BLACKROCK INDEX FUNDS, INC.

Fund Overview

Key Facts About iShares Russell 2000 Small-Cap Index Fund

Investment Objective

The investment objective of iShares Russell 2000 Small-Cap Index Fund (“Russell 2000 Small-Cap Index Fund”or the “Fund”), a series of BlackRock Index Funds, Inc. (the “Corporation”), is to match the performance of the Russell 2000® Index (the “Russell 2000” or the “Underlying Index”) as closely as possible before the deduction of Fund expenses.

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 Russell 2000 Small-Cap Index Fund. You may pay other fees, such as brokerage commissions and other fees to your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock Advisors, LLC (“BlackRock”) and its affiliates) (each, a “Financial Intermediary”), which are not reflected in the table and example below.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)		Investor A Shares		Institutional Shares
Management Fee1,2		0.01%		0.01%
Distribution and/or Service (12b-1) Fees		0.25%		None
Other Expenses		0.16%		0.12%
Administration Fees	0.04%		0.04%
Miscellaneous Other Expenses	0.12%		0.08%
Total Annual Fund Operating Expenses		0.42%		0.13%
Fee Waivers and/or Expense Reimbursements2,3		(0.05)%		(0.01)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements2,3		0.37%		0.12%

The fees and expenses shown in the table and the example that follows include both the expenses of Russell 2000 Small-Cap Index Fund and Russell 2000 Small-Cap Index Fund’s share of the allocated expenses of Master Small Cap Index Series (the “Series”), a series of Quantitative Master Series LLC (the “Master LLC”). Management fees are paid by the Series.

As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 42, BlackRock has contractually agreed to waive the management fee with respect to any portion of the Series’ assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds managed by BlackRock or its affiliates that have a contractual management fee, through June 30, 2025. In addition, BlackRock has contractually agreed to waive its management fees by the amount of investment advisory fees the Series pays to BlackRock indirectly through its investment in money market funds managed by BlackRock or its affiliates, through June 30, 2025. The contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Master LLC or by a vote of a majority of the outstanding voting securities of the Series.

As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 42, BlackRock has contractually agreed to waive and/or reimburse fees and/or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements of Russell 2000 Small-Cap Index Fund (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) as a percentage of average daily net assets to 0.37% (for Investor A Shares) and 0.12% (for Institutional Shares) through June 30, 2025. In addition to the contractual waiver with respect to the Fund, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements of the Series (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Series expenses) to 0.07% of average daily net assets through June 30, 2025. These contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Corporation or of the Master LLC, as applicable, or by a vote of a majority of the outstanding voting securities of the Fund or the Series, as applicable.

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem 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. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Investor A Shares	$38	$130	$230	$525
Institutional Shares	$12	$41	$72	$165

Portfolio Turnover:

The Series 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 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. During the most recent fiscal year, the Series’ portfolio turnover rate was 29% of the average value of its portfolio.

Principal Investment Strategies of the Fund

Russell 2000 Small-Cap Index Fund employs a “passive” management approach, attempting to invest in a portfolio of assets whose performance is expected to match approximately the performance of the Russell 2000. The Fund will be substantially invested in securities in the Russell 2000, and will invest, under normal circumstances, at least 80% of its assets in securities or other financial instruments that are components of or have economic characteristics similar to the securities included in the Russell 2000. The Fund may change its target index if Fund management believes a different index would better enable the Fund to match the performance of the market segment represented by the current index.

The Fund may invest in a statistically selected sample of stocks included in the Russell 2000 and in derivative instruments linked to the Russell 2000. The Fund may not invest in all of the common stocks in the Russell 2000, or in the same weightings as in the Russell 2000. The Fund chooses investments so that the market capitalizations, industry weightings and other fundamental characteristics of the stocks and derivative instruments chosen are similar to the Russell 2000 as a whole. As of March 31, 2024, the companies in the Russell 2000 have a market capitalization ranging from $11 million to $58 billion.

The Fund is a “feeder” fund that invests all of its assets in the Series, a series of the Master LLC, which has the same investment objective and strategies as the Fund. All investments are made at the Series level. This structure is sometimes called a “master/feeder” structure. The Fund’s investment results will correspond directly to the investment results of the Series. For simplicity, this prospectus uses the name of the Fund or the term “Fund” (as applicable) to include the Series.

Principal Risks of Investing in the Fund

Risk is inherent in all investing. The value of your investment in Russell 2000 Small-Cap Index Fund, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of the principal risks of investing in the Fund. The relative significance of each risk factor below may change over time and you should review each risk factor carefully.

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Small Cap Securities Risk — Small cap companies may have limited product lines or markets. They may be less financially secure than larger, more established companies. They may depend on a more limited management group than larger capitalized companies.

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Index-Related Risk — There is no guarantee that the Fund’s investment results will have a high degree of correlation to those of the Underlying Index or that the Fund will achieve its investment objective. Market disruptions or high volatility, other unusual market circumstances and regulatory restrictions could have an adverse effect on the Fund’s ability to adjust its exposure to the required levels in order to track the Underlying Index. Errors in index data, index computations or the construction of the Underlying Index in accordance with its methodology may occur from time to time and may not be identified and corrected by the index provider for a period of time or at all, which may have an adverse impact on the Fund and its shareholders. Unusual market conditions or other unforeseen circumstances (such as natural disasters, political unrest or war) may impact the index provider or a third-party data provider and could cause the index provider to postpone a scheduled rebalance. This could cause the Underlying Index to vary from its normal or expected composition.

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Passive Investment Risk — Because BlackRock does not select individual companies in the index that the Fund tracks, the Fund may hold securities of companies that present risks that an investment adviser researching individual securities might seek to avoid.

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Tracking Error Risk — The Fund may be subject to tracking error, which is the divergence of the Fund’s performance from that of the Underlying Index. Tracking error may occur because of differences between the securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund’s valuation of a security at the time of calculation of the Fund’s net asset value), differences in transaction costs, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of dividends or other distributions, interest, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index and the cost to the Fund of complying with various new or existing regulatory requirements. These risks may be heightened during times of increased market volatility or other unusual market conditions. In addition, tracking error may result because the Fund incurs fees and expenses, while the Underlying Index does not.

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Equity Securities Risk — Stock markets are volatile. The price of equity securities fluctuates based on changes in a company’s financial condition and overall market and economic conditions.

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Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.

An outbreak of an infectious coronavirus (COVID-19) that was first detected in December 2019 developed into a global pandemic that has resulted in numerous disruptions in the market and has had significant economic impact leaving general concern and uncertainty. Although vaccines have been developed and approved for use by various governments, the duration of the pandemic and its effects cannot be predicted with certainty. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time.

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Representative Sampling Risk — Representative sampling is a method of indexing that involves investing in a representative sample of securities that collectively have a similar investment profile to the Underlying Index and resemble the Underlying Index in terms of risk factors and other key characteristics. The Fund may or may not hold every security in the Underlying Index. When the Fund deviates from a full replication indexing strategy to utilize a representative sampling strategy, the Fund is subject to an increased risk of tracking error, in that the securities selected in the aggregate for the Fund may not have an investment profile similar to those of the Underlying Index.

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Risk of Investing in the United States — Certain changes in the U.S. economy, such as when the U.S. economy weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has exposure.

Performance Information

The information shows how the Fund’s performance has varied year by year and provides some indication of the risks of investing in the Fund. The table compares the Fund’s performance to that of the Russell 2000. To the extent that dividends and distributions have been paid by the Fund, the performance information for the Fund in the chart and table assumes reinvestment of the dividends and distributions. As with all such investments, past performance (before and after taxes) is not an indication of future results. The table includes all applicable fees. If BlackRock and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund’s returns would have been lower. Updated information on the Fund’s performance, including its current net asset value, can be obtained by visiting www.blackrock.com or can be obtained by phone at (800) 882-0052.

Investor A Shares
ANNUAL TOTAL RETURNS
Russell 2000 Small-Cap Index Fund
As of 12/31

During the ten-year period shown in the bar chart, the highest return for a quarter was 31.27% (quarter ended December 31, 2020) and the lowest return for a quarter was -30.60% (quarter ended March 31, 2020).

For the periods ended 12/31/23 Average Annual Total Returns	1 Year	5 Years	10 Years
iShares Russell 2000 Small-Cap Index Fund — Investor A Shares
Return Before Taxes	16.60 %	9.68 %	6.88 %
Return After Taxes on Distributions	15.79 %	8.77 %	5.77 %
Return After Taxes on Distributions and Sale of Fund Shares	10.26 %	7.53 %	5.23 %
iShares Russell 2000 Small-Cap Index Fund — Institutional Shares
Return Before Taxes	16.90 %	9.96 %	7.14 %
Russell 2000® Index (Reflects no deduction for fees, expenses or taxes)	16.93 %	9.97 %	7.16 %

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 the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns are shown for Investor A Shares only, and the after-tax returns for Institutional Shares will vary.

Investment Manager

Russell 2000 Small-Cap Index Fund’s investment manager is BlackRock Advisors, LLC (previously defined as “BlackRock”). Russell 2000 Small-Cap Index Fund’s sub-adviser is BlackRock Fund Advisors (the “Sub-Adviser”). Where applicable, “BlackRock” refers also to the Sub-Adviser.

Portfolio Managers

Portfolio Manager	Portfolio Manager of the Series Since	Title
Paul Whitehead	2022	Managing Director of BlackRock, Inc.
Jennifer Hsui, CFA	2016	Managing Director of BlackRock, Inc.

Purchase and Sale of Fund Shares

You may purchase or redeem shares of the Fund each day the New York Stock Exchange is open. To purchase or sell shares you should contact your Financial Intermediary, or, if you hold your shares through the Fund, you should contact the Fund by phone at (800) 441-7762, by mail (c/o BlackRock Funds, P.O. Box 534429, Pittsburgh, Pennsylvania 15253-4429), or by the Internet at www.blackrock.com. The Fund’s initial and subsequent investment minimums generally are as follows, although the Fund may reduce or waive the minimums in some cases:

	Investor A Shares	Institutional Shares
Minimum Initial Investment	$1,000 for all accounts except: •$50, if establishing an Automatic Investment Plan. •There is no investment minimum for employer- sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs). •There is no investment minimum for certain fee- based programs.	There is no minimum initial investment for: •Employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs), state sponsored 529 college savings plans, collective trust funds, investment companies or other pooled investment vehicles, unaffiliated thrifts and unaffiliated banks and trust companies, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to purchase such shares. •Clients of Financial Intermediaries that: (i) charge such clients a fee for advisory, investment consulting, or similar services or (ii) have entered into an agreement with the Fund’s distributor to offer Institutional Shares through a no-load program or investment platform. •Clients investing through a self-directed IRA brokerage account program sponsored by a retirement plan record-keeper, provided that such program offers only mutual fund options and that the program maintains an account with the Fund on an omnibus basis. $2 million for individuals and “Institutional Investors,” which include, but are not limited to, endowments, foundations, family offices, local, city, and state governmental institutions, corporations and insurance company separate accounts who may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to purchase such shares. $1,000 for: •Clients investing through Financial Intermediaries that offer such shares on a platform that charges a transaction based sales commission outside of the Fund. •Tax-qualified accounts for insurance agents that are registered representatives of an insurance company’s broker-dealer that has entered into an agreement with the Fund’s distributor to offer Institutional Shares, and the family members of such persons.
Minimum Additional Investment	$50 for all accounts (with the exception of certain employer-sponsored retirement plans which may have a lower minimum).	No subsequent minimum.

