	1.79 %	1.72 %
Supplemental Data
Portfolio Turnover Rate(e)	15 %	14 %	24 %	26 %	28 %
Net assets, end of period (thousands)	$1,336,011	$1,397,408	$1,727,019	$1,174,786	$1,446,137

248

Financial Highlights (cont.)

	FlexShares® Morningstar Developed Markets ex-US Factor Tilt Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$54.48	$73.71	$54.24	$62.67	$59.76
PER SHARE
Investment Operations
Net Investment Income(a)	1.93	1.94	1.71	1.31	1.85
Net Realized and Unrealized Gain (Loss)	5.37	(18.44 )	19.27	(7.88 )	2.89
Total from Operations	7.30	(16.50 )	20.98	(6.57 )	4.74
Distributions
Net Investment Income	(1.62 )	(2.61 )	(1.51 )	(1.86 )	(1.83 )
Total Return of Capital	—	(0.12 )	—	—	—
Total from Distributions	(1.62 )	(2.73 )	(1.51 )	(1.86 )	(1.83 )
Net Asset Value, end of period	$60.16	$54.48	$73.71	$54.24	$62.67
Total Return
Net Asset Value(d)	13.21 %	(22.83 )%	38.79 %	(10.57 )%	8.13 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.40 %	0.40 %	0.40 %	0.40 %	0.40 %
Expenses net of reimbursements	0.39 %	0.39 %	0.39 %	0.39 %	0.39 %
Net Investment Income Before Reimbursements	3.04 %	3.02 %	2.42 %	2.28 %	3.09 %
Net Investment Income Net of Reimbursements	3.04 %	3.02 %	2.42 %	2.28 %	3.09 %
Supplemental Data
Portfolio Turnover Rate(e)	22 %	27 %	29 %	21 %	25 %
Net assets, end of period (thousands)	$469,239	$446,754	$648,638	$499,016	$965,142

249

Financial Highlights (cont.)

	FlexShares® Morningstar Emerging Markets Factor Tilt Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$42.22	$60.79	$48.05	$50.42	$47.92
PER SHARE
Investment Operations
Net Investment Income(a)	1.45	1.86	1.51	1.02	1.49
Net Realized and Unrealized Gain (Loss)	4.36	(18.06 )	12.40	(1.97 )	2.46
Total from Operations	5.81	(16.20 )	13.91	(0.95 )	3.95
Distributions
Net Investment Income	(1.49 )	(2.37 )	(1.17 )	(1.42 )	(1.45 )
Total from Distributions	(1.49 )	(2.37 )	(1.17 )	(1.42 )	(1.45 )
Net Asset Value, end of period	$46.54	$42.22	$60.79	$48.05	$50.42
Total Return
Net Asset Value(d)	13.63 %(f)	(27.32 )%	28.95 %	(1.86 )%	8.29 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.61 %	0.60 %	0.60 %	0.60 %	0.60 %
Expenses net of reimbursements	0.59 %	0.59 %	0.59 %	0.59 %	0.59 %
Net Investment Income Before Reimbursements	2.95 %	3.49 %	2.46 %	2.13 %	2.92 %
Net Investment Income Net of Reimbursements	2.97 %	3.49 %	2.47 %	2.14 %	2.93 %
Supplemental Data
Portfolio Turnover Rate(e)	39 %	34 %	40 %	41 %	45 %
Net assets, end of period (thousands)	$218,724	$206,889	$334,372	$225,847	$413,414

250

Financial Highlights (cont.)

	FlexShares® US Quality Large Cap Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$43.17	$50.25	$35.48	$34.69	$33.44
PER SHARE
Investment Operations
Net Investment Income(a)	0.67	0.61	0.50	0.62	0.68
Net Realized and Unrealized Gain (Loss)	3.43	(7.11 )	14.76	0.76	1.29
Total from Operations	4.10	(6.50 )	15.26	1.38	1.97
Distributions
Net Investment Income	(0.66 )	(0.58 )	(0.49 )	(0.59 )	(0.72 )
Total from Distributions	(0.66 )	(0.58 )	(0.49 )	(0.59 )	(0.72 )
Net Asset Value, end of period	$46.61	$43.17	$50.25	$35.48	$34.69
Total Return
Net Asset Value(d)	9.54 %	(12.98 )%	43.21 %	4.13 %	6.04 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.26 %	0.30 %	0.33 %	0.33 %	0.33 %
Expenses net of reimbursements	0.25 %	0.30 %	0.32 %	0.32 %	0.32 %
Net Investment Income Before Reimbursements	1.44 %	1.31 %	1.11 %	1.77 %	2.04 %
Net Investment Income Net of Reimbursements	1.44 %	1.31 %	1.11 %	1.77 %	2.05 %
Supplemental Data
Portfolio Turnover Rate(e)	20 %	22 %	30 %	48 %	69 %
Net assets, end of period (thousands)	$146,806	$127,350	$144,475	$71,842	$51,171

251

Financial Highlights (cont.)

	FlexShares® STOXX® US ESG Select Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$92.96	$112.73	$79.16	$72.29	$64.33
PER SHARE
Investment Operations
Net Investment Income(a)	1.32	1.22	1.26	1.27	1.21
Net Realized and Unrealized Gain (Loss)	9.71	(19.75 )	33.50	6.81	7.83
Total from Operations	11.03	(18.53 )	34.76	8.08	9.04
Distributions
Net Investment Income	(1.27 )	(1.24 )	(1.19 )	(1.21 )	(1.08 )
Total from Distributions	(1.27 )	(1.24 )	(1.19 )	(1.21 )	(1.08 )
Net Asset Value, end of period	$102.72	$92.96	$112.73	$79.16	$72.29
Total Return
Net Asset Value(d)	11.91 %	(16.51 )%	44.15 %	11.40 %	14.21 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.33 %	0.33 %	0.33 %	0.33 %	0.33 %
Expenses net of reimbursements	0.32 %	0.32 %	0.32 %	0.32 %	0.32 %
Net Investment Income Before Reimbursements	1.30 %	1.20 %	1.25 %	1.67 %	1.78 %
Net Investment Income Net of Reimbursements	1.30 %	1.20 %	1.26 %	1.68 %	1.79 %
Supplemental Data
Portfolio Turnover Rate(e)	28 %	46 %	40 %	66 %	75 %
Net assets, end of period (thousands)	$166,925	$171,980	$191,643	$89,052	$56,024

252

Financial Highlights (cont.)

	FlexShares® STOXX® Global ESG Select Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$117.54	$148.57	$106.02	$101.77	$91.61
PER SHARE
Investment Operations
Net Investment Income(a)	2.42	2.24	2.03	1.72	2.05
Net Realized and Unrealized Gain (Loss)	14.27	(30.82 )	42.38	4.26	10.12
Total from Operations	16.69	(28.58 )	44.41	5.98	12.17
Distributions
Net Investment Income	(2.22 )	(2.45 )	(1.86 )	(1.73 )	(2.01 )
Total from Distributions	(2.22 )	(2.45 )	(1.86 )	(1.73 )	(2.01 )
Net Asset Value, end of period	$132.01	$117.54	$148.57	$106.02	$101.77
Total Return
Net Asset Value(d)	14.17 %	(19.35 )%	42.10 %	6.03 %	13.49 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.43 %	0.43 %	0.43 %	0.43 %	0.43 %
Expenses net of reimbursements	0.42 %	0.42 %	0.42 %	0.42 %	0.42 %
Net Investment Income Before Reimbursements	1.82 %	1.69 %	1.50 %	1.66 %	2.15 %
Net Investment Income Net of Reimbursements	1.83 %	1.69 %	1.51 %	1.66 %	2.16 %
Supplemental Data
Portfolio Turnover Rate(e)	35 %	54 %	48 %	58 %	66 %
Net assets, end of period (thousands)	$151,816	$146,925	$185,717	$111,323	$91,590

253

Financial Highlights (cont.)

	FlexShares® ESG & Climate US Large Cap Core Index Fund
		Year ended October 31, 2023	Year ended October 31, 2022	For the period 09/20/21* through 10/31/21
Net asset value, beginning of period		$44.21	$53.39	$50.00
PER SHARE
Investment Operations
Net Investment Income(a)		0.77	0.70	0.06
Net Realized and Unrealized Gain (Loss)		3.35	(9.25 )	3.33
Total from Operations		4.12	(8.55 )	3.39
Distributions
Net Investment Income		(0.72 )	(0.62 )	—
From Net Realized Gains		—	(0.01 )	—
Total from Distributions		(0.72 )	(0.63 )	—
Net Asset Value, end of period		$47.61	$44.21	$53.39
Total Return(b)
Net Asset Value(d)		9.33 %	(16.09 )%	6.78 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets(c)
Expenses		0.10 %	0.10 %	0.09 %
Expenses net of reimbursements		0.09 %	0.09 %	0.09 %
Net Investment Income Before Reimbursements		1.61 %	1.53 %	0.96 %
Net Investment Income Net of Reimbursements		1.61 %	1.53 %	0.96 %
Supplemental Data
Portfolio Turnover Rate(b)(e)		16 %	18 %	— %(g)
Net assets, end of period (thousands)		$36,896	$22,103	$2,669

Commencement of investment operations.

254

Financial Highlights (cont.)

	FlexShares® ESG & Climate Developed Markets ex-US Core Index Fund
		Year ended October 31, 2023	Year ended October 31, 2022	For the period 09/20/21* through 10/31/21
Net asset value, beginning of period		$38.15	$51.19	$50.00
PER SHARE
Investment Operations
Net Investment Income(a)		1.38	1.44	0.16
Net Realized and Unrealized Gain (Loss)		3.31	(13.28 )	1.03
Total from Operations		4.69	(11.84 )	1.19
Distributions
Net Investment Income		(1.19 )	(1.20 )	—
Total from Distributions		(1.19 )	(1.20 )	—
Net Asset Value, end of period		$41.65	$38.15	$51.19
Total Return(b)
Net Asset Value(d)		12.08 %	(23.36 )%	2.38 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets(c)
Expenses		0.13 %	0.13 %	0.12 %
Expenses net of reimbursements		0.12 %	0.12 %	0.12 %
Net Investment Income Before Reimbursements		3.09 %	3.35 %	2.72 %
Net Investment Income Net of Reimbursements		3.09 %	3.35 %	2.72 %
Supplemental Data
Portfolio Turnover Rate(b)(e)		32 %	33 %	— %(g)
Net assets, end of period (thousands)		$37,484	$17,169	$5,119

Commencement of investment operations.

255

Financial Highlights (cont.)

	FlexShares® ESG & Climate Emerging Markets Core Index Fund
		Year ended October 31, 2023	For the period 04/20/22* through 10/31/22
Net asset value, beginning of period		$38.68	$50.00
PER SHARE
Investment Operations
Net Investment Income(a)		1.02	0.76
Net Realized and Unrealized Gain (Loss)		3.35	(11.42 )
Total from Operations		4.37	(10.66 )
Distributions
Net Investment Income		(1.05 )	(0.66 )
Total from Distributions		(1.05 )	(0.66 )
Net Asset Value, end of period		$42.00	$38.68
Total Return(b)
Net Asset Value(d)		11.14 %	(21.47 )%
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets(c)
Expenses		0.19 %	0.19 %
Expenses net of reimbursements		0.18 %	0.18 %
Net Investment Income Before Reimbursements		2.27 %	3.15 %
Net Investment Income Net of Reimbursements		2.27 %	3.15 %
Supplemental Data
Portfolio Turnover Rate(b)(e)		36 %	18 %
Net assets, end of period (thousands)		$4,200	$3,868

Commencement of investment operations.

256

Financial Highlights (cont.)

	FlexShares® Morningstar Global Upstream Natural Resources Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$41.35	$38.66	$26.71	$31.40	$31.51
PER SHARE
Investment Operations
Net Investment Income(a)	1.46	1.88	1.44	0.89	1.08
Net Realized and Unrealized Gain (Loss)	(3.01 )	2.76	11.72	(4.65 )	(0.09 )
Total from Operations	(1.55 )	4.64	13.16	(3.76 )	0.99
Distributions
Net Investment Income	(1.24 )	(1.95 )	(1.21 )	(0.93 )	(1.10 )
Total from Distributions	(1.24 )	(1.95 )	(1.21 )	(0.93 )	(1.10 )
Net Asset Value, end of period	$38.56	$41.35	$38.66	$26.71	$31.40
Total Return
Net Asset Value(d)	(3.92 )%	12.20 %	49.70 %	(11.87 )%	3.16 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.47 %	0.47 %	0.47 %	0.47 %	0.47 %
Expenses net of reimbursements	0.46 %	0.46 %	0.46 %	0.46 %	0.46 %
Net Investment Income Before Reimbursements	3.48 %	4.48 %	3.95 %	3.03 %	3.40 %
Net Investment Income Net of Reimbursements	3.48 %	4.48 %	3.95 %	3.04 %	3.41 %
Supplemental Data
Portfolio Turnover Rate(e)	27 %	32 %	28 %	29 %	24 %
Net assets, end of period (thousands)	$6,925,286	$6,834,852	$6,052,710	$2,924,726	$5,510,201

257

Financial Highlights (cont.)

	FlexShares® STOXX® Global Broad Infrastructure Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$48.32	$57.73	$48.10	$52.56	$45.09
PER SHARE
Investment Operations
Net Investment Income(a)	1.40	1.35	1.38	1.25	1.35
Net Realized and Unrealized Gain (Loss)	(0.73 )	(9.27 )	9.57	(4.53 )	7.34
Total from Operations	0.67	(7.92 )	10.95	(3.28 )	8.69
Distributions
Net Investment Income	(1.23 )	(1.49 )	(1.32 )	(1.18 )	(1.22 )
Total from Distributions	(1.23 )	(1.49 )	(1.32 )	(1.18 )	(1.22 )
Net Asset Value, end of period	$47.76	$48.32	$57.73	$48.10	$52.56
Total Return
Net Asset Value(d)	1.24 %	(13.92 )%	22.85 %	(6.23 )%	19.52 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.48 %	0.48 %	0.48 %	0.48 %	0.48 %
Expenses net of reimbursements	0.47 %	0.47 %	0.47 %	0.47 %	0.47 %
Net Investment Income Before Reimbursements	2.74 %	2.51 %	2.45 %	2.51 %	2.73 %
Net Investment Income Net of Reimbursements	2.74 %	2.51 %	2.45 %	2.52 %	2.74 %
Supplemental Data
Portfolio Turnover Rate(e)	12 %	16 %	13 %	13 %	12 %
Net assets, end of period (thousands)	$2,025,181	$2,500,518	$2,643,906	$1,856,596	$1,477,030

258

Financial Highlights (cont.)

	FlexShares® Global Quality Real Estate Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$52.12	$70.35	$50.88	$66.60	$57.96
PER SHARE
Investment Operations
Net Investment Income(a)	1.50	1.67	1.38	1.43	1.76
Net Realized and Unrealized Gain (Loss)	(5.09 )	(17.88 )	19.13	(14.62 )	8.68
Total from Operations	(3.59 )	(16.21 )	20.51	(13.19 )	10.44
Distributions
Net Investment Income	(1.48 )	(1.99 )	(1.04 )	(2.50 )	(1.80 )
Tax Return of Capital	—	(0.03 )	—	(0.03 )	—
Total from Distributions	(1.48 )	(2.02 )	(1.04 )	(2.53 )	(1.80 )
Net Asset Value, end of period	$47.05	$52.12	$70.35	$50.88	$66.60
Total Return
Net Asset Value(d)	(7.16 )%	(23.51 )%	40.58 %	(20.29 )%	18.37 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.46 %	0.46 %	0.46 %	0.46 %	0.46 %
Expenses net of reimbursements	0.45 %	0.45 %	0.45 %	0.45 %	0.45 %
Net Investment Income Before Reimbursements	2.83 %	2.63 %	2.16 %	2.53 %	2.80 %
Net Investment Income Net of Reimbursements	2.83 %	2.63 %	2.17 %	2.54 %	2.81 %
Supplemental Data
Portfolio Turnover Rate(e)	49 %	54 %	52 %	56 %	53 %
Net assets, end of period (thousands)	$244,673	$328,381	$418,597	$264,574	$376,264

259

Financial Highlights (cont.)

	FlexShares® Real Assets Allocation Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$28.86	$33.67	$25.72	$30.30	$26.45
PER SHARE
Investment Operations
Net Investment Income(a)	0.73	0.93	0.83	0.86	0.76
Net Realized and Unrealized Gain (Loss)	(1.21 )	(4.72 )	7.78	(4.58 )	3.85
Total from Operations	(0.48 )	(3.79 )	8.61	(3.72 )	4.61
Distributions
Net Investment Income	(0.76 )	(1.02 )	(0.66 )	(0.86 )	(0.76 )
Total from Distributions	(0.76 )	(1.02 )	(0.66 )	(0.86 )	(0.76 )
Net Asset Value, end of period	$27.62	$28.86	$33.67	$25.72	$30.30
Total Return
Net Asset Value(d)	(1.78 )%	(11.49 )%	33.66 %	(12.45 )%	17.69 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.57 %(h)	0.58 %(h)	0.58 %(h)	0.58 %(h)	0.58 %(h)
Expenses net of reimbursements	0.10 %(h)	0.11 %(h)	0.12 %(h)	0.11 %(h)	0.11 %(h)
Net Investment Income Before Reimbursements	1.96 %	2.40 %	2.07 %	2.65 %	2.22 %
Net Investment Income Net of Reimbursements	2.42 %	2.86 %	2.53 %	3.11 %	2.69 %
Supplemental Data
Portfolio Turnover Rate(e)	11 %	7 %	40 %	14 %	4 %
Net assets, end of period (thousands)	$16,573	$28,865	$30,300	$4,502	$11,361

260

Financial Highlights (cont.)