Tax Information

The Fund’s dividends and distributions may be subject to U.S. federal income taxes and may be taxed as ordinary income or capital gains, unless you are a tax-exempt investor or are investing through a qualified tax-exempt plan described in section 401(a) of the Internal Revenue Code of 1986, as amended, in which case you may be subject to U.S. federal income tax when distributions are received from such tax-deferred arrangements.

Payments to Broker/Dealers and Other Financial Intermediaries

If you purchase shares of the Fund through a Financial Intermediary, the Fund and BlackRock Investments, LLC, the Fund’s distributor, or its affiliates may pay the Financial Intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the Financial Intermediary and your individual financial professional to recommend the Fund over another investment.

Fund Overview

Key Facts About iShares MSCI EAFE International Index Fund

Investment Objective

The investment objective of iShares MSCI EAFE International Index Fund (“MSCI EAFE International Index Fund”or the “Fund”), a series of BlackRock Index Funds, Inc. (the “Corporation”), is to match the performance of the MSCI EAFE Index (Europe, Australasia, Far East) (the “MSCI EAFE Index” or the “Underlying Index”) in U.S. dollars with net dividends as closely as possible before the deduction of Fund expenses.

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 MSCI EAFE International Index Fund. You may pay other fees, such as brokerage commissions and other fees to your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock Advisors, LLC (“BlackRock”) and its affiliates) (each, a “Financial Intermediary”), which are not reflected in the table and example below.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)		Investor A Shares		Institutional Shares
Management Fee1		0.01%		0.01%
Distribution and/or Service (12b-1) Fees		0.25%		None
Other Expenses2		0.09%		0.09%
Administration Fees	0.08%		0.08%
Independent Expenses2	—		—
Miscellaneous Other Expenses	0.01%		0.01%
Total Annual Fund Operating Expenses		0.35%		0.10%
Fee Waivers and/or Expense Reimbursements1,2		—		—
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements1,2		0.35%		0.10%

As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 42, BlackRock has contractually agreed to waive the management fee with respect to any portion of the Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds managed by BlackRock or its affiliates that have a contractual management fee, through June 30, 2025. In addition, BlackRock has contractually agreed to waive its management fees by the amount of investment advisory fees the Fund pays to BlackRock indirectly through its investment in money market funds managed by BlackRock or its affiliates, through June 30, 2025. The contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Corporation or by a vote of a majority of the outstanding voting securities of the Fund.

Independent Expenses consist of the Fund’s allocable portion of the fees and expenses of the independent directors of the Corporation, counsel to such independent directors and the independent registered public accounting firm that provides audit services to the Fund. BlackRock has contractually agreed to reimburse, or provide offsetting credits to, the Fund for Independent Expenses through June 30, 2034. After giving effect to such contractual arrangements, Independent Expenses will be 0.00%. Such contractual arrangements may not be terminated prior to July 1, 2034 without the consent of the Board of Directors of the Corporation.

Example:

	1 Year	3 Years	5 Years	10 Years
Investor A Shares	$36	$113	$197	$443
Institutional Shares	$10	$32	$56	$128

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 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. During the most recent fiscal year, the Fund’s portfolio turnover rate was 17% of the average value of its portfolio.

Principal Investment Strategies of the Fund

MSCI EAFE International Index Fund employs a “passive” management approach, attempting to invest in a portfolio of assets whose performance is expected to match approximately the performance of the MSCI EAFE Index. The Fund will be substantially invested in securities in the MSCI EAFE Index, and will invest, under normal circumstances, at least 80% of its assets in securities or other financial instruments that are components of or have economic characteristics similar to the securities included in the MSCI EAFE Index. The Fund may change its target index if Fund management believes a different index would better enable the Fund to match the performance of the market segment represented by the current index.

MSCI EAFE International Index Fund invests in a statistically selected sample of equity securities included in the MSCI EAFE Index and in derivative instruments linked to the MSCI EAFE Index. Equity securities include common stock, preferred stock and securities or other instruments whose price is linked to the value of common stock. The Fund will, under normal circumstances, invest in all of the countries represented in the MSCI EAFE Index. The Fund may not, however, invest in all of the companies within a country represented in the MSCI EAFE Index, or in the same weightings as in the MSCI EAFE Index.

Principal Risks of Investing in the Fund

Risk is inherent in all investing. The value of your investment in MSCI EAFE International Index Fund, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of the principal risks of investing in the Fund. The relative significance of each risk factor below may change over time and you should review each risk factor carefully.

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Equity Securities Risk — Stock markets are volatile. The price of equity securities fluctuates based on changes in a company’s financial condition and overall market and economic conditions.

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Foreign Securities Risk — Foreign investments often involve special risks not present in U.S. investments that can increase the chances that the Fund will lose money. These risks include:

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The Fund generally holds its foreign securities and cash in foreign banks and securities depositories, which may be recently organized or new to the foreign custody business and may be subject to only limited or no regulatory oversight.

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Changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.

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The economies of certain foreign markets may not compare favorably with the economy of the United States with respect to such issues as growth of gross national product, reinvestment of capital, resources and balance of payments position.

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The governments of certain countries, or the U.S. Government with respect to certain countries, may prohibit or impose substantial restrictions through capital controls and/or sanctions on foreign investments in the capital markets or certain industries in those countries, which may prohibit or restrict the ability to own or transfer currency, securities, derivatives or other assets.

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Many foreign governments do not supervise and regulate stock exchanges, brokers and the sale of securities to the same extent as does the United States and may not have laws to protect investors that are comparable to U.S. securities laws.

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Settlement and clearance procedures in certain foreign markets may result in delays in payment for or delivery of securities not typically associated with settlement and clearance of U.S. investments.

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The Fund’s claims to recover foreign withholding taxes may not be successful, and if the likelihood of recovery of foreign withholding taxes materially decreases, due to, for example, a change in tax regulation or approach in the foreign country, accruals in the Fund’s net asset value for such refunds may be written down partially or in full, which will adversely affect the Fund’s net asset value.

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The European financial markets have recently experienced volatility and adverse trends due to concerns about economic downturns in, or rising government debt levels of, several European countries as well as acts of war in the region. These events may spread to other countries in Europe and may affect the value and liquidity of certain of the Fund’s investments.

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Performance Information

The information shows how the Fund’s performance has varied year by year and provides some indication of the risks of investing in the Fund. The table compares the Fund’s performance to that of the MSCI EAFE Index. To the extent that dividends and distributions have been paid by the Fund, the performance information for the Fund in the chart and table assumes reinvestment of the dividends and distributions. As with all such investments, past performance (before and after taxes) is not an indication of future results. The table includes all applicable fees. If BlackRock and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund’s returns would have been lower. Updated information on the Fund’s performance, including its current net asset value, can be obtained by visiting www.blackrock.com or can be obtained by phone at (800) 882-0052.

Investor A Shares
ANNUAL TOTAL RETURNS
MSCI EAFE International Index Fund
As of 12/31

During the ten-year period shown in the bar chart, the highest return for a quarter was 18.07% (quarter ended December 31, 2022) and the lowest return for a quarter was -23.37% (quarter ended March 31, 2020).

For the periods ended 12/31/23 Average Annual Total Returns	1 Year	5 Years	10 Years
iShares MSCI EAFE International Index Fund — Investor A Shares
Return Before Taxes	18.02 %	7.98 %	3.97 %
Return After Taxes on Distributions	17.32 %	7.47 %	3.53 %
Return After Taxes on Distributions and Sale of Fund Shares	11.35 %	6.39 %	3.20 %
iShares MSCI EAFE International Index Fund — Institutional Shares
Return Before Taxes	18.33 %	8.25 %	4.24 %
MSCI EAFE Index (Europe, Australasia, Far East) (Reflects no deduction for fees, expenses or taxes)	18.24 %	8.16 %	4.28 %

Investment Manager

MSCI EAFE International Index Fund’s investment manager is BlackRock Advisors, LLC (previously defined as “BlackRock”). MSCI EAFE International Index Fund’s sub-adviser is BlackRock Fund Advisors (the “Sub-Adviser”). Where applicable, “BlackRock” refers also to the Sub-Adviser.

Portfolio Managers

Portfolio Manager	Portfolio Manager of the Fund Since	Title
Paul Whitehead	2022	Managing Director of BlackRock, Inc.
Jennifer Hsui, CFA	2016	Managing Director of BlackRock, Inc.

Purchase and Sale of Fund Shares

	Investor A Shares	Institutional Shares
Minimum Initial Investment	$1,000 for all accounts except: •$50, if establishing an Automatic Investment Plan. •There is no investment minimum for employer- sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs). •There is no investment minimum for certain fee- based programs.	There is no minimum initial investment for: •Employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs), state sponsored 529 college savings plans, collective trust funds, investment companies or other pooled investment vehicles, unaffiliated thrifts and unaffiliated banks and trust companies, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to purchase such shares. •Clients of Financial Intermediaries that: (i) charge such clients a fee for advisory, investment consulting, or similar services or (ii) have entered into an agreement with the Fund’s distributor to offer Institutional Shares through a no-load program or investment platform. •Clients investing through a self-directed IRA brokerage account program sponsored by a retirement plan record-keeper, provided that such program offers only mutual fund options and that the program maintains an account with the Fund on an omnibus basis. $2 million for individuals and “Institutional Investors,” which include, but are not limited to, endowments, foundations, family offices, local, city, and state governmental institutions, corporations and insurance company separate accounts who may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to purchase such shares. $1,000 for: •Clients investing through Financial Intermediaries that offer such shares on a platform that charges a transaction based sales commission outside of the Fund. •Tax-qualified accounts for insurance agents that are registered representatives of an insurance company’s broker-dealer that has entered into an agreement with the Fund’s distributor to offer Institutional Shares, and the family members of such persons.
Minimum Additional Investment	$50 for all accounts (with the exception of certain employer-sponsored retirement plans which may have a lower minimum).	No subsequent minimum.

Tax Information

Payments to Broker/Dealers and Other Financial Intermediaries

Details About the Funds

Included in this prospectus are sections that tell you about buying and selling shares, management information, shareholder features of iShares Russell 2000 Small-Cap Index Fund (“Russell 2000 Small-Cap Index Fund”) and iShares MSCI EAFE International Index Fund (“MSCI EAFE International Index Fund”) (each a “Fund” and collectively the “Funds”), each a series of BlackRock Index Funds, Inc. (the “Corporation”), and your rights as a shareholder. Russell 2000 Small-Cap Index Fund is a “feeder” fund that invests all of its assets in Master Small Cap Index Series (the “Series”), a series of Quantitative Master Series LLC (the “Master LLC”), which has the same objective and strategies as Russell 2000 Small-Cap Index Fund. All of Russell 2000 Small-Cap Index Fund’s investments will be made at the Master LLC level. This structure is sometimes called a “master/feeder” structure. Russell 2000 Small-Cap Index Fund’s investment results will correspond directly to the investment results of the Series. For simplicity, this prospectus uses the name “Russell 2000 Small-Cap Index Fund” or the term “Fund,” if applicable, to include the Series.

How Each Fund Invests

Investment Process

The Funds will not attempt to buy or sell securities based on Fund management’s economic, financial or market analysis, but will instead employ a “passive” investment approach. This means that Fund management will attempt to invest in a portfolio of assets whose performance is expected to match approximately the performance of the respective index before deduction of Fund expenses. A Fund will buy or sell securities only when Fund management believes it is necessary to do so in order to match the performance of the applicable index. Accordingly, it is anticipated that a Fund’s portfolio turnover rate and trading costs will be lower than those of an “actively” managed fund. However, the Funds have operating and other expenses, while an index does not. Therefore, each Fund will tend to underperform its target index to some degree over time.

Russell 2000 Small-Cap Index Fund

Investment Objective

The investment objective of Russell 2000 Small-Cap Index Fund is to match the performance of the Russell 2000® Index (the “Russell 2000” or the “Underlying Index”) as closely as possible before the deduction of Fund expenses.

The Russell 2000 is composed of the common stocks of approximately the 1,001st through the 3,000th largest U.S. companies by market capitalization, as determined by Russell Investments (“Russell” or the “Index Provider”). The stocks represented in the Russell 2000 are issued by small capitalization U.S. companies in a wide range of businesses. The Russell 2000 is a market-weighted index, which means that the largest stocks represented in the index have the most effect on the index’s performance. The Russell 2000 is generally considered broadly representative of the performance of publicly traded U.S. smaller-capitalization stocks. Russell’s selection of a stock for the Russell 2000 does not mean that Russell believes the stock to be an attractive investment. Russell updates the Russell 2000 once each year, at which time there may be substantial changes in the composition of the index (and consequently, significant turnover in the Fund). Stocks of companies that merge, are acquired or otherwise cease to exist during the year are not replaced in the index.

Principal Investment Strategies

Russell 2000 Small-Cap Index Fund will be substantially invested in securities in the Russell 2000, and will invest, under normal circumstances, at least 80% of its assets in securities or other financial instruments that are components of or have economic characteristics similar to the securities included in the Russell 2000. This is a non-fundamental policy of the Fund and may not be changed without 60 days’ prior notice to shareholders. The Fund may change its target index if Fund management believes a different index would better enable the Fund to match the performance of the market segment represented by the Russell 2000 and, accordingly, the investment objective of the Fund may be changed without shareholder approval.

The Fund may not invest in all of the common stocks in the Russell 2000, or in the same weightings as in the Russell 2000. Instead, the Fund may invest in a statistically selected sample of the stocks included in the Russell 2000 and in derivative instruments linked to the Russell 2000. The Fund will choose investments so that the market capitalizations, industry weightings and other fundamental characteristics of the stocks and derivative instruments in

its portfolio are similar to the Russell 2000 as a whole. As of March 31, 2024, the companies in the Russell 2000 have a market capitalization ranging from $11 million to $58 billion.

The past performance of the Underlying Index is not a guide to future performance. BlackRock Advisors, LLC (“BlackRock”) does not guarantee the accuracy or the completeness of the Underlying Index or any data included therein and BlackRock shall have no liability for any errors, omissions or interruptions therein. BlackRock makes no warranty, express or implied, to the owners of shares of the Fund or to any other person or entity, as to results to be obtained by the Fund from the use of the Underlying Index or any data included therein. Without limiting any of the foregoing, in no event shall BlackRock have any liability for any special, punitive, direct, indirect or consequential damages (including lost profits), even if notified of the possibility of such damages.

ABOUT THE PORTFOLIO MANAGEMENT TEAM OF MASTER SMALL CAP INDEX SERIES

The Series is managed by a team of financial professionals. Paul Whitehead and Jennifer Hsui, CFA are the portfolio managers of the Series and are jointly and primarily responsible for the day-to-day management of the Series. Please see “Management of the Funds — Portfolio Manager Information” for additional information about the portfolio management team.

MSCI EAFE International Index Fund

Investment Objective

The investment objective of MSCI EAFE International Index Fund is to match the performance of the MSCI EAFE Index (Europe, Australasia, Far East) (the “MSCI EAFE Index” or the “Underlying Index”) in U.S. dollars with net dividends as closely as possible before the deduction of Fund expenses.

The MSCI EAFE Index is composed of equity securities of approximately 1,000 companies from various industrial sectors whose primary trading markets are located outside the United States. Equity securities include common stock, preferred stock and securities or other instruments whose price is linked to the value of common stock. Companies included in the MSCI EAFE Index are selected from among the larger capitalization companies in these markets. The countries currently included in the MSCI EAFE Index are Australia, Austria, Belgium, Denmark, Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, the Netherlands, New Zealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland and the United Kingdom. The weighting of the MSCI EAFE Index among these countries is based upon each country’s relative market capitalization and not its gross domestic product, which means that the index contains more companies from countries with larger capital markets (like Japan and the United Kingdom) and these countries have the most effect on the index’s performance. The stocks in the MSCI EAFE Index are chosen by MSCI Inc. (“MSCI” or the “Index Provider”). MSCI chooses stocks for inclusion in the MSCI EAFE Index based on market capitalization, trading activity and the overall mix of industries represented in the index, among other factors. The MSCI EAFE Index is generally considered broadly representative of the performance of stocks traded in the developed international markets. MSCI’s selection of a stock for the MSCI EAFE Index does not mean that MSCI believes the stock to be an attractive investment.

Principal Investment Strategies

MSCI EAFE International Index Fund will be substantially invested in securities in the MSCI EAFE Index, and will invest, under normal circumstances, at least 80% of its assets in securities or other financial instruments that are components of or have economic characteristics similar to the securities included in the MSCI EAFE Index. This is a non-fundamental policy of the Fund and may not be changed without 60 days’ prior notice to shareholders. The Fund may change its target index if Fund management believes a different index would better enable the Fund to match the performance of the market segment represented by the MSCI EAFE Index and, accordingly, the investment objective of the Fund may be changed without shareholder approval.

The Fund will, under normal circumstances, invest in all of the countries represented in the MSCI EAFE Index. The Fund may not, however, invest in all of the companies within a country represented in the MSCI EAFE Index, or in the same weightings as in the MSCI EAFE Index. Instead, the Fund may invest in a statistically selected sample of equity securities included in the MSCI EAFE Index and in derivative instruments correlated with components of the MSCI EAFE Index as a whole.

The past performance of the Underlying Index is not a guide to future performance. BlackRock does not guarantee the accuracy or the completeness of the Underlying Index or any data included therein and BlackRock shall have no liability for any errors, omissions or interruptions therein. BlackRock makes no warranty, express or implied, to the owners of shares of the Fund or to any other person or entity, as to results to be obtained by the Fund from the use of the

Underlying Index or any data included therein. Without limiting any of the foregoing, in no event shall BlackRock have any liability for any special, punitive, direct, indirect or consequential damages (including lost profits), even if notified of the possibility of such damages.

ABOUT THE PORTFOLIO MANAGEMENT TEAM OF MSCI EAFE INTERNATIONAL INDEX FUND

The Fund is managed by a team of financial professionals. Paul Whitehead and Jennifer Hsui, CFA are the portfolio managers of the Fund and are jointly and primarily responsible for the day-to-day management of the Fund. Please see “Management of the Funds — Portfolio Manager Information” for additional information about the portfolio management team.

Other Strategies Applicable to the Funds

In addition to the principal strategies discussed above, each Fund may also invest or engage in the following investments/strategies:

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Borrowing — Each Fund may borrow for temporary or emergency purposes, including to meet redemptions, for the payment of dividends, for share repurchases or for the clearance of transactions, subject to the limits set forth under the Investment Company Act of 1940, as amended (the “Investment Company Act”), the rules and regulations thereunder and any applicable exemptive relief.

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Depositary Receipts — Each Fund may invest in securities of foreign issuers in the form of depositary receipts or other securities that are convertible into securities of foreign issuers. American Depositary Receipts are receipts typically issued by an American bank or trust company that evidence underlying securities issued by a foreign corporation. European Depositary Receipts (issued in Europe) and Global Depositary Receipts (issued throughout the world) each evidence a similar ownership arrangement. Each Fund may invest in unsponsored depositary receipts.

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Derivatives — Each Fund may invest in derivative instruments. Russell 2000 Small-Cap Index Fund may at times invest a significant portion of its assets in futures contracts and other derivatives linked to the performance of the Russell 2000, and MSCI EAFE International Index Fund may at times invest a significant portion of its assets in futures contracts and other derivatives correlated with market indices or countries within the MSCI EAFE Index. Derivatives allow a Fund to increase or decrease its exposure to the companies included in the Russell 2000 (for Russell 2000 Small-Cap Index Fund) and to international stocks (for MSCI EAFE International Index Fund) quickly and at less cost than buying or selling stocks. The Funds will invest in futures and other derivative instruments in order to gain market exposure quickly in the event of subscriptions, to maintain liquidity in the event of redemptions and to keep trading costs low. In connection with the use of derivative instruments, the Funds may enter into short sales in order to adjust the weightings of particular securities represented in a derivative to more accurately reflect the securities’ weightings in the target index. The Funds may use derivatives for hedging purposes, including anticipatory hedges, and to seek to enhance returns.

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Illiquid Investments — Each Fund may invest up to an aggregate amount of 15% of its net assets in illiquid investments. An illiquid investment is any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment.

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Investment Companies — Each Fund has the ability to invest in other investment companies, such as exchange-traded funds (“ETFs”), unit investment trusts, and open-end and closed-end funds, subject to the applicable limits under the Investment Company Act and the rules thereunder. Each Fund may invest in affiliated investment companies, including affiliated money market funds and affiliated ETFs.

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“New Issues” (Russell 2000 Small-Cap Index Fund) — The Fund has the ability to invest in “new issues.” “New issues” are initial public offerings (“IPOs”) of equity securities.