	FlexShares® Quality Dividend Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$52.28	$58.35	$43.40	$46.33	$44.53
PER SHARE
Investment Operations
Net Investment Income(a)	1.36	1.25	1.16	1.24	1.24
Net Realized and Unrealized Gain (Loss)	2.05	(6.05 )	14.89	(2.67 )	2.29
Total from Operations	3.41	(4.80 )	16.05	(1.43 )	3.53
Distributions
Net Investment Income	(1.28 )	(1.27 )	(1.10 )	(1.25 )	(1.19 )
From Net Realized Gains	—	—	—	(0.25 )	(0.54 )
Total from Distributions	(1.28 )	(1.27 )	(1.10 )	(1.50 )	(1.73 )
Net Asset Value, end of period	$54.41	$52.28	$58.35	$43.40	$46.33
Total Return
Net Asset Value(d)	6.52 %	(8.29 )%	37.27 %	(2.98 )%	8.45 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.38 %	0.38 %	0.38 %	0.38 %	0.38 %
Expenses net of reimbursements	0.37 %	0.37 %	0.37 %	0.37 %	0.37 %
Net Investment Income Before Reimbursements	2.45 %	2.24 %	2.16 %	2.79 %	2.80 %
Net Investment Income Net of Reimbursements	2.45 %	2.24 %	2.16 %	2.79 %	2.81 %
Supplemental Data
Portfolio Turnover Rate(e)	51 %	40 %	51 %	75 %	95 %
Net assets, end of period (thousands)	$1,478,273	$1,522,730	$1,642,545	$1,265,177	$1,707,344

261

Financial Highlights (cont.)

	FlexShares® Quality Dividend Defense Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$50.61	$56.01	$42.61	$46.25	$44.46
PER SHARE
Investment Operations
Net Investment Income(a)	1.29	1.16	1.09	1.21	1.22
Net Realized and Unrealized Gain (Loss)	2.66	(5.35 )	13.39	(3.28 )	3.35
Total from Operations	3.95	(4.19 )	14.48	(2.07 )	4.57
Distributions
Net Investment Income	(1.24 )	(1.21 )	(1.08 )	(1.21 )	(1.14 )
From Net Realized Gains	—	—	—	(0.36 )	(1.64 )
Total from Distributions	(1.24 )	(1.21 )	(1.08 )	(1.57 )	(2.78 )
Net Asset Value, end of period	$53.32	$50.61	$56.01	$42.61	$46.25
Total Return
Net Asset Value(d)	7.82 %	(7.53 )%	34.28 %	(4.45 )%	11.40 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.38 %	0.38 %	0.38 %	0.38 %	0.38 %
Expenses net of reimbursements	0.37 %	0.37 %	0.37 %	0.37 %	0.37 %
Net Investment Income Before Reimbursements	2.39 %	2.16 %	2.10 %	2.77 %	2.76 %
Net Investment Income Net of Reimbursements	2.40 %	2.16 %	2.11 %	2.77 %	2.76 %
Supplemental Data
Portfolio Turnover Rate(e)	51 %	47 %	57 %	76 %	91 %
Net assets, end of period (thousands)	$313,231	$345,444	$448,058	$411,173	$450,963

262

Financial Highlights (cont.)

	FlexShares® International Quality Dividend Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$18.47	$25.77	$20.15	$23.06	$22.37
PER SHARE
Investment Operations
Net Investment Income(a)	1.12	1.15	0.97	0.79	1.13
Net Realized and Unrealized Gain (Loss)	2.14	(7.23 )	5.55	(2.86 )	0.70
Total from Operations	3.26	(6.08 )	6.52	(2.07 )	1.83
Distributions
Net Investment Income	(1.03 )	(1.22 )	(0.90 )	(0.84 )	(1.14 )
Total from Distributions	(1.03 )	(1.22 )	(0.90 )	(0.84 )	(1.14 )
Net Asset Value, end of period	$20.70	$18.47	$25.77	$20.15	$23.06
Total Return
Net Asset Value(d)	17.45 %	(24.11 )%	32.42 %	(8.94 )%	8.41 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.49 %	0.48 %	0.48 %	0.48 %	0.48 %
Expenses net of reimbursements	0.47 %	0.47 %	0.47 %	0.47 %	0.47 %
Net Investment Income Before Reimbursements	5.13 %	5.11 %	3.80 %	3.68 %	4.98 %
Net Investment Income Net of Reimbursements	5.14 %	5.11 %	3.81 %	3.68 %	4.98 %
Supplemental Data
Portfolio Turnover Rate(e)	49 %	69 %	68 %	74 %	71 %
Net assets, end of period (thousands)	$498,876	$432,097	$616,007	$453,477	$774,685

263

Financial Highlights (cont.)

	FlexShares® International Quality Dividend Defensive Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$17.63	$23.82	$19.16	$21.87	$21.39
PER SHARE
Investment Operations
Net Investment Income(a)	0.93	0.99	0.93	0.74	1.09
Net Realized and Unrealized Gain (Loss)	1.32	(6.14 )	4.62	(2.70 )	0.51
Total from Operations	2.25	(5.15 )	5.55	(1.96 )	1.60
Distributions
Net Investment Income	(0.95 )	(1.04 )	(0.89 )	(0.75 )	(1.12 )
Total from Distributions	(0.95 )	(1.04 )	(0.89 )	(0.75 )	(1.12 )
Net Asset Value, end of period	$18.93	$17.63	$23.82	$19.16	$21.87
Total Return
Net Asset Value(d)	12.54 %	(22.06 )%	29.03 %	(8.92 )%	7.66 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.48 %	0.48 %	0.48 %	0.48 %	0.48 %
Expenses net of reimbursements	0.47 %	0.47 %	0.47 %	0.47 %	0.47 %
Net Investment Income Before Reimbursements	4.67 %	4.62 %	3.91 %	3.65 %	5.02 %
Net Investment Income Net of Reimbursements	4.67 %	4.62 %	3.92 %	3.66 %	5.03 %
Supplemental Data
Portfolio Turnover Rate(e)	67 %	65 %	65 %	75 %	63 %
Net assets, end of period (thousands)	$26,503	$40,545	$71,459	$59,404	$78,719

264

Financial Highlights (cont.)

	FlexShares® International Quality Dividend Dynamic Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$21.31	$30.39	$22.38	$24.94	$23.51
PER SHARE
Investment Operations
Net Investment Income(a)	1.28	1.45	1.28	0.70	1.05
Net Realized and Unrealized Gain (Loss)	2.91	(9.01 )	7.63	(2.45 )	1.52
Total from Operations	4.19	(7.56 )	8.91	(1.75 )	2.57
Distributions
Net Investment Income	(1.16 )	(1.52 )	(0.90 )	(0.81 )	(1.14 )
Total from Distributions	(1.16 )	(1.52 )	(0.90 )	(0.81 )	(1.14 )
Net Asset Value, end of period	$24.34	$21.31	$30.39	$22.38	$24.94
Total Return
Net Asset Value(d)	19.39 %	(25.48 )%	39.87 %	(6.99 )%	11.30 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.48 %	0.48 %	0.48 %	0.48 %	0.48 %
Expenses net of reimbursements	0.47 %	0.47 %	0.47 %	0.47 %	0.47 %
Net Investment Income Before Reimbursements	4.96 %	5.49 %	4.24 %	2.90 %	4.36 %
Net Investment Income Net of Reimbursements	4.96 %	5.49 %	4.25 %	2.91 %	4.37 %
Supplemental Data
Portfolio Turnover Rate(e)	78 %	74 %	72 %	85 %	88 %
Net assets, end of period (thousands)	$65,714	$61,788	$75,975	$22,376	$47,391

265

Financial Highlights (cont.)

	FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$23.58	$26.38	$25.73	$24.58	$23.81
PER SHARE
Investment Operations
Net Investment Income(a)	0.96	1.72	1.09	0.33	0.46
Net Realized and Unrealized Gain (Loss)	(0.52 )	(2.83 )	0.68	1.09	0.79
Total from Operations	0.44	(1.11 )	1.77	1.42	1.25
Distributions
Net Investment Income	(0.85 )	(1.66 )	(1.12 )	(0.27 )	(0.48 )
Tax Return of Capital	—	(0.03 )	—	—	—
Total from Distributions	(0.85 )	(1.69 )	(1.12 )	(0.27 )	(0.48 )
Net Asset Value, end of period	$23.17	$23.58	$26.38	$25.73	$24.58
Total Return
Net Asset Value(d)	1.84 %	(4.44 )%	6.95 %	5.81 %	5.30 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.19 %	0.19 %	0.19 %	0.19 %	0.19 %
Expenses net of reimbursements	0.18 %	0.18 %	0.18 %	0.18 %	0.18 %
Net Investment Income Before Reimbursements	4.08 %	6.82 %	4.14 %	1.33 %	1.89 %
Net Investment Income Net of Reimbursements	4.08 %	6.83 %	4.15 %	1.33 %	1.89 %
Supplemental Data
Portfolio Turnover Rate(e)	63 %	116 %	53 %	71 %	52 %
Net assets, end of period (thousands)	$1,927,923	$2,157,939	$1,437,584	$1,429,491	$1,178,722

266

Financial Highlights (cont.)

	FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$23.63	$28.02	$27.34	$25.50	$23.95
PER SHARE
Investment Operations
Net Investment Income(a)	1.01	1.83	1.16	0.36	0.44
Net Realized and Unrealized Gain (Loss)	(1.01 )	(4.35 )	0.70	1.76	1.59
Total from Operations	0.00	(2.52 )	1.86	2.12	2.03
Distributions
Net Investment Income	(0.87 )	(1.84 )	(1.18 )	(0.28 )	(0.48 )
Tax Return of Capital	—	(0.03 )	—	—	—
Total from Distributions	(0.87 )	(1.87 )	(1.18 )	(0.28 )	(0.48 )
Net Asset Value, end of period	$22.76	$23.63	$28.02	$27.34	$25.50
Total Return
Net Asset Value(d)	(0.11 )%	(9.46 )%	6.88 %	8.39 %	8.53 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.19 %	0.19 %	0.19 %	0.19 %	0.19 %
Expenses net of reimbursements	0.18 %	0.18 %	0.18 %	0.18 %	0.18 %
Net Investment Income Before Reimbursements	4.26 %	6.98 %	4.17 %	1.35 %	1.77 %
Net Investment Income Net of Reimbursements	4.27 %	6.98 %	4.17 %	1.35 %	1.78 %
Supplemental Data
Portfolio Turnover Rate(e)	52 %	80 %	46 %	66 %	41 %
Net assets, end of period (thousands)	$811,550	$643,886	$714,479	$596,095	$557,185

267

Financial Highlights (cont.)