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Real Estate Investment Trusts (“REITs”) — Each Fund may invest in REITs. REITs are companies that own interests in real estate or in real estate-related loans or other interests, and have revenue primarily consisting of rent derived from owned, income producing real estate properties and capital gains from the sale of such properties. REITs can generally be classified as equity REITs, mortgage REITs and hybrid REITs. Equity REITs invest the majority of their assets directly in real property and derive their income primarily from rents. Equity REITs can also realize capital gains by selling properties that have appreciated in value. Mortgage REITs invest the majority of their assets in real estate mortgages and derive their income primarily from interest payments. Hybrid REITs combine the characteristics of both equity REITs and mortgage REITs. REITs are not taxed on income distributed to

shareholders provided they comply with the requirements of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”).

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Repurchase Agreements — Each Fund may enter into certain types of repurchase agreements. Under a repurchase agreement, the seller agrees to repurchase a security at a mutually agreed-upon time and price.

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Restricted Securities — Restricted securities are securities that cannot be offered for public resale unless registered under the applicable securities laws or that have a contractual restriction that prohibits or limits their resale. They may include Rule 144A securities, which are privately placed securities that can be resold to qualified institutional buyers but not to the general public, and securities of U.S. and non-U.S. issuers that are offered pursuant to Regulation S under the Securities Act of 1933, as amended.

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Securities Lending — Each Fund may lend securities with a value up to 33 1∕3% of its total assets to financial institutions that provide cash or securities issued or guaranteed by the U.S. Government as collateral.

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Short-Term Money Market Instruments — Each Fund may invest in short-term money market instruments as cash reserves to maintain liquidity. These instruments may include obligations of the U.S. Government, its agencies or instrumentalities, highly rated bonds or comparable unrated bonds, commercial paper, bank obligations, repurchase agreements and commingled short-term liquidity funds. To the extent a Fund invests in short-term money market instruments, it will generally also invest in futures or other derivatives in order to maintain full exposure to the index at all times.

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When-Issued and Delayed Delivery Securities and Forward Commitments (Russell 2000 Small-Cap Index Fund) — The purchase or sale of securities on a when-issued basis or on a delayed delivery basis or through a forward commitment involves the purchase or sale of securities by the Fund at an established price with payment and delivery taking place in the future. The Fund enters into these transactions to obtain what is considered an advantageous price to the Fund at the time of entering into the transaction.

Investment Risks

This section contains a discussion of the general risks of investing in the Funds. The “Investment Objectives and Policies” section in the Statement of Additional Information (the “SAI”) also includes more information about the Funds, their investments and the related risks. As with any fund, there can be no guarantee that a Fund will meet its investment objective or that a Fund’s performance will be positive for any period of time. An investment in a Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or by any bank or governmental agency. The order of the below risk factors does not indicate the significance of any particular risk factor.

Principal Risks of Investing in the Funds

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Equity Securities Risk — Common and preferred stocks represent equity ownership in a company. Stock markets are volatile. The price of equity securities will fluctuate and can decline and reduce the value of a portfolio investing in equities. The value of equity securities purchased by the Fund could decline if the financial condition of the companies the Fund invests in declines or if overall market and economic conditions deteriorate. The value of equity securities may also decline due to factors that affect a particular industry or industries, such as labor shortages or an increase in production costs and competitive conditions within an industry. In addition, the value may decline due to general market conditions that are not specifically related to a company or industry, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in inflation, interest or currency rates or generally adverse investor sentiment.

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Foreign Securities Risk (MSCI EAFE International Index Fund) — Securities traded in foreign markets have often (though not always) performed differently from securities traded in the United States. However, such investments often involve special risks not present in U.S. investments that can increase the chances that the Fund will lose money. In particular, the Fund is subject to the risk that because there may be fewer investors on foreign exchanges and a smaller number of securities traded each day, it may be more difficult for the Fund to buy and sell securities on those exchanges. In addition, prices of foreign securities may go up and down more than prices of securities traded in the United States.

Certain Risks of Holding Fund Assets Outside the United States — The Fund generally holds its foreign securities and cash in foreign banks and securities depositories. Some foreign banks and securities depositories may be recently organized or new to the foreign custody business. In addition, there may be limited or no regulatory oversight of their operations. Also, the laws of certain countries limit the Fund’s ability to recover its assets if a foreign bank, depository or issuer of a security, or any of their agents, goes bankrupt. In addition, it is often more expensive for the Fund to buy, sell and hold securities in certain foreign markets than in the United States. The

increased expense of investing in foreign markets reduces the amount the Fund can earn on its investments and typically results in a higher operating expense ratio for the Fund than for investment companies invested only in the United States.

Currency Risk — Securities and other instruments in which the Fund invests may be denominated or quoted in currencies other than the U.S. dollar. For this reason, changes in foreign currency exchange rates can affect the value of the Fund’s portfolio.

Generally, when the U.S. dollar rises in value against a foreign currency, a security denominated in that currency loses value because the currency is worth fewer U.S. dollars. Conversely, when the U.S. dollar decreases in value against a foreign currency, a security denominated in that currency gains value because the currency is worth more U.S. dollars. This risk, generally known as “currency risk,” means that a strong U.S. dollar will reduce returns for U.S. investors while a weak U.S. dollar will increase those returns.

Foreign Economy Risk — The economies of certain foreign markets may not compare favorably with the economy of the United States with respect to such issues as growth of gross national product, reinvestment of capital, resources and balance of payments position. Certain foreign economies may rely heavily on particular industries or foreign capital and are more vulnerable to diplomatic developments, the imposition of economic sanctions against a particular country or countries, changes in international trading patterns, trade barriers and other protectionist or retaliatory measures. Investments in foreign markets may also be adversely affected by governmental actions such as the imposition of capital controls, nationalization of companies or industries, expropriation of assets or the imposition of punitive taxes. In addition, economic conditions, such as volatile currency exchange rates and interest rates, political events, military action and other conditions may, without prior warning, lead to the governments of certain countries, or the U.S. Government with respect to certain countries, prohibiting or imposing substantial restrictions through capital controls and/or sanctions on foreign investments in the capital markets or certain industries in those countries. Capital controls and/or sanctions may include the prohibition of, or restrictions on, the ability to own or transfer currency, securities, derivatives or other assets and may also include retaliatory actions of one government against another government, such as seizure of assets. Any of these actions could severely impair the Fund’s ability to purchase, sell, transfer, receive, deliver or otherwise obtain exposure to foreign securities and assets, including the ability to transfer the Fund’s assets or income back into the United States, and could negatively impact the value and/or liquidity of such assets or otherwise adversely affect the Fund’s operations, causing the Fund to decline in value.

Other potential foreign market risks include foreign exchange controls, difficulties in pricing securities, defaults on foreign government securities, difficulties in enforcing legal judgments in foreign courts and political and social instability. Diplomatic and political developments, including rapid and adverse political changes, social instability, regional conflicts, terrorism and war, could affect the economies, industries and securities and currency markets, and the value of the Fund’s investments, in non-U.S. countries. These factors are extremely difficult, if not impossible, to predict and take into account with respect to the Fund’s investments.

Governmental Supervision and Regulation/Accounting Standards — Many foreign governments do not supervise and regulate stock exchanges, brokers and the sale of securities to the same extent as such regulations exist in the United States. They also may not have laws to protect investors that are comparable to U.S. securities laws. For example, some foreign countries may have no laws or rules against insider trading. Insider trading occurs when a person buys or sells a company’s securities based on material non-public information about that company. In addition, some countries may have legal systems that may make it difficult for the Fund to vote proxies, exercise shareholder rights, and pursue legal remedies with respect to its foreign investments. Accounting standards in other countries are not necessarily the same as in the United States. If the accounting standards in another country do not require as much detail as U.S. accounting standards, it may be harder for Fund management to completely and accurately determine a company’s financial condition.

Settlement Risk — Settlement and clearance procedures in certain foreign markets differ significantly from those in the United States. Foreign settlement and clearance procedures and trade regulations also may involve certain risks (such as delays in payment for or delivery of securities) not typically associated with the settlement of U.S. investments.

At times, settlements in certain foreign countries have not kept pace with the number of securities transactions. These problems may make it difficult for the Fund to carry out transactions. If the Fund cannot settle or is delayed in settling a purchase of securities, it may miss attractive investment opportunities and certain of its assets may be uninvested with no return earned thereon for some period. If the Fund cannot settle or is delayed in settling a sale of securities, it may lose money if the value of the security then declines or, if it has contracted to sell the security to another party, the Fund could be liable for any losses incurred.

Withholding Tax Reclaims Risk — The Fund may file claims to recover foreign withholding taxes on dividend and interest income (if any) received from issuers in certain countries and capital gains on the disposition of stocks or

securities where such withholding tax reclaim is possible. Whether or when the Fund will receive a withholding tax refund is within the control of the tax authorities in such countries. Where the Fund expects to recover withholding taxes, the net asset value of the Fund generally includes accruals for such tax refunds. The Fund regularly evaluates the probability of recovery. If the likelihood of recovery materially decreases, due to, for example, a change in tax regulation or approach in the foreign country, accruals in the Fund’s net asset value for such refunds may be written down partially or in full, which will adversely affect the Fund’s net asset value. Shareholders in the Fund at the time an accrual is written down will bear the impact of the resulting reduction in net asset value regardless of whether they were shareholders during the accrual period. Conversely, if the Fund receives a tax refund that has not been previously accrued, shareholders in the Fund at the time of the successful recovery will benefit from the resulting increase in the Fund’s net asset value. Shareholders who sold their shares prior to such time will not benefit from such increase in the Fund’s net asset value.

European Economic Risk — The European financial markets have recently experienced volatility and adverse trends due to concerns about economic downturns in, or rising government debt levels of, several European countries as well as acts of war in the region. These events may spread to other countries in Europe and may affect the value and liquidity of certain of the Fund’s investments.

Responses to the financial problems by European governments, central banks and others, including austerity measures and reforms, may not work, may result in social unrest and may limit future growth and economic recovery or have other unintended consequences. Further defaults or restructurings by governments and others of their debt could have additional adverse effects on economies, financial markets and asset valuations around the world.

The United Kingdom has withdrawn from the European Union, and one or more other countries may withdraw from the European Union and/or abandon the Euro, the common currency of the European Union. These events and actions have adversely affected, and may in the future adversely affect, the value and exchange rate of the Euro and may continue to significantly affect the economies of every country in Europe, including countries that do not use the Euro and non-European Union member states. The impact of these actions, especially if they occur in a disorderly fashion, is not clear but could be significant and far reaching. In addition, Russia launched a large-scale invasion of Ukraine on February 24, 2022. The extent and duration of the military action, resulting sanctions and resulting future market disruptions in the region are impossible to predict, but could be significant and have a severe adverse effect on the region, including significant negative impacts on the economy and the markets for certain securities and commodities, such as oil and natural gas, as well as other sectors.