	FlexShares® Disciplined Duration MBS Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$20.04	$23.42	$24.10	$23.55	$22.74
PER SHARE
Investment Operations
Net Investment Income(a)	0.55	0.26	0.09	0.37	0.61
Net Realized and Unrealized Gain (Loss)	(0.34 )	(3.07 )	(0.16 )	0.85	1.03
Total from Operations	0.21	(2.81 )	(0.07 )	1.22	1.64
Distributions
Net Investment Income	(0.66 )	(0.57 )	(0.61 )	(0.67 )	(0.83 )
Total from Distributions	(0.66 )	(0.57 )	(0.61 )	(0.67 )	(0.83 )
Net Asset Value, end of period	$19.59	$20.04	$23.42	$24.10	$23.55
Total Return
Net Asset Value(d)	0.98 %	(12.16 )%	(0.28 )%	5.19 %	7.36 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.21 %	0.21 %	0.21 %	0.21 %	0.21 %
Expenses net of reimbursements	0.20 %	0.20 %	0.20 %	0.20 %	0.20 %
Net Investment Income Before Reimbursements	2.70 %	1.19 %	0.35 %	1.54 %	2.64 %
Net Investment Income Net of Reimbursements	2.70 %	1.19 %	0.36 %	1.54 %	2.65 %
Supplemental Data
Portfolio Turnover Rate(e)	46 %	222 %	476 %	175 %	61 %
Net assets, end of period (thousands)	$74,424	$97,189	$111,243	$100,020	$35,330

268

Financial Highlights (cont.)

	FlexShares® Credit-Scored US Corporate Bond Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$45.26	$53.52	$54.70	$52.58	$48.59
PER SHARE
Investment Operations
Net Investment Income(a)	1.74	1.04	0.91	1.32	1.63
Net Realized and Unrealized Gain (Loss)	0.05	(7.83 )	(0.51 )	2.39	3.94
Total from Operations	1.79	(6.79 )	0.40	3.71	5.57
Distributions
Net Investment Income	(1.67 )	(1.06 )	(0.96 )	(1.37 )	(1.58 )
From Net Realized Gains	—	(0.41 )	(0.62 )	(0.22 )	—
Total from Distributions	(1.67 )	(1.47 )	(1.58 )	(1.59 )	(1.58 )
Net Asset Value, end of period	$45.38	$45.26	$53.52	$54.70	$52.58
Total Return
Net Asset Value(d)	3.92 %	(12.91 )%	0.70 %	7.20 %	11.66 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.23 %	0.23 %	0.23 %	0.23 %	0.23 %
Expenses net of reimbursements	0.22 %	0.22 %	0.22 %	0.22 %	0.22 %
Net Investment Income Before Reimbursements	3.74 %	2.11 %	1.68 %	2.46 %	3.20 %
Net Investment Income Net of Reimbursements	3.74 %	2.11 %	1.69 %	2.46 %	3.21 %
Supplemental Data
Portfolio Turnover Rate(e)	121 %	66 %	53 %	62 %	65 %
Net assets, end of period (thousands)	$274,550	$242,139	$315,740	$202,397	$97,275

269

Financial Highlights (cont.)

	FlexShares® Credit-Scored US Long Corporate Bond Index Fund
	Year ended October 31,
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$39.44	$60.85	$61.81	$57.84	$48.04
PER SHARE
Investment Operations
Net Investment Income(a)	2.14	1.93	1.90	1.99	2.11
Net Realized and Unrealized Gain (Loss)	(1.33 )	(20.48 )	1.22	3.90	9.89
Total from Operations	0.81	(18.55 )	3.12	5.89	12.00
Distributions
Net Investment Income	(2.15 )	(1.92 )	(1.88 )	(1.92 )	(2.20 )
From Net Realized Gains	—	(0.94 )	(2.20 )	—	—
Total from Distributions	(2.15 )	(2.86 )	(4.08 )	(1.92 )	(2.20 )
Net Asset Value, end of period	$38.10	$39.44	$60.85	$61.81	$57.84
Total Return
Net Asset Value(d)	1.59 %(i)	(31.58 )%	5.14 %	10.34 %	25.57 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets
Expenses	0.23 %	0.23 %	0.23 %	0.23 %	0.23 %
Expenses net of reimbursements	0.22 %	0.22 %	0.22 %	0.22 %	0.22 %
Net Investment Income Before Reimbursements	5.01 %	3.86 %	3.13 %	3.27 %	4.06 %
Net Investment Income Net of Reimbursements	5.02 %	3.86 %	3.14 %	3.28 %	4.07 %
Supplemental Data
Portfolio Turnover Rate(e)	103 %	58 %	88 %	74 %	44 %
Net assets, end of period (thousands)	$28,575	$35,498	$60,855	$46,360	$17,352

270

Financial Highlights (cont.)

	FlexShares® High Yield Value-Scored Bond Index Fund
	Year ended October 31,				2019
	2023	2022	2021	2020	2019
Net asset value, beginning of period	$40.09	$49.58	$46.25	$47.85	$48.84
PER SHARE
Investment Operations
Net Investment Income(a)	3.57	2.98	2.67	3.12	2.67
Net Realized and Unrealized Gain (Loss)	(1.40 )	(9.24 )	3.42	(1.77 )	0.78
Total from Operations	2.17	(6.26 )	6.09	1.35	3.45
Distributions
Net Investment Income	(3.52 )	(2.86 )	(2.76 )	(2.95 )	(3.57 )
From Net Realized Gains	—	(0.37 )	—	—	—
Tax Return of Capital	—	—	—	—	(0.87 )
Total from Distributions	(3.52 )	(3.23 )	(2.76 )	(2.95 )	(4.44 )
Net Asset Value, end of period	$38.74	$40.09	$49.58	$46.25	$47.85
Total Return
Net Asset Value(d)	5.45 %(j)	(13.06 )%	13.38 %	3.07 %	7.48 %
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets(c)
Expenses	0.38 %	0.38 %	0.38 %	0.38 %	0.38 %
Expenses net of reimbursements	0.37 %	0.37 %	0.37 %	0.37 %	0.37 %
Net Investment Income Before Reimbursements	8.90 %	6.81 %	5.40 %	6.78 %	5.56 %
Net Investment Income Net of Reimbursements	8.91 %	6.81 %	5.40 %	6.78 %	5.57 %
Supplemental Data
Portfolio Turnover Rate(e)	167 %	146 %	128 %	95 %	44 %
Net assets, end of period (thousands)	$1,222,307	$887,945	$575,184	$189,623	$100,480

271

Financial Highlights (cont.)

	FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund
		Year ended October 31, 2023	Year ended October 31, 2022	For the period 09/20/21* through 10/31/21
Net asset value, beginning of period		$38.59	$49.35	$50.00
PER SHARE
Investment Operations
Net Investment Income(a)		1.61	1.07	0.10
Net Realized and Unrealized Gain (Loss)		(0.62 )	(10.68 )	(0.75 )
Total from Operations		0.99	(9.61 )	(0.65 )
Distributions
Net Investment Income		(1.62 )	(1.15 )	—
Total from Distributions		(1.62 )	(1.15 )	—
Net Asset Value, end of period		$37.96	$38.59	$49.35
Total Return(b)
Net Asset Value(d)		2.41 %	(19.73 )%	(1.32 )%
RATIOS/SUPPLEMENT DATA
Ratios to Average Net Assets(c)
Expenses		0.13 %	0.13 %	0.12 %
Expenses net of reimbursements		0.12 %	0.12 %	0.12 %
Net Investment Income Before Reimbursements		4.00 %	2.41 %	1.81 %
Net Investment Income Net of Reimbursements		4.00 %	2.41 %	1.81 %
Supplemental Data
Portfolio Turnover Rate(b)(e)		87 %	66 %	8 %
Net assets, end of period (thousands)		$24,672	$23,156	$49,347

Commencement of investment operations.

(a)

Net investment income per share is based on average shares outstanding.

(b)

Not annualized for periods less than one year.

(c)

Annualized for periods less than one year.

(d)

Net asset value total return is calculated assuming an initial investment made at the net asset value at the beginning of the period, reinvestment of all dividends and distributions at net asset value during the period and redemption on the last day of the period at adjusted net asset value.

(e)

In-kind transactions are not included in portfolio turnover calculations.

(f)

Northern Trust Investments, Inc. voluntarily reimbursed expenses of the Fund in the amount of approximately $16,693. Total return excluding the voluntary reimbursement would have been 13.62%.

(g)

Less than 0.5%.

(h)

The Fund indirectly bears its proportionate share of fees and expenses incurred by the Underlying Fund(s) in which the Fund is invested. This ratio does not include these indirect fees and expenses.

(i)

Northern Trust Investments, Inc. voluntarily reimbursed expenses of the Fund in the amount of approximately $2,167. Total return excluding the voluntary reimbursement would have been 1.59%.

(j)

Northern Trust Investments, Inc. voluntarily reimbursed expenses of the Fund in the amount of approximately $84,821. Total return excluding the voluntary reimbursement would have been 5.44%

272

More Information About Underlying Indexes and Index Providers

Morningstar, Inc. (“Morningstar”), a leading provider of investment research in North America, Europe, Australia and Asia, offers an extensive line of Internet-, software- and print-based products and services to individuals, financial advisors and institutions. Morningstar has developed and maintains a wide variety of global equity, fixed income and commodity indexes, including the Morningstar® Global Upstream Natural Resources IndexSM, the Morningstar® US Market Factor Tilt IndexSM, the Morningstar® Developed Markets ex-US Factor Tilt IndexSM and the Morningstar® Emerging Markets Factor Tilt IndexSM (the “Underlying Indexes”). All Morningstar® Indexes, including the Underlying Indexes, are rooted in Morningstar’s proprietary research and are created and maintained using transparent, rules-based methodologies. The words/phrases, “Morningstar®”, “Global Upstream Natural Resources IndexSM”, “US Market Factor Tilt IndexSM”, “Developed Markets ex-US Factor Tilt IndexSM” and “Emerging Markets Factor Tilt IndexSM”, are all service marks of Morningstar.

* * *

The iBoxx 3-Year Target Duration TIPS Index and iBoxx 5-Year Target Duration TIPS Index are each the property of S&P Dow Jones Indices LLC or its affiliates (“SPDJI”) and have been licensed for use in connection the FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund and the FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund, respectively.

SPDJI is the index provider of each of the iBoxx Target Duration TIPS Indexes. SPDJI is a leading, global financial information services company. The company provides independent data, valuations and trade processing across all asset classes in order to enhance transparency, reduce risk and improve operational efficiency. Its client base includes the most significant institutional participants in the financial marketplace. S&P®, S&P 500®, US 500, The 500, iBoxx®, iTraxx® and CDX® are trademarks of S&P Global, Inc. or its affiliates (“S&P”); Dow Jones® is a registered trademark of Dow Jones Trademark Holdings LLC (“Dow Jones”).

* * *

The Northern Trust Quality Low Volatility IndexSM, Northern Trust Developed Markets ex-US Quality Low Volatility

IndexSM, Northern Trust Emerging Markets Quality Low Volatility IndexSM, Northern Trust Quality Large Cap IndexSM, Northern Trust ESG & Climate U.S. Large Cap Core IndexSM, Northern Trust ESG & Climate Developed Markets ex-US Core IndexSM, Northern Trust ESG & Climate Emerging Markets Core IndexSM, Northern Trust Quality Dividend IndexSM, Northern Trust Quality Dividend Defensive IndexSM, Northern Trust International Quality Dividend IndexSM, Northern Trust International Quality Dividend Dynamic IndexSM, Northern Trust International Quality Dividend Defensive IndexSM, Northern Trust Global Quality Real Estate IndexSM, Northern Trust Real Assets Allocation IndexSM, Northern Trust US Corporate Bond Quality Value IndexSM, Northern Trust US Long Corporate Bond Quality Value IndexSM, Northern Trust High Yield Value-Scored US Corporate Bond IndexSM and Northern Trust ESG & Climate Investment Grade U.S. Corporate Core IndexSM (together the “Northern Trust Indexes”) are each the property of NTI and have been licensed for use by the FlexShares® US Quality Low Volatility Index Fund, FlexShares® Developed Markets ex-US Quality Low Volatility Index Fund, FlexShares® Emerging Markets Quality Low Volatility Index Fund, FlexShares® US Quality Large Cap Index Fund, FlexShares® ESG & Climate US Large Cap Core Index Fund, FlexShares® ESG & Climate Developed Markets ex-US Core Index Fund, FlexShares® ESG & Climate Emerging Markets Core Index Fund, FlexShares® Global Quality Real Estate Index Fund, FlexShares® Real Assets Allocation Index Fund, FlexShares® Quality Dividend Index Fund, FlexShares® Quality Dividend Defensive Index Fund, FlexShares® International Quality Dividend Index Fund, FlexShares® International Quality Dividend Defensive Index Fund, FlexShares® International Quality Dividend Dynamic Index Fund, FlexShares® Credit-Scored US Corporate Bond Index Fund, FlexShares® Credit-Scored US Long Corporate Bond Index Fund, FlexShares® High Yield Value-Scored Bond Index Fund and FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund (together the “Funds”), respectively.

NTI is the index provider of each of the Northern Trust Indexes and serves as the Investment Adviser of the Funds. NTI has adopted policies and procedures designed to minimize or eliminate potential conflicts of interest; prevent

273

More Information About Underlying Indexes and Index Providers (cont.)

certain persons from having any advantage over other market participants with respect to prior knowledge of companies that may be added to, or deleted from, a Northern Trust Index or from the portfolios of any Fund that tracks a Northern Trust Index; and prevent the dissemination or use of non-public information about pending changes to index constituents or methodology.

* * *

STOXX Ltd. is a global index provider, currently calculating a global, comprehensive index family of over 6,000 strictly rules-based and transparent indices. Best known for the leading European equity indices EURO STOXX 50, STOXX Europe 50 and STOXX Europe 600, STOXX Ltd. maintains and calculates the STOXX Global Index family which consists of total market, broad and blue-chip indices for the regions. Americas, Europe, Asia, and Pacific, the sub-regions Latin America and BRIC (Brazil, Russia, India and China), as well as global markets.

The STOXX indices are licensed to over 400 companies around the world as underlyings for Exchange Traded Funds (ETFs), Futures & Options, Structured Products and passively-managed investment funds. Three of the top Exchange Traded Funds (ETFs) in Europe and 30 percent of all assets under management are based on STOXX indices. STOXX Ltd. holds Europe’s number one and the world’s number three position in the derivatives segment.

In addition, STOXX Ltd. is the marketing agent for the indices of Deutsche Boerse Group, amongst them the DAX Index.

STOXX Ltd. is part of Deutsche Boerse Group.

Morningstar, Markit and STOXX Ltd. are not affiliated with the Trust or the Investment Adviser. The Investment Adviser has entered into a license agreement with each of Morningstar, Markit and STOXX Ltd. pursuant to which the Investment Adviser pays a fee to use the applicable Underlying Indexes. The Investment Adviser has entered into a sub-license agreement with the Trust for the use of the applicable Underlying Indexes at no charge.

* * *

ICE Data Indices, LLC is not affiliated with FlexShares® Trust or NTI. NTI has entered into a license agreement

with ICE Data Indices, LLC for the license to use the Underlying Index in connection with the FlexShares® Disciplined Duration MBS Index Fund. NTI has entered into a sub-license agreement with the FlexShares® Trust for use of the Underlying Index at no charge.

* * *

274

Disclaimers

NTI does not guarantee, and has no obligation to inquire into, the accuracy and/or the completeness of the Underlying Indexes or any data included therein or the descriptions of the Index Providers, and NTI shall have no liability for any errors, omissions, restatements, recalculations or interruptions therein.

NTI makes no warranty, express or implied, as to results to be obtained by the FlexShares® Funds, to the owners of the shares of any FlexShares® Fund, or to any other person or entity, from the use of any Underlying Index or any data included therein. NTI makes no express or implied warranties, and expressly disclaims all warranties of merchantability or fitness for a particular purpose or use with respect to any Underlying Index or any data included therein. Without limiting any of the foregoing, in no event shall NTI have any liability for any special, punitive, direct, indirect, or consequential damages (including lost profits regarding any Underlying Index or any data included therein), even if notified of the possibility of such damages.

* * *

Acting in the role of index provider to FlexShares® Trust, Morningstar licenses the Underlying Indexes and accompanying service marks to FlexShares® for FlexShares®’ further use in creating and maintaining the FlexShares® Morningstar US Market Factor Tilt Index Fund, the FlexShares® Morningstar Developed Markets ex-US Factor Tilt Index Fund, the FlexShares® Morningstar Emerging Markets Factor Tilt Index Fund, and the FlexShares® Morningstar Global Upstream Natural Resources Index Fund (collectively, the “Funds”). The Funds are not sponsored, endorsed, sold or promoted by Morningstar. Morningstar makes no representation or warranty, express or implied, to the owners of the Funds or any member of the public regarding the advisability of investing in securities generally or in the Funds in particular or the ability of the Underlying Indexes to track general stock market performance. Morningstar’s only relationship to NTI, FlexShares® Trust and the Funds is the licensing of the certain service marks and the Underlying Indexes, each of which is determined, composed and calculated by Morningstar without regard to NTI, FlexShares® Trust or the Funds. Morningstar has no obligation to take the needs of NTI, FlexShares® Trust, the Funds or the owners of the Funds into consideration in determining, composing or calculating the Underlying Indexes. Morningstar is not responsible for and has not participated in the determination of the prices and amounts of the Funds or the timing of the issuance or sale of the Funds or in the determination or calculation of the equation by which any Fund is converted into cash. Morningstar has no obligation or liability in connection with the administration, marketing or trading of the Funds.