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Index-Related Risk — The Fund seeks to achieve a return that corresponds generally to the price and yield performance, before fees and expenses, of the Underlying Index as published by the applicable index provider. There is no assurance that the applicable index provider or any agents that may act on its behalf will compile the Underlying Index accurately, or that the Underlying Index will be determined, composed or calculated accurately. While the applicable index provider provides descriptions of what the Underlying Index is designed to achieve, neither the applicable index provider nor its agents provide any warranty or accept any liability in relation to the quality, accuracy or completeness of the Underlying Index or its related data, and they do not guarantee that the Underlying Index will be in line with the applicable index provider’s methodology. BlackRock’s mandate as described in this prospectus is to manage the Fund consistently with the Underlying Index provided by the applicable index provider to BlackRock. BlackRock does not provide any warranty or guarantee against the applicable index provider’s or any agent’s errors. Errors in respect of the quality, accuracy and completeness of the data used to compile the Underlying Index may occur from time to time and may not be identified and corrected by the applicable index provider for a period of time or at all, particularly where the indices are less commonly used as benchmarks by funds or managers. Such errors may negatively or positively impact the Fund and its shareholders. For example, during a period where the Underlying Index contains incorrect constituents, the Fund would have market exposure to such constituents and would be underexposed to the Underlying Index’s other constituents. Shareholders should understand that any gains from applicable index provider errors will be kept by the Fund and its shareholders and any losses or costs resulting from applicable index provider errors will be borne by the Fund and its shareholders.

Unusual market conditions or other unforeseen circumstances (such as natural disasters, political unrest or war) may impact the applicable index provider or a third-party data provider and could cause the applicable index provider to postpone a scheduled rebalance to the Underlying Index. This could cause the Underlying Index to vary from its normal or expected composition. The postponement of a scheduled rebalance 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, the applicable index provider or its agents may carry out additional ad hoc rebalances to the Underlying Index due to reaching certain weighting constraints, unusual market conditions or corporate events or, for example, to correct an error in the selection of index constituents. When the Underlying Index is rebalanced and the Fund in turn rebalances its portfolio to attempt

to increase the correlation between the Fund’s portfolio and the Underlying Index, any transaction costs and market exposure arising from such portfolio rebalancing will be borne directly by the Fund and its shareholders. Therefore, errors and additional ad hoc rebalances carried out by the applicable index provider or its agents to the Underlying Index may increase the costs to and the tracking error risk of the Fund.

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Representative Sampling Risk (Russell 2000 Small-Cap Index Fund) — Representative sampling is a method of indexing that involves investing in a representative sample of securities that collectively have a similar investment profile to the Russell 2000 and resemble the Russell 2000 in terms of risk factors and other key characteristics. The Fund may or may not hold every security in the Russell 2000. When the Fund deviates from a full replication indexing strategy to utilize a representative sampling strategy, the Fund is subject to an increased risk of tracking error, in that the securities selected in the aggregate for the Fund may not have an investment profile similar to those of the Russell 2000.

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Risk of Investing in the United States (Russell 2000 Small-Cap Index Fund) — A decrease in imports or exports, changes in trade regulations, inflation and/or an economic recession in the United States may have a material adverse effect on the U.S. economy and the securities listed on U.S. exchanges. Proposed and adopted policy and legislative changes in the United States are changing many aspects of financial, commercial, public health, environmental, and other regulation and may have a significant effect on U.S. markets generally, as well as on the value of certain securities. Governmental agencies project that the United States will continue to maintain elevated public debt levels for the foreseeable future. Although elevated debt levels do not necessarily indicate or cause economic problems, elevated public debt service costs may constrain future economic growth.

The United States has developed increasingly strained relations with a number of foreign countries. If relations with certain countries deteriorate, it could adversely affect U.S. issuers as well as non-U.S. issuers that rely on the United States for trade. The United States has also experienced increased internal political discord, as well as significant challenges in managing and containing the outbreak of COVID-19. If these trends were to continue, it may have an adverse impact on the U.S. economy and the issuers in which the Fund invests.

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Small Cap Securities Risk (Russell 2000 Small-Cap Index Fund) — Small cap companies may have limited product lines or markets. They may be less financially secure than larger, more established companies. They may depend on a small number of key personnel. If a product fails or there are other adverse developments, or if management changes, the Fund’s investment in a small cap company may lose substantial value. In addition, it is more difficult to get information on smaller companies, which tend to be less well known, have shorter operating histories, do not have significant ownership by large investors and are followed by relatively few securities analysts.

The securities of small cap companies generally trade in lower volumes and are subject to greater and more unpredictable price changes than larger cap securities or the market as a whole. In addition, small cap securities may be particularly sensitive to changes in interest rates, borrowing costs and earnings. Investing in small cap securities requires a longer term view.

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securities and other instruments held in the Fund’s portfolio and those included in the Underlying Index, pricing differences (including, as applicable, differences between a security’s price at the local market close and the Fund’s valuation of a security at the time of calculation of the Fund’s net asset value), differences in transaction costs, the Fund’s holding of uninvested cash, differences in timing of the accrual of or the valuation of dividends or other distributions, interest, the requirements to maintain pass-through tax treatment, portfolio transactions carried out to minimize the distribution of capital gains to shareholders, changes to the Underlying Index and the cost to the Fund of complying with various new or existing regulatory requirements, among other reasons. These risks may be heightened during times of increased market volatility or other unusual market conditions. In addition, tracking error may result because the Fund incurs fees and expenses, while the Underlying Index does not.

Other Risks of Investing in the Funds

Each Fund may also be subject to certain other non-principal risks associated with its investments and investment strategies, including:

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Borrowing Risk — Borrowing may exaggerate changes in the net asset value of Fund shares and in the return on the Fund’s portfolio. Borrowing will cost the Fund interest expense and other fees. The costs of borrowing may reduce the Fund’s return. Borrowing may cause the Fund to liquidate positions when it may not be advantageous to do so to satisfy its obligations.

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Concentration Risk — The Fund reserves the right to concentrate its investments (i.e., invest 25% or more of its total assets in securities of issuers in a particular industry) to approximately the same extent that the Underlying Index concentrates in a particular industry. To the extent the Fund concentrates in a particular industry, it may be more susceptible to economic conditions and risks affecting that industry.

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Cyber Security Risk — Failures or breaches of the electronic systems of the Fund, the Fund’s adviser, distributor, and other service providers, or the issuers of securities in which the Fund invests have the ability to cause disruptions and negatively impact the Fund’s business operations, potentially resulting in financial losses to the Fund and its shareholders. While the Fund has established business continuity plans and risk management systems seeking to address system breaches or failures, there are inherent limitations in such plans and systems. Furthermore, the Fund cannot control the cyber security plans and systems of the Fund’s service providers or issuers of securities in which the Fund invests.

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Depositary Receipts Risk — Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. In addition to investment risks associated with the underlying issuer, depositary receipts expose the Fund to additional risks associated with the non-uniform terms that apply to depositary receipt programs, credit exposure to the depository bank and to the sponsors and other parties with whom the depository bank establishes the programs, currency risk and the risk of an illiquid market for depositary receipts. The issuers of unsponsored depositary receipts are not obligated to disclose information that is, in the United States, considered material. Therefore, there may be less information available regarding these issuers and there may not be a correlation between such information and the market value of the depositary receipts. While depositary receipts provide an alternative to directly purchasing underlying foreign securities in their respective markets and currencies, they continue to be subject to many of the risks associated with investing directly in foreign securities, including political, economic, and currency risk.

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Derivatives Risk — The Fund’s use of derivatives may increase its costs, reduce the Fund’s returns and/or increase volatility. Derivatives involve significant risks, including:

Leverage Risk — The Fund’s use of derivatives can magnify the Fund’s gains and losses. Relatively small market movements may result in large changes in the value of a derivatives position and can result in losses that greatly exceed the amount originally invested.

Market Risk — Some derivatives are more sensitive to interest rate changes and market price fluctuations than other securities. The Fund could also suffer losses related to its derivatives positions as a result of unanticipated market movements, which losses are potentially unlimited. Finally, BlackRock may not be able to predict correctly the direction of securities prices, interest rates and other economic factors, which could cause the Fund’s derivatives positions to lose value.

Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will be unable or unwilling to fulfill its contractual obligation, and the related risks of having concentrated exposure to such a counterparty.

Illiquidity Risk — The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.

Operational Risk — The use of derivatives includes the risk of potential operational issues, including documentation issues, settlement issues, systems failures, inadequate controls and human error.

Legal Risk — The risk of insufficient documentation, insufficient capacity or authority of counterparty, or legality or enforceability of a contract.

Volatility and Correlation Risk — The Fund’s use of derivatives may reduce the Fund’s returns and/or increase volatility. Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.

Valuation Risk — Valuation for derivatives may not be readily available in the market. Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them. Derivatives may also expose the Fund to greater risk and increase its costs. Certain transactions in derivatives involve substantial leverage risk and may expose the Fund to potential losses that exceed the amount originally invested by the Fund.

Hedging Risk — When a derivative is used as a hedge against a position that the Fund holds, any loss generated by the derivative generally should be substantially offset by gains on the hedged investment, and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences noted below.

Tax Risk — The federal income tax treatment of a derivative may not be as favorable as a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments. As a result, a larger portion of the Fund’s distributions may be treated as ordinary income rather than capital gains. In addition, certain derivatives are subject to mark-to-market or straddle provisions of the Internal Revenue Code. If such provisions are applicable, there could be an increase (or decrease) in the amount of taxable dividends paid by the Fund. In addition, the tax treatment of certain derivatives, such as swaps, is unsettled and may be subject to future legislation, regulation or administrative pronouncements issued by the Internal Revenue Service (the “IRS”).

Regulatory Risk — Derivative contracts are subject to regulation under the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) in the United States and under comparable regimes in Europe, Asia and other non-U.S. jurisdictions. Under the Dodd-Frank Act, with respect to uncleared swaps, swap dealers are required to collect variation margin from the Fund and may be required by applicable regulations to collect initial margin from the Fund. Both initial and variation margin may be comprised of cash and/or securities, subject to applicable regulatory haircuts. Shares of investment companies (other than certain money market funds) may not be posted as collateral under applicable regulations. In addition, regulations adopted by global prudential regulators that are now in effect require certain bank-regulated counterparties and certain of their affiliates to include in certain financial contracts, including many derivatives contracts, terms that delay or restrict the rights of counterparties, such as the Fund, to terminate such contracts, foreclose upon collateral, exercise other default rights or restrict transfers of credit support in the event that the counterparty and/or its affiliates are subject to certain types of resolution or insolvency proceedings. The implementation of these requirements with respect to derivatives, as well as regulations under the Dodd-Frank Act regarding clearing, mandatory trading and margining of other derivatives, may increase the costs and risks to the Fund of trading in these instruments and, as a result, may affect returns to investors in the Fund.