MORNINGSTAR DOES NOT GUARANTEE THE ACCURACY AND/OR THE COMPLETENESS OF THE UNDERLYING INDEXES OR ANY DATA INCLUDED THEREIN AND MORNINGSTAR SHALL HAVE NO

LIABILITY FOR ANY ERRORS, OMISSIONS, OR INTERRUPTIONS THEREIN. MORNINGSTAR MAKES NO WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY NTI, FLEXSHARES® TRUST, THE FUNDS OR OWNERS OR USERS OF THE FUNDS, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE UNDERLYING INDEXES OR ANY DATA INCLUDED THEREIN. MORNINGSTAR MAKES NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE UNDERLYING INDEXES OR ANY DATA INCLUDED THEREIN. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL MORNINGSTAR HAVE ANY LIABILITY FOR ANY SPECIAL, PUNITIVE, INDIRECT, OR CONSEQUENTIAL DAMAGES (INCLUDING LOST PROFITS), EVEN IF NOTIFIED OF THE POSSIBILITY OF SUCH DAMAGES.

* * *

The iBoxx Target Duration TIPS Indexes (each, an “Index” and, collectively, the “Indexes”) is a product of S&P Dow Jones Indices LLC or its affiliates (the “Index Provider” or “SPDJI”), and has been licensed for use by the FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund and the FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund, respectively (collectively, the “Funds”). S&P®, S&P 500®, US 500, The 500, iBoxx®, iTraxx® and CDX® are trademarks of S&P Global, Inc. or its affiliates (“S&P”); Dow Jones® is a registered trademark of Dow Jones Trademark Holdings LLC (“Dow Jones”). It is not possible to invest directly in an index. The Funds are not sponsored, endorsed, sold or promoted by SPDJI, Dow Jones, S&P, any of their respective affiliates (collectively, “S&P Dow Jones Indices”). S&P Dow Jones Indices makes no representation or warranty, express or implied, to the owners of the Funds or any member of the public regarding the advisability of investing in securities generally or in the Funds particularly or the ability of the Indexes to track general market performance. Past performance of an index is not an indication or guarantee of future results. S&P Dow Jones Indices’ only relationship to the Funds with respect to the Indexes is the licensing of the Index and certain trademarks, service marks and/or trade names of S&P Dow Jones Indices and/or its licensors. The Indexes are determined, composed and calculated by S&P Dow Jones Indices without regard to the Funds. S&P Dow Jones Indices has no obligation to take the needs of the Funds or the owners of the Funds into consideration in determining, composing or calculating the Indexes. S&P Dow Jones Indices have no obligation or liability in connection with the administration, marketing or trading of the Funds. There is no assurance that investment products based on the Indexes will accurately track index performance or provide positive investment returns. The Index Provider is not an investment adviser, commodity trading advisory, commodity pool operator, broker dealer, fiduciary, promoter” (as defined in the Investment

275

Disclaimers (cont.)

Company Act of 1940, as amended), “expert” as enumerated within 15 U.S.C. § 77k(a) or tax advisor. Inclusion of a security, commodity, crypto currency or other asset within an index is not a recommendation by the Index Provider to buy, sell, or hold such security, commodity, crypto currency or other asset, nor is it considered to be investment advice or commodity trading advice.

S&P DOW JONES INDICES DOES NOT GUARANTEE THE ADEQUACY, ACCURACY, TIMELINESS AND/OR THE COMPLETENESS OF THE UNDERLYING INDEXES OR ANY DATA RELATED THERETO OR ANY COMMUNICATION, INCLUDING BUT NOT LIMITED TO, ORAL OR WRITTEN COMMUNICATION (INCLUDING ELECTRONIC COMMUNICATIONS) WITH RESPECT THERETO. S&P DOW JONES INDICES SHALL NOT BE SUBJECT TO ANY DAMAGES OR LIABILITY FOR ANY ERRORS, OMISSIONS, OR DELAYS THEREIN. S&P DOW JONES INDICES MAKES NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES, OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE OR AS TO RESULTS TO BE OBTAINED BY THE FUNDS, OWNERS OF THE FUNDS, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDEXES OR WITH RESPECT TO ANY DATA RELATED THERETO. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT WHATSOEVER SHALL S&P DOW JONES INDICES BE LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES INCLUDING BUT NOT LIMITED TO, LOSS OF PROFITS, TRADING LOSSES, LOST TIME OR GOODWILL, EVEN IF THEY HAVE BEEN ADVISED OF THE POSSIBLITY OF SUCH DAMAGES, WHETHER IN CONTRACT, TORT, STRICT LIABILITY, OR OTHERWISE. S&P DOW JONES INDICES HAS NOT REVIEWED, PREPARED AND/OR CERTIFIED ANY PORTION OF, NOR DOES S&P DOW JONES INDICES HAVE ANY CONTROL OVER, THE LICENSEE PRODUCT REGISTRATION STATEMENT, PROSPECTUS OR OTHER OFFERING MATERIALS. THERE ARE NO THIRD-PARTY BENEFICIARIES OF ANY AGREEMENTS OR ARRANGEMENTS BETWEEN S&P DOW JONES INDICES AND THE FUNDS, OTHER THAN THE LICENSORS OF S&P DOW JONES INDICES

* * *

Northern Trust Investments, Inc. and the FlexShares® U.S. Quality Low Volatility Index Fund, FlexShares® Developed Markets ex-US Quality Low Volatility Index Fund, FlexShares® Emerging Markets Quality Low Volatility Index Fund, FlexShares® ESG & Climate US Large Cap Core Index Fund, FlexShares® ESG & Climate Developed Markets ex-US Core Index Fund, FlexShares® ESG & Climate Emerging Markets Core Index Fund, FlexShares® Quality Dividend Index Fund, FlexShares® Quality Dividend Defensive Index Fund, FlexShares® International Quality Dividend Index Fund, FlexShares® International Quality

Dividend Dynamic Index Fund, and FlexShares® International Quality Dividend Defensive Index Fund, FlexShares® US Quality Large Cap Index Fund, FlexShares® Global Quality Real Estate Index Fund, FlexShares® Real Assets Allocation Index Fund, FlexShares® Credit-Scored US Corporate Bond Index Fund, FlexShares® Credit-Scored US Long Corporate Bond Index Fund and FlexShares® High Yield Value-Scored Bond Index Fund and FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund (each, a “Fund”, together, the “Funds”) make no representation or warranty, express or implied, to the owners of the Funds or any member of the public regarding the advisability of investing in securities generally or in the Funds in particular or the ability of the Northern Trust 600 IndexSM, Northern Trust 1250 IndexSM, Northern Trust Quality Low Volatility IndexSM, Northern Trust Developed Markets ex-US Quality Low Volatility IndexSM, Northern Trust Emerging Markets Quality Low Volatility IndexSM, Northern Trust International Large Cap IndexSM, Northern Trust Quality Dividend IndexSM, Northern Trust Quality Dividend Defensive IndexSM, Northern Trust International Quality Dividend IndexSM, Northern Trust International Quality Dividend Dynamic IndexSM, Northern Trust International Quality Dividend Defensive IndexSM, Northern Trust Quality Large Cap IndexSM, the Northern Trust Global Quality Real Estate IndexSM, the Northern Trust Global Real Estate IndexSM, Northern Trust Real Assets Allocation IndexSM, Northern Trust Global IndexSM, Northern Trust US Corporate Bond Quality Value IndexSM, Northern Trust US Long Corporate Bond Quality Value IndexSM, Northern Trust US Investment Grade Corporate Bond IndexSM, Northern Trust US Investment Grade Long Corporate Bond IndexSM and Northern Trust High Yield Value-Scored US Corporate Bond IndexSM, Northern Trust High Yield US Corporate Bond IndexSM, Northern Trust US Corporate Bond IndexSM, Northern Trust ESG & Climate U.S. Large Cap Core IndexSM, Northern Trust ESG & Climate Developed Markets ex-US Core IndexSM, Northern Trust ESG & Climate Emerging Markets Core IndexSM and Northern Trust ESG & Climate Investment Grade U.S. Corporate Core IndexSM (together, the “Northern Trust Indexes”) to track general stock market performance. Northern Trust Investments, Inc. is the licensor of certain trademarks, service marks and service names of the Funds. Northern Trust Investments, Inc. has no obligation to take the needs of FlexShares® Trust, the Funds or the owners of the Funds into consideration in determining, composing or calculating the Northern Trust Indexes.

NEITHER THE FUNDS NOR NORTHERN TRUST INVESTMENTS, INC. GUARANTEE THE ACCURACY, COMPLETENESS OR PERFORMANCE OF ANY NORTHERN TRUST INDEX OR ANY DATA INCLUDED THEREIN AND SHALL HAVE NO LIABILITY IN CONNECTION WITH ANY NORTHERN TRUST INDEX OR NORTHERN TRUST INDEX CALCULATION. NORTHERN TRUST INVESTMENTS, INC. MAKES NO WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE

276

Disclaimers (cont.)

OBTAINED BY FLEXSHARES® TRUST, THE FUNDS OR OWNERS OR USERS OF THE FUNDS, OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE NORTHERN TRUST INDEXES OR ANY DATA INCLUDED THEREIN. NORTHERN TRUST INVESTMENTS, INC. MAKES NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE WITH RESPECT TO THE NORTHERN TRUST INDEXES OR ANY DATA INCLUDED THEREIN. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL NORTHERN TRUST INVESTMENTS, INC. HAVE ANY LIABILITY FOR ANY SPECIAL, PUNITIVE, INDIRECT, OR CONSEQUENTIAL DAMAGES (INCLUDING LOST PROFITS), EVEN IF NOTIFIED OF THE POSSIBILITY OF SUCH DAMAGES.