Future regulatory developments may impact the Fund’s ability to invest or remain invested in certain derivatives. Legislation or regulation may also change the way in which the Fund itself is regulated. BlackRock cannot predict the effects of any new governmental regulation that may be implemented on the ability of the Fund to use swaps or any other financial derivative product, and there can be no assurance that any new governmental regulation will not adversely affect the Fund’s ability to achieve its investment objective.

Risks Specific to Certain Derivatives Used by the Fund

Swaps — Swap agreements, including total return swaps that may be referred to as contracts for difference, are two-party contracts entered into for periods ranging from a few days to more than one year. In a standard “swap” transaction, two parties agree to exchange the value(s) or cash flow(s) of one asset for another over a certain period of time. Swap agreements involve the risk that the party with whom the Fund has entered into the swap will default on its obligation to pay the Fund and the risk that the Fund will not be able to meet its obligations to pay the other party to the agreement. Swap agreements may also involve the risk that there is an imperfect correlation between the return on the Fund’s obligation to its counterparty and the return on the referenced asset. In addition, swap agreements are subject to market and illiquidity risk, leverage risk and hedging risk.

Credit Default Swaps — Credit default swaps may have as reference obligations one or more securities that are not currently held by the Fund. The protection “buyer” may be obligated to pay the protection “seller” an up-front payment or a periodic stream of payments over the term of the contract, provided generally that no credit event on a reference obligation has occurred. Credit default swaps involve special risks in addition to those mentioned above because they are difficult to value, are highly susceptible to illiquid investments risk and credit risk, and generally pay a return to the party that has paid the premium only in the event of an actual default by the issuer of the underlying obligation (as opposed to a credit downgrade or other indication of financial difficulty).

Forward Foreign Currency Exchange Contracts — Forward foreign currency exchange transactions are OTC contracts to purchase or sell a specified amount of a specified currency or multinational currency unit at a price and future date set at the time of the contract. Forward foreign currency exchange contracts do not eliminate fluctuations in the value of non-U.S. securities but rather allow the Fund to establish a fixed rate of exchange for a future point in time. This strategy can have the effect of reducing returns and minimizing opportunities for gain.

Futures — Futures are standardized, exchange-traded contracts that obligate a purchaser to take delivery, and a seller to make delivery, of a specific amount of an asset at a specified future date at a specified price. The primary risks associated with the use of futures contracts and options are: (a) the imperfect correlation between the change in market value of the instruments held by the Fund and the price of the futures contract or option; (b) the possible lack of a liquid secondary market for a futures contract and the resulting inability to close a futures contract when desired; (c) losses caused by unanticipated market movements, which are potentially unlimited; (d) the investment adviser’s inability to predict correctly the direction of securities prices, interest rates, currency exchange rates and other economic factors; and (e) the possibility that the counterparty will default in the performance of its obligations.

Options — An option is an agreement that, for a premium payment or fee, gives the option holder (the purchaser) the right but not the obligation to buy (a “call option”) or sell (a “put option”) the underlying asset (or settle for cash in an amount based on an underlying asset, rate, or index) at a specified price (the “exercise price”) during a period of time or on a specified date. Investments in options are considered speculative. When the Fund purchases an option, it may lose the total premium paid for it if the price of the underlying security or other assets decreased, remained the same or failed to increase to a level at or beyond the exercise price (in the case of a call option) or increased, remained the same or failed to decrease to a level at or below the exercise price (in the case of a put option). If a put or call option purchased by the Fund were permitted to expire without being sold or exercised, its premium would represent a loss to the Fund. To the extent that the Fund writes or sells an option, if the decline or increase in the underlying asset is significantly below or above the exercise price of the written option, the Fund could experience a substantial loss.

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Expense Risk — Fund expenses are subject to a variety of factors, including fluctuations in the Fund’s net assets. Accordingly, actual expenses may be greater or less than those indicated. For example, to the extent that the Fund’s net assets decrease due to market declines or redemptions, the Fund’s expenses will increase as a percentage of Fund net assets. During periods of high market volatility, these increases in the Fund’s expense ratio could be significant.

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Illiquid Investments Risk — The Fund may not acquire any illiquid investment if, immediately after the acquisition, the Fund would have invested more than 15% of its net assets in illiquid investments. An illiquid investment is any investment that the Fund reasonably expects cannot be sold or disposed of in current market conditions in seven calendar days or less without the sale or disposition significantly changing the market value of the investment. Liquid investments may become illiquid after purchase by the Fund, particularly during periods of market turmoil. There can be no assurance that a security or instrument that is deemed to be liquid when purchased will continue to be liquid for as long as it is held by the Fund, and any security or instrument held by the Fund may be deemed an illiquid investment pursuant to the Fund’s liquidity risk management program. The Fund’s illiquid investments may reduce the returns of the Fund because it may be difficult to sell the illiquid investments at an advantageous time or price. In addition, if the Fund is limited in its ability to sell illiquid investments during periods when shareholders are redeeming their shares, the Fund will need to sell liquid securities to meet redemption requests and illiquid securities will become a larger portion of the Fund’s holdings. An investment may be illiquid due to, among other things, the lack of an active trading market. To the extent that the Fund’s principal investment strategies involve derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure to the risks associated with illiquid investments. 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. In addition, when there is illiquidity in the market for certain securities, the Fund, due to limitations on illiquid investments, may be subject to purchase and sale restrictions.

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Investment in Other Investment Companies Risk — As with other investments, investments in other investment companies, including ETFs, are subject to market and selection risk. In addition, if the Fund acquires shares of

investment companies, including ones affiliated with the Fund, shareholders bear both their proportionate share of expenses in the Fund (including management and advisory fees) and, indirectly, the expenses of the investment companies (to the extent not offset by BlackRock through waivers). To the extent the Fund is held by an affiliated fund, the ability of the Fund itself to hold other investment companies may be limited.

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Large Shareholder and Large-Scale Redemption Risk — Certain shareholders, including a third-party investor, the Fund’s adviser or an affiliate of the Fund’s adviser, or another entity, may from time to time own or manage a substantial amount of Fund shares or may invest in the Fund and hold its investment for a limited period of time. There can be no assurance that any large shareholder or large group of shareholders would not redeem their investment or that the size of the Fund would be maintained. Redemptions of a large number of Fund shares by these shareholders may adversely affect the Fund’s liquidity and net assets. These redemptions may force the Fund to sell portfolio securities to meet redemption requests when it might not otherwise do so, which may negatively impact the Fund’s NAV and increase the Fund’s brokerage costs and/or accelerate the realization of taxable income and cause the Fund to make taxable distributions to its shareholders earlier than the Fund otherwise would have. In addition, under certain circumstances, non-redeeming shareholders may be treated as receiving a disproportionately large taxable distribution during or with respect to such tax year. The Fund also may be required to sell its more liquid Fund investments to meet a large redemption, in which case the Fund’s remaining assets may be less liquid, more volatile, and more difficult to price. In addition, large redemptions can result in the Fund’s current expenses being allocated over a smaller asset base, which generally results in an increase in the Fund’s expense ratio. Because large redemptions can adversely affect a portfolio manager’s ability to implement a fund’s investment strategy, the Fund also reserves the right to redeem in-kind, subject to certain conditions. In addition, large purchases of Fund shares may adversely affect the Fund’s performance to the extent that the Fund is delayed in investing new cash and is required to maintain a larger cash position than it ordinarily would, diluting its investment returns.

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Leverage Risk — Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. As an open-end investment company registered with the Securities and Exchange Commission (the “SEC”), the Fund is subject to the federal securities laws, including the Investment Company Act, and the rules thereunder. Under Rule 18f-4 under the Investment Company Act, among other things, the Fund must either use derivatives in a limited manner or comply with an outer limit on fund leverage risk based on value-at-risk. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet the applicable requirements of the Investment Company Act and the rules thereunder. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.

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Money Market Securities Risk — If market conditions improve while the Fund has invested some or all of its assets in high quality money market securities, this strategy could result in reducing the potential gain from the market upswing, thus reducing the Fund’s opportunity to achieve its investment objective.

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“New Issues” Risk (Russell 2000 Small-Cap Index Fund) — “New issues” are IPOs of equity securities. Investments in companies that have recently gone public have the potential to produce substantial gains for the Fund. However, there is no assurance that the Fund will have access to profitable IPOs and therefore investors should not rely on these past gains as an indication of future performance. The investment performance of the Fund during periods when it is unable to invest significantly or at all in IPOs may be lower than during periods when the Fund is able to do so. In addition, as the Fund increases in size, the impact of IPOs on the Fund’s performance will generally decrease. Securities issued in IPOs are subject to many of the same risks as investing in companies with smaller market capitalizations. Securities issued in IPOs have no trading history, and information about the companies may be available for very limited periods. In addition, the prices of securities sold in IPOs may be highly volatile or may decline shortly after the IPO. When an IPO is brought to the market, availability may be limited and the Fund may not be able to buy any shares at the offering price, or, if it is able to buy shares, it may not be able to buy as many shares at the offering price as it would like.

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Operational Risk — The Fund is exposed to operational risks arising from a number of factors, including, but not limited to, human errors, processing and communication errors, errors of the Fund’s service providers, counterparties or other third parties, failed or inadequate internal or external processes, and technology or systems failures. The use of certain investment strategies that involve manual or additional processing, such as over-the-counter derivatives, increases these risks. While service providers are required to have appropriate operational risk management policies and procedures, their methods of operational risk management may differ from those of the Fund in the setting of priorities, the personnel and resources available or the effectiveness of relevant controls. The Fund and BlackRock seek to reduce these operational risks through controls, procedures and oversight. However, it is not possible to identify all of the operational risks that may affect the Fund or to develop processes and controls that completely eliminate or mitigate the occurrence or effects of such failures. The Fund, including its performance and continued operation, and its shareholders could be negatively impacted as a result.

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REIT Investment Risk — In addition to the risks facing real estate-related securities, such as a decline in property values due to increasing vacancies, a decline in rents resulting from unanticipated economic, legal or technological developments or a decline in the price of securities of real estate companies due to a failure of borrowers to pay their loans or poor management, investments in REITs involve unique risks. REITs may have limited financial resources, may trade less frequently and in limited volume, may engage in dilutive offerings of securities and may be more volatile than other securities. REIT issuers may also fail to maintain their exemptions from investment company registration or fail to qualify for the “dividends paid deduction” under the Internal Revenue Code, which allows REITs to reduce their corporate taxable income for dividends paid to their shareholders. Ordinary REIT dividends received by the Fund and distributed to the Fund’s shareholders will generally be taxable as ordinary income and will not constitute “qualified dividend income.” However, for tax years beginning after December 31, 2017 and before January 1, 2026, a non-corporate taxpayer who is a direct REIT shareholder may claim a 20% “qualified business income” deduction for ordinary REIT dividends, and a regulated investment company may report dividends as eligible for this deduction to the extent the regulated investment company’s income is derived from ordinary REIT dividends (reduced by allocable regulated investment company expenses). A shareholder may treat the dividends as such provided the regulated investment company and the shareholder satisfy applicable holding period requirements.