Northern Trust Quality Low Volatility IndexSM, Northern Trust Developed Markets ex-US Quality Low Volatility IndexSM, Northern Trust Emerging Markets Quality Low Volatility IndexSM, Northern Trust ESG & Climate U.S. Large Cap Core IndexSM, Northern Trust ESG & Climate Developed Markets ex-US Core IndexSM, Northern Trust ESG & Climate Emerging Markets Core IndexSM, Northern Trust US Corporate Bond Quality Value IndexSM, Northern Trust US Long Corporate Bond Quality Value IndexSM, Northern Trust US Investment-Grade Corporate Bond IndexSM, Northern Trust US Investment-Grade Long Corporate Bond IndexSM and Northern Trust High Yield Value-Scored US Corporate Bond IndexSM and Northern Trust ESG & Climate Investment Grade U.S. Corporate Core IndexSM are service marks of NTI and have been licensed for use by FlexShares® Trust. FlexShares® is a registered trademark of NTI.

* * *

STOXX Limited, Deutsche Börse Group and their licensors (the “Licensors”), research partners or data providers have no relationship to FlexShares® Trust other than the licensing of the STOXX® USA ESG Select KPIs Index, STOXX® Global ESG Select KPIs Index and STOXX® Global Broad Infrastructure Index and the related trademarks for use in connection with the FlexShares® STOXX® US ESG Select Index Fund, FlexShares® STOXX® Global ESG Select Index Fund and FlexShares® STOXX® Global Broad Infrastructure Index Fund (the “Funds”).

STOXX, Deutsche Börse Group and their Licensors, research partners or data providers do not:

•Sponsor, endorse, sell or promote the Funds.

•Recommend that any person invest in the Funds or any other securities.

•Have any responsibility or liability for or make any decisions about the timing, amount or pricing of the Funds.

•Have any responsibility or liability for the administration, management or marketing of the Funds.

•Consider the needs of the Funds or the owners of the Funds in determining, composing or calculating the STOXX® USA ESG Select KPIs Index, STOXX® Global ESG Select KPIs Index and STOXX® Global Broad Infrastructure Index or have any obligation to do so.

STOXX, Deutsche Börse Group and their Licensors, research partners or data providers give no warranty and exclude any liability (whether in negligence or otherwise), in connection with the Funds or their performance.

STOXX does not assume any contractual relationship with the purchasers of the Funds or any other third parties.

Specifically,

•STOXX, Deutsche Börse Group and their Licensors, research partners or data providers do not give any warranty, express or implied, and exclude any liability about:

•The results to be obtained by the Funds, the owner of the Funds or any other person in connection with the use of the Indexes and the data included in the STOXX® USA ESG Select KPIs Index, STOXX® Global ESG Select KPIs Index and STOXX® Global Broad Infrastructure Index;

•The accuracy, timeliness, and completeness of the STOXX® USA ESG Select KPIs Index, STOXX® Global ESG Select KPIs Index and STOXX® Global Broad Infrastructure Index and their data;

•The merchantability and the fitness for a particular purpose or use of the STOXX® USA ESG Select KPIs Index, STOXX® Global ESG Select KPIs Index and STOXX® Global Broad Infrastructure Index and their data;

•The performance of the Funds generally.

•STOXX Deutsche Börse Group and their Licensors, research partners or data providers give no warranty and exclude any liability, for any errors, omissions or interruptions in the STOXX® USA ESG Select KPIs Index, STOXX® Global ESG Select KPIs Index and STOXX® Global Broad Infrastructure Index or their data;

•Under no circumstances will STOXX, Deutsche Börse Group or their Licensors, research partners or data providers be liable (whether in negligence or otherwise) for any lost profits or indirect, punitive, special or consequential damages or losses, arising as a result of such errors, omissions or interruptions in the STOXX® USA ESG Select KPIs Index, STOXX® Global ESG Select KPIs Index and STOXX® Global Broad Infrastructure Index or its data or generally in relation to the Funds,

277

Disclaimers (cont.)

even in circumstances where STOXX, Deutsche Börse Group or their Licensors, research partners or data providers are aware that such loss or damage may occur.

The licensing agreement between NTI and STOXX is solely for their benefit and not for the benefit of the owners of the Funds or any other third parties.

* * *

Shares of the Trust are not sponsored, endorsed or promoted by Cboe BZX, Nasdaq and NYSE Arca (the “Exchanges”). The Exchanges make no representation or warranty, express or implied, to the owners of the shares of any FlexShares® Fund or any member of the public regarding the ability of any FlexShares® Fund to track the total return performance of any Underlying Index or the ability of any Underlying Index identified herein to track stock market performance. The Exchanges are not responsible for, nor has it participated in, the determination of the compilation or the calculation of any Underlying Indices, nor in the determination of the timing of, prices of, or quantities of the shares of any FlexShares® Fund to be issued, nor in the determination or calculation of the equation by which the shares are redeemable. The Exchanges have no obligation or liability to owners of the shares of any FlexShares® Fund in connection with the administration, marketing or trading of the shares of the Fund.

The Exchanges do not guarantee the accuracy and/or the completeness of any Underlying Index or any data included therein. The Exchanges make no warranty, express or implied, as to results to be obtained by the Trust on behalf of its FlexShares® Funds as licensee, licensee’s customers and counterparties, owners of the shares of the Trust, or any other person or entity from the use of any Underlying Index or any data included therein in connection with the rights licensed as described herein or for any other use. The Exchanges make no express or implied warranties, and hereby expressly disclaim all warranties of merchantability or fitness for a particular purpose with respect to any Underlying Index or any data included therein. Without limiting any of the foregoing, in no event shall the Exchanges have any liability for any direct, indirect, special, punitive, consequential or any other damages (including lost profits) even if notified of the possibility of such damages.

* * *

Northern Trust 600 IndexSM, Northern Trust 1250 IndexSM, Northern Trust International Large Cap IndexSM, Northern Trust Quality Dividend IndexSM, Northern Trust Quality Dividend Defensive IndexSM, Northern Trust International Quality Dividend IndexSM, Northern Trust International Quality Dividend Dynamic IndexSM, Northern Trust International Quality Dividend Defensive IndexSM, Northern Trust Quality Large Cap IndexSM and Northern Trust Global Quality Real Estate IndexSM, are service marks

of NTI and have been licensed for use by FlexShares® Trust. FlexShares® is a registered trademark of NTI.

* * *
The ICE BofA® Constrained Duration US Mortgage Backed Securities IndexSM are trademarks of ICE Data Indices, LLC or its affiliates (“ICE”) or are being used with permission and have been licensed, along with The ICE BofA® Constrained Duration US Mortgage Backed Securities IndexSM (“Index”) for use by NTI in connection with the FlexShares® Disciplined Duration MBS Index Fund (the “Fund”). Neither the Fund, NTI, nor the FlexShares® Trust are sponsored, endorsed, sold or promoted by ICE. ICE does not make any representation or warranty, express or implied, to the owners of the Fund or any member of the public regarding the Fund or the advisability of investing in the Fund, particularly the ability of the Index to track performance of any market or strategy. ICE’s only relationship to NTI (“Licensee”) is the licensing of certain trademarks and trade names and the Index or components thereof. The Index is determined, composed and calculated by ICE and ICE is the administrator of the Index. ICE has no obligation to take the needs of the Licensee or the holders of the Fund into consideration in determining, composing or calculating the Index. ICE is not responsible for and has not participated in the determination of the timing of, prices of, or quantities of the Fund to be issued or in the determination or calculation of the equation by which the Fund is to be priced, sold, purchased, or redeemed. ICE has no obligation or liability in connection with the administration, marketing, or trading of the Fund.

ICE AND ITS THIRD-PARTY SUPPLIERS DO NOT GUARANTEE THE ACCURACY AND/OR THE COMPLETENESS OF THE INDEX OR ANY DATA INCLUDED THEREIN AND ICE SHALL HAVE NO LIABILITY FOR ANY ERRORS, OMISSIONS, UNAVAILABILITY, OR INTERRUPTIONS THEREIN. ICE MAKES NO WARRANTY, EXPRESS OR IMPLIED, AS TO RESULTS TO BE OBTAINED BY LICENSEE, HOLDERS OF THE FUND OR ANY OTHER PERSON OR ENTITY FROM THE USE OF THE INDEX OR ANY DATA INCLUDED THEREIN. ICE AND ITS THIRD-PARTY SUPPLIERS MAKE NO EXPRESS OR IMPLIED WARRANTIES, AND EXPRESSLY DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE, WITH RESPECT TO THE INDEX OR ANY DATA INCLUDED THEREIN. WITHOUT LIMITING ANY OF THE FOREGOING, IN NO EVENT SHALL ICE AND ITS THIRD-PARTY SUPPLIERS HAVE ANY LIABILITY FOR ANY SPECIAL, PUNITIVE, INDIRECT, INCIDENTAL, CONSEQUENTIAL DAMAGES, OR LOST PROFITS, EVEN IF NOTIFIED OF THE POSSIBILITY OF SUCH DAMAGES.

BofA® is a licensed registered trademark of Bank of America Corporation in the United States and other countries.

278

Supplemental Information

I. Premium/Discount Information

Information about the differences between the daily market prices on secondary markets for shares of the Funds and the Funds’ net asset values for various time periods, as applicable, is available by visiting the Funds’ website at flexshares.com.