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Reliance on Advisor Risk — The Fund is dependent upon services and resources provided by BlackRock, and therefore BlackRock’s parent, BlackRock, Inc. BlackRock is not required to devote its full time to the business of the Fund and there is no guarantee or requirement that any investment professional or other employee of BlackRock will allocate a substantial portion of his or her time to the Fund. The loss of, or changes in, BlackRock’s personnel could have a negative effect on the performance or the continued operation of the Fund.

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Repurchase Agreements and Purchase and Sale Contracts Risk — If the other party to a repurchase agreement or purchase and sale contract defaults on its obligation under the agreement, the Fund may suffer delays and incur costs or lose money in exercising its rights under the agreement. If the seller fails to repurchase the security in either situation and the market value of the security declines, the Fund may lose money.

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Restricted Securities Risk — Limitations on the resale of restricted securities may have an adverse effect on their marketability, and may prevent the Fund from disposing of them promptly at advantageous prices. Restricted securities may not be listed on an exchange and may have no active trading market. In order to sell such securities, the Fund may have to bear the expense of registering the securities for resale and the risk of substantial delays in effecting the registration. Other transaction costs may be higher for restricted securities than unrestricted securities. Restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility. Also, the Fund may get only limited information about the issuer of a given restricted security, and therefore may be less able to predict a loss. Certain restricted securities may involve a high degree of business and financial risk and may result in substantial losses to the Fund.

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Securities Lending Risk — The Fund may engage in securities lending. Securities lending involves 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. These events could also trigger adverse tax consequences for the Fund. BlackRock Institutional Trust Company, N.A.(“BTC”), the Fund’s securities lending agent, will consider the tax impact to shareholders of substitute payments for dividends when managing the Fund’s securities lending program.

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Short Sales Risk — Because making short sales in securities that it does not own exposes the Fund to the risks associated with those securities, such short sales involve speculative exposure risk. The Fund will incur a loss as a result of a short sale if the price of the security increases between the date of the short sale and the date on which the Fund replaces the security sold short. The Fund will realize a gain if the security declines in price between those dates. As a result, if the Fund makes short sales in securities that increase in value, it will likely underperform similar funds that do not make short sales in securities they do not own. There can be no assurance that the Fund will be able to close out a short sale position at any particular time or at an acceptable price. Although the Fund’s gain is limited to the amount at which it sold a security short, its potential loss is limited only by the maximum attainable price of the security, less the price at which the security was sold. The Fund may also pay transaction costs and borrowing fees in connection with short sales.

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Valuation Risk — The price the Fund could receive upon the sale of any particular portfolio investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair valuation methodology or a price provided by an independent pricing service. As a result, the price received upon the sale of an investment may be less than the value ascribed by the Fund, and the Fund could realize a greater than expected loss or lesser than expected gain upon the sale of the investment. Pricing services that value fixed-income securities generally utilize a range of market-based and security-specific inputs and

Share Classes at a Glance1

	Investor A Shares	Institutional Shares
Availability	Generally available through Financial Intermediaries.	Limited to certain investors, including: •Individuals and “Institutional Investors,” which include, but are not limited to, endowments, foundations, family offices, local, city and state governmental institutions, corporations and insurance company separate accounts, who may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Distributor to purchase such shares. •Employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs), state sponsored 529 college savings plans, collective trust funds, investment companies or other pooled investment vehicles, unaffiliated thrifts and unaffiliated banks and trust companies, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Distributor to purchase such shares. •Employees, officers and directors/trustees of BlackRock or its affiliates and immediate family members of such persons, if they open an account directly with BlackRock. •Participants in certain programs sponsored by BlackRock or its affiliates or other Financial Intermediaries. •Tax-qualified accounts for insurance agents that are registered representatives of an insurance company’s broker-dealer that has entered into an agreement with the Distributor to offer Institutional Shares, and the family members of such persons. •Clients investing through Financial Intermediaries that have entered into an agreement with the Distributor to offer such shares on a platform that charges a transaction based sales commission outside of the Fund. •Clients investing through a self-directed IRA brokerage account program sponsored by a retirement plan record-keeper, provided that such program offers only mutual fund options and that the program maintains an account with the Fund on an omnibus basis.

	Investor A Shares	Institutional Shares
Minimum Investment	$1,000 for all accounts except: •$50, if establishing an Automatic Investment Plan (“AIP”). •There is no investment minimum for employer- sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs). •There is no investment minimum for certain fee- based programs.	There is no investment minimum for: •Employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs), state sponsored 529 college savings plans, collective trust funds, investment companies or other pooled investment vehicles, unaffiliated thrifts and unaffiliated banks and trust companies. •Employees, officers and directors/trustees of BlackRock or its affiliates and immediate family members of such persons, if they open an account directly with BlackRock. •Clients of Financial Intermediaries that: (i) charge such clients a fee for advisory, investment consulting, or similar services or (ii) have entered into an agreement with the Distributor to offer Institutional Shares through a no-load program or investment platform. •Clients investing through a self-directed IRA brokerage account program sponsored by a retirement plan record-keeper, provided that such program offers only mutual fund options and that the program maintains an account with the Fund on an omnibus basis. $2 million for individuals and Institutional Investors. $1,000 investment minimum for: •Clients investing through Financial Intermediaries that offer such shares on a platform that charges a transaction based sales commission outside of the Fund. •Tax-qualified accounts for insurance agents that are registered representatives of an insurance company’s broker-dealer that has entered into an agreement with the Distributor to offer Institutional Shares, and the family members of such persons.
Initial Sales Charge?	No. Entire purchase price is invested in shares of the Fund.	No. Entire purchase price is invested in shares of the Fund.
Deferred Sales Charge?	No.	No.
Distribution and Service (12b-1) Fees?	No Distribution Fee. 0.25% Annual Service Fee.	No.
Redemption Fees?	No.	No.
Conversion to Investor A Shares?	N/A	No.
Advantage	Generally available.	No annual service fee.
Disadvantage	Annual service fee.	Limited availability.

Please see “Details About the Share Classes” for more information about each share class.

The following pages will cover the additional details of each share class, including the eligibility requirements to purchase Institutional Shares.

More information about existing sales charge reductions and waivers is available free of charge in a clear and prominent format via hyperlink at www.blackrock.com and in the SAI, which is available on the website or on request.

Details About the Share Classes

Investor A Shares

Investor A Shares of each Fund pay an ongoing service fee of 0.25% per year. The Distributor normally pays the annual 0.25% Investor A Shares service fee to dealers on a monthly basis.

Institutional Shares

Institutional Shares are not subject to any sales charge. Only certain investors are eligible to buy Institutional Shares. Your Financial Intermediary can help you determine whether you are eligible to buy Institutional Shares. Each Fund may permit a lower initial investment for certain investors if their purchase, combined with purchases by other investors received together by a Fund, meets the minimum investment requirement.

Institutional Shares may also be available on certain brokerage platforms. An investor transacting in Institutional Shares on such brokerage platforms through a broker acting as an agent for the investor may be required to pay a commission and/or other forms of compensation to the broker. Shares of the Fund are available in other share classes that have different fees and expenses.

Eligible Institutional Shares investors include the following:

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Individuals and “Institutional Investors” with a minimum initial investment of $2 million who may purchase shares of a Fund through a Financial Intermediary that has entered into an agreement with the Distributor to purchase such shares;

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Clients of Financial Intermediaries that: (i) charge such clients a fee for advisory, investment consulting, or similar services or (ii) have entered into an agreement with the Distributor to offer Institutional Shares through a no-load program or investment platform, in each case, with no minimum initial investment;

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Clients investing through Financial Intermediaries that have entered into an agreement with the Distributor to offer such shares on a platform that charges a transaction based sales commission outside of the Fund, with a minimum initial investment of $1,000;

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Employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs or SARSEPs), state sponsored 529 college savings plans, collective trust funds, investment companies or other pooled investment vehicles, unaffiliated thrifts and unaffiliated banks and trust companies, each of which is not subject to any minimum initial investment and may purchase shares of a Fund through a Financial Intermediary that has entered into an agreement with the Distributor to purchase such shares;

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Trust department clients of Bank of America, N.A. and its affiliates for whom they (i) act in a fiduciary capacity (excluding participant directed employee benefit plans); (ii) otherwise have investment discretion; or (iii) act as custodian for at least $2 million in assets, who are not subject to any minimum initial investment;

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Holders of certain Bank of America Corporation (“BofA Corp.”) sponsored unit investment trusts (“UITs”) who reinvest dividends received from such UITs in shares of a Fund, who are not subject to any minimum initial investment;

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Employees, officers and directors/trustees of BlackRock, Inc., mutual funds sponsored and advised by BlackRock or its affiliates (“BlackRock Funds”), BofA Corp., Barclays PLC or their respective affiliates and immediate family members of such persons, if they open an account directly with BlackRock, who are not subject to any minimum initial investment;

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Tax-qualified accounts for insurance agents that are registered representatives of an insurance company’s broker-dealer that has entered into an agreement with the Distributor to offer Institutional Shares, and the family members of such persons; and

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Clients investing through a self-directed IRA brokerage account program sponsored by a retirement plan record-keeper, provided that such program offers only mutual fund options and that the program maintains an account with a Fund on an omnibus basis.

The Funds reserve the right to modify or waive the above-stated policies at any time.

Right of Accumulation

Investors have a “right of accumulation” under which any of the following may be combined with the amount of the current purchase in determining whether an investor qualifies for a breakpoint and a reduced front-end sales charge:

The current value of an investor’s existing Investor A and A1, Investor C, Investor P, Institutional, Class K and Premier Shares in most BlackRock Funds,

ii.

The current value of an investor’s existing shares of certain unlisted closed-end management investment companies sponsored and advised by BlackRock or its affiliates and

iii.

The investment in the BlackRock CollegeAdvantage 529 Program by the investor or by or on behalf of the investor’s spouse and children.

Financial Intermediaries may value current holdings of their customers differently for purposes of determining whether an investor qualifies for a breakpoint and a reduced front-end sales charge, although customers of the same Financial Intermediary will be treated similarly. In order to use this right, the investor must alert BlackRock to the existence of any previously purchased shares.

Distribution and Shareholder Servicing Payments

Plan Payments

The Corporation, on behalf of the Funds, has adopted a plan (the “Plan”) pursuant to Rule 12b-1 under the Investment Company Act with respect to the Investor Shares that allows a Fund to pay distribution fees for the sale of its shares and/or shareholder servicing fees for certain services provided to its shareholders. Institutional and Investor A Shares do not pay distribution fees.