II. Total Return Information

Additional information about the total return of each Fund and its Underlying Index for various time periods, as applicable, is available by visiting the Funds’ website at flexshares.com.

279

For More Information

Annual/Semi-Annual Reports and Statement of Additional Information (“SAI”)

Additional information about the Funds’ investments is available in the Trust’s annual and semi-annual reports to shareholders. In the Trust’s annual report, you will find a discussion of market conditions and investment strategies that significantly affected the Funds’ performance during its last fiscal year.

Additional information about the Funds and their policies also is available in the Funds’ SAI. The SAI is incorporated by reference into this Prospectus (and is legally considered part of this Prospectus).

The Trust’s annual and semiannual reports and the SAI are available free on the Trust’s website at flexshares.com, and upon request by calling the Funds at 1-855-FLEXETF (1-855-353-9383) or by sending an email request to: [email protected]. The SAI and other information are available from a financial intermediary (such as a broker-dealer or bank) through which the Funds’ shares may be purchased or sold.

TO OBTAIN OTHER INFORMATION AND FOR SHAREHOLDER INQUIRIES:

By Telephone

Call 1-855-FLEXETF (1-855-353-9383)

By Mail

FlexShares® ETFs

c/o Foreside Fund Services, LLC

Three Canal Plaza, Suite 100

Portland, ME 04101

On the Internet

The Funds’ documents are available online and may be downloaded from:

•The SEC’s website at sec.gov (text-only)

•FlexShares® Trust’s website at flexshares.com

Other information about the Funds is available on the EDGAR Database on the SEC’s internet site at sec.gov. You may also obtain copies of this information, after paying a duplicating fee, by electronic request at the following e-mail address: [email protected].

811-22555

FS00012-0324

	One Year	Since Inception of Fund	Inception Date of Fund
Before Taxes	12.21%	3.61%	7/15/2019
After Taxes on Distributions	11.45%	3.08%	—
After Taxes on Distributions and Sale of Shares	7.97%	2.88%	—
MSCI World ex-US Index*	17.94%	6.17%	—
Northern Trust Developed Markets ex-US Quality Low Volatility IndexSM*	12.33%	3.82%	—

	One Year	Five Year	Ten Year
Before Taxes	24.65%	14.54%	10.34%
After Taxes on Distributions	24.12%	14.07%	9.88%
After Taxes on Distributions and Sale of Shares	14.80%	11.58%	8.39%
Morningstar® US Market Factor Tilt IndexSM*	24.90%	14.69%	10.50%

	One Year	Five Year	Ten Year
Before Taxes	17.56%	7.62%	4.01%
After Taxes on Distributions	16.53%	6.80%	3.30%
After Taxes on Distributions and Sale of Shares	10.96%	5.88%	3.06%
Morningstar® Developed Markets ex-US Factor Tilt IndexSM*	17.56%	7.64%	4.07%

	One Year	Five Year	Ten Year
Before Taxes	12.52%	4.57%	2.85%
After Taxes on Distributions	11.38%	3.77%	2.19%
After Taxes on Distributions and Sale of Shares	8.09%	3.55%	2.19%
Morningstar® Emerging Markets Factor Tilt IndexSM*	13.65%	5.51%	3.62%

	One Year	Five Year	Since Inception of Fund	Inception Date of Fund
Before Taxes	25.86%	13.54%	11.26%	9/23/2015
After Taxes on Distributions	25.45%	13.13%	10.83%	—
After Taxes on Distributions and Sale of Shares	15.56%	10.78%	9.12%	—
S&P 500 Index*	26.29%	15.71%	13.58%	—
Northern Trust Quality Large Cap IndexSM*	26.30%	13.90%	11.59%	—

Fund	Ticker	Stock Exchange
FlexShares® US Quality Low Volatility Index Fund	QLV	NYSE Arca, Inc.
FlexShares® Developed Markets ex-US Quality Low Volatility Index Fund	QLVD	NYSE Arca, Inc.
FlexShares® Emerging Markets Quality Low Volatility Index Fund	QLVE	NYSE Arca, Inc.
FlexShares® Morningstar US Market Factor Tilt Index Fund	TILT	Cboe BZX Exchange, Inc.
FlexShares® Morningstar Developed Markets ex-US Factor Tilt Index Fund	TLTD	NYSE Arca, Inc.
FlexShares® Morningstar Emerging Markets Factor Tilt Index Fund	TLTE	NYSE Arca, Inc.
FlexShares® US Quality Large Cap Index Fund	QLC	Cboe BZX Exchange, Inc.
FlexShares® STOXX® US ESG Select Index Fund	ESG	Cboe BZX Exchange, Inc.
FlexShares® STOXX® Global ESG Select Index Fund	ESGG	Cboe BZX Exchange, Inc.
FlexShares® ESG & Climate US Large Cap Core Index Fund	FEUS	NYSE Arca, Inc.
FlexShares® ESG & Climate Developed Markets ex-US Core Index Fund	FEDM	NYSE Arca, Inc.
FlexShares® ESG & Climate Emerging Markets Core Index Fund	FEEM	NYSE Arca, Inc.
FlexShares® Morningstar Global Upstream Natural Resources Index Fund	GUNR	NYSE Arca, Inc.
FlexShares® STOXX® Global Broad Infrastructure Index Fund	NFRA	NYSE Arca, Inc.
FlexShares® Global Quality Real Estate Index Fund	GQRE	NYSE Arca, Inc.
FlexShares® Real Assets Allocation Index Fund	ASET	The Nasdaq Stock Market LLC
FlexShares® Quality Dividend Index Fund	QDF	NYSE Arca, Inc.
FlexShares® Quality Dividend Defensive Index Fund	QDEF	NYSE Arca, Inc.
FlexShares® International Quality Dividend Index Fund	IQDF	NYSE Arca, Inc.
FlexShares® International Quality Dividend Defensive Index Fund	IQDE	NYSE Arca, Inc.
FlexShares® International Quality Dividend Dynamic Index Fund	IQDY	NYSE Arca, Inc.
FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund	TDTT	NYSE Arca, Inc.
FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund	TDTF	NYSE Arca, Inc.
FlexShares® Disciplined Duration MBS Index Fund	MBSD	NYSE Arca, Inc.
FlexShares® Credit-Scored US Corporate Bond Index Fund	SKOR	The Nasdaq Stock Market LLC
FlexShares® Credit-Scored US Long Corporate Bond Index Fund	LKOR	Cboe BZX Exchange, Inc.
FlexShares® High Yield Value-Scored Bond Index Fund	HYGV	NYSE Arca, Inc.
FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund	FEIG	NYSE Arca, Inc.

Fund Summaries	2
FlexShares® US Quality Low Volatility Index Fund	2
FlexShares® Developed Markets ex-US Quality Low Volatility Index Fund	8
FlexShares® Emerging Markets Quality Low Volatility Index Fund	14
FlexShares® Morningstar US Market Factor Tilt Index Fund	21
FlexShares® Morningstar Developed Markets ex-US Factor Tilt Index Fund	26
FlexShares® Morningstar Emerging Markets Factor Tilt Index Fund	32
FlexShares® US Quality Large Cap Index Fund	39
FlexShares® STOXX® US ESG Select Index Fund	45
FlexShares® STOXX® Global ESG Select Index Fund	51
FlexShares® ESG & Climate US Large Cap Core Index Fund	58
FlexShares® ESG & Climate Developed Markets ex-US Core Index Fund	65
FlexShares® ESG & Climate Emerging Markets Core Index Fund	73
FlexShares® Morningstar Global Upstream Natural Resources Index Fund	82
FlexShares® STOXX® Global Broad Infrastructure Index Fund	89
FlexShares® Global Quality Real Estate Index Fund	97
FlexShares® Real Assets Allocation Index Fund	105
FlexShares® Quality Dividend Index Fund	113
FlexShares® Quality Dividend Defensive Index Fund	119
FlexShares® International Quality Dividend Index Fund	125
FlexShares® International Quality Dividend Defensive Index Fund	132
FlexShares® International Quality Dividend Dynamic Index Fund	139
FlexShares® iBoxx 3-Year Target Duration TIPS Index Fund	146
FlexShares® iBoxx 5-Year Target Duration TIPS Index Fund	151
FlexShares® Disciplined Duration MBS Index Fund	156
FlexShares® Credit-Scored US Corporate Bond Index Fund	163
FlexShares® Credit-Scored US Long Corporate Bond Index Fund	170
FlexShares® High Yield Value-Scored Bond Index Fund	177
FlexShares® ESG & Climate Investment Grade Corporate Core Index Fund	184
Broad-Based Securities Market Indices	192
Additional Fund Information	193
Additional Information About the Funds’ Principal Risks	195
Additional Information About the Funds’ Investments and Other Risks	226
Portfolio Holdings Information	231

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)	0.17%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.18%
Expense Reimbursement(2)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.17%

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Management Fees(1)	0.57%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.01%
Total Annual Fund Operating Expenses	0.58%
Expense Reimbursement(2)	-0.01%
Total Annual Fund Operating Expenses After Expense Reimbursement	0.57%

1 Year	$17
3 Years	$57
5 Years	$100
10 Years	$229

1 Year	$33
3 Years	$105
5 Years	$184
10 Years	$417

1 Year	$26
3 Years	$83
5 Years	$145
10 Years	$330

1 Year	$40
3 Years	$128
5 Years	$223
10 Years	$504