Under the Plan, the Funds pay shareholder servicing fees (also referred to as general shareholder liaison services fees) to Financial Intermediaries for providing support services to their customers who own Investor Shares of the Fund. The shareholder servicing fee payment is calculated as a percentage of the average daily net asset value of Investor Shares of the Fund. All Investor A Shares pay this shareholder servicing fee. Institutional Shares do not pay a shareholder servicing fee.

In return for the shareholder servicing fee, Financial Intermediaries (including BlackRock) may provide one or more of the following services to their customers who own Investor Shares:

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Answering customer inquiries regarding account status and history, the manner in which purchases, exchanges and redemptions or repurchases of shares may be effected and certain other matters pertaining to the customers’ investments;

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Assisting customers in designating and changing dividend options, account designations and addresses; and

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Providing other similar shareholder liaison services.

The shareholder servicing fees payable pursuant to the Plan are paid to compensate Financial Intermediaries for the administration and servicing of shareholder accounts and are not costs which are primarily intended to result in the sale of a Fund’s shares. Because the fees paid by a Fund under the Plan are paid out of Fund assets on an ongoing basis, over time these fees will increase the cost of your investment and may cost you more than paying other types of sales charges. For more information on the Plan, including a complete list of services provided thereunder, see the SAI.

Other Payments by the Funds

In addition to fees that a Fund may pay to a Financial Intermediary pursuant to the Plan and fees a Fund pays to its transfer agent, BNY Mellon Investment Servicing (US) Inc. (the “Transfer Agent”), BlackRock, on behalf of a Fund, may enter into non-Plan agreements with affiliated and unaffiliated Financial Intermediaries pursuant to which the Fund will pay a Financial Intermediary for administrative, networking, recordkeeping, sub-transfer agency, sub-accounting and/or shareholder services. These non-Plan payments are generally based on either (1) a percentage of the average daily net assets of Fund shareholders serviced by a Financial Intermediary or (2) a fixed dollar amount for each account serviced by a Financial Intermediary. The aggregate amount of these payments may be substantial.

Other Payments by BlackRock

From time to time, BlackRock, the Distributor or their affiliates also may pay a portion of the fees for administrative, networking, recordkeeping, sub-transfer agency, sub-accounting and shareholder services described above at its or their own expense and out of its or their profits. BlackRock, the Distributor and their affiliates may also compensate affiliated and unaffiliated Financial Intermediaries for the sale and distribution of shares of the Funds. These payments would be in addition to the Fund payments described in this prospectus and may be a fixed dollar amount, may be based on the number of customer accounts maintained by the Financial Intermediary, may be based on a percentage of the value of shares sold to, or held by, customers of the Financial Intermediary or may be calculated on another basis. The aggregate amount of these payments by BlackRock, the Distributor and their affiliates may be substantial and, in some circumstances, may create an incentive for a Financial Intermediary, its employees or associated persons to recommend or sell shares of a Fund to you.

Please contact your Financial Intermediary for details about payments it may receive from a Fund or from BlackRock, the Distributor or their affiliates. For more information, see the SAI.

How to Buy, Sell, Exchange and Transfer Shares

The chart on the following pages summarizes how to buy, sell, exchange and transfer shares through your Financial Intermediary. You may also buy, sell, exchange and transfer shares through BlackRock if your account is held directly with BlackRock. To learn more about buying, selling, exchanging or transferring shares through BlackRock, call (800) 441-7762. Because the selection of a mutual fund involves many considerations, your Financial Intermediary may help you with this decision.

With certain limited exceptions, the Funds are generally available only to investors residing in the United States and may not be distributed by a foreign Financial Intermediary. Under this policy, in order to accept new accounts or additional investments (including by way of exchange from another BlackRock Fund) into existing accounts, the Funds generally require that (i) a shareholder that is a natural person be a U.S. citizen or resident alien, in each case residing within the United States or a U.S. territory (including APO/FPO/DPO addresses), and have a valid U.S. taxpayer identification number, and (ii) a Financial Intermediary or a shareholder that is an entity be domiciled in the United States and have a valid U.S. taxpayer identification number or be domiciled in a U.S. territory and have a valid U.S. taxpayer identification number or IRS Form W-8. Any existing account that is updated to reflect a non-U.S. address will also be restricted from making additional investments.

Each Fund may reject any purchase order, modify or waive the minimum initial or subsequent investment requirements for any shareholders and suspend and resume the sale of any share class of the Fund at any time for any reason. In addition, the Funds may waive certain requirements regarding the purchase, sale, exchange or transfer of shares described below.

Under certain circumstances, if no activity occurs in an account within a time period specified by state law, a shareholder’s shares in a Fund may be transferred to that state.

How to Buy Shares

	Your Choices	Important Information for You to Know
Initial Purchase	First, select the share class appropriate for you	Refer to the “Share Classes at a Glance” table in this prospectus (be sure to read this prospectus carefully). When you place your initial order, you must indicate which share class you select (if you do not specify a share class and do not qualify to purchase Institutional Shares, you will receive Investor A Shares). Certain factors, such as the amount of your investment, your time frame for investing and your financial goals, may affect which share class you choose. Your Financial Intermediary can help you determine which share class is appropriate for you.
	Next, determine the amount of your investment	Refer to the minimum initial investment in the “Share Classes at a Glance” table of this prospectus.
	Have your Financial Intermediary submit your purchase order	The price of your shares is based on the next calculation of the Fund’s net asset value after your order is placed. Any purchase orders placed prior to the close of business on the New York Stock Exchange (the “NYSE”) (generally 4:00 p.m. Eastern time) will be priced at the net asset value determined that day. Certain Financial Intermediaries, however, may require submission of orders prior to that time. Purchase orders placed after that time will be priced at the net asset value determined on the next business day. A broker-dealer or financial institution maintaining the account in which you hold shares may charge a separate account, service or transaction fee on the purchase or sale of Fund shares that would be in addition to the fees and expenses shown in the Fund’s “Fees and Expenses” table. The Fund may reject any order to buy shares and may suspend the sale of shares at any time. Certain Financial Intermediaries may charge a processing fee to confirm a purchase.

	Your Choices	Important Information for You to Know
Initial Purchase (continued)	Or contact BlackRock (for accounts held directly with BlackRock)	To purchase shares directly from BlackRock, call (800) 441-7762 and request a new account application. Mail the completed application along with a check payable to “BlackRock Funds” to the Transfer Agent at the address on the application. The Fund limits purchases by personal check to $500,000 per trade.
Add to Your Investment	Purchase additional shares	For Investor A Shares, the minimum investment for additional purchases is generally $50 for all accounts (with the exception of certain employer-sponsored retirement plans which may have a lower minimum for additional purchases). The minimums for additional purchases may be waived under certain circumstances. Institutional Shares have no minimum for additional purchases.
	Have your Financial Intermediary submit your purchase order for additional shares	To purchase additional shares you may contact your Financial Intermediary. For more details on purchasing by Internet see below.
	Or contact BlackRock (for accounts held directly with BlackRock)	Purchase by Telephone: Call (800) 441-7762 and speak with one of our representatives. The Fund has the right to reject any telephone request for any reason. Purchase in Writing: You may send a written request to BlackRock at the address on the back cover of this prospectus. Purchase by VRU: Investor A Shares may also be purchased by use of the Fund’s automated voice response unit (“VRU”) service at (800) 441-7762. Purchase by Internet: You may purchase your shares and view activity in your account by logging onto the BlackRock website at www.blackrock.com. Purchases made on the Internet using the Automated Clearing House (“ACH”) will have a trade date that is the day after the purchase is made. Certain institutional clients’ purchase orders of Institutional Shares placed by wire prior to the close of business on the NYSE will be priced at the net asset value determined that day. Contact your Financial Intermediary or BlackRock for further information. The Fund limits Internet purchases in shares of the Fund to $25,000 per trade. Different maximums may apply to certain institutional investors. Please read the On-Line Services Disclosure Statement and User Agreement, the Terms and Conditions page and the Consent to Electronic Delivery Agreement (if you consent to electronic delivery), before attempting to transact online. The Fund employs reasonable procedures to confirm that transactions entered over the Internet are genuine. By entering into the User Agreement with the Fund in order to open an account through the website, the shareholder waives any right to reclaim any losses from the Fund or any of its affiliates incurred through fraudulent activity.
	Acquire additional shares by reinvesting dividends and capital gains	All dividends and capital gains distributions are automatically reinvested in shares of each Fund at net asset value. To make any changes to your dividend and/or capital gains distributions options, please call (800) 441-7762 or contact your Financial Intermediary (if your account is not held directly with BlackRock).
	Participate in the AIP	BlackRock’s AIP allows you to invest a specific amount on a periodic basis from your checking or savings account into your investment account. Refer to the “Account Services and Privileges” section of this prospectus for additional information.
How to Pay for Shares	Making payment for purchases	Payment for an order must be made in Federal funds or other immediately available funds by the time specified by your Financial Intermediary, but in no event later than 4:00 p.m. (Eastern time) on the first business day following BlackRock’s receipt of the order. If payment is not received by this time, the order will be canceled and you and your Financial Intermediary will be responsible for any loss to the Fund. For shares purchased directly from the Fund, a check payable to BlackRock Funds which bears the name of the Fund must accompany a completed purchase application. The Fund limits purchases by personal check to $500,000 per trade. There is a $20 fee for each purchase check that is returned due to insufficient funds. The Fund does not

	Your Choices	Important Information for You to Know
How to Pay for Shares (continued)	Making payment for purchases (continued)	accept third-party checks. You may also wire Federal funds to the Fund to purchase shares, but you must call (800) 441-7762 before doing so to confirm the wiring instructions.

How to Sell Shares

	Your Choices	Important Information for You to Know
Full or Partial Redemption of Shares	Have your Financial Intermediary submit your sales order	You can make redemption requests through your Financial Intermediary. Shareholders should indicate whether they are redeeming Investor A or Institutional Shares. The price of your shares is based on the next calculation of the Fund’s net asset value after your order is placed. For your redemption request to be priced at the net asset value on the day of your request, you must submit your request to your Financial Intermediary prior to that day’s close of business on the NYSE (generally 4:00 p.m. Eastern time). Certain Financial Intermediaries, however, may require submission of orders prior to that time. Any redemption request placed after that time will be priced at the net asset value at the close of business on the next business day. Regardless of the method the Fund uses to make payment of your redemption proceeds (check, wire or ACH), your redemption proceeds typically will be sent one to two business days after your request is submitted, but in any event, within seven days. Certain Financial Intermediaries may charge a fee to process a redemption of shares. The Fund may reject an order to sell shares under certain circumstances.
	Selling shares held directly with BlackRock	Methods of Redeeming Redeem by Telephone: You may sell Investor A Shares held directly with BlackRock by telephone request if certain conditions are met and if the amount being sold is less than (i) $100,000 for payments by check or (ii) $250,000 for payments through ACH or wire transfer. Certain redemption requests, such as those in excess of these amounts, must be in writing with a medallion signature guarantee. For Institutional Shares, certain redemption requests may require written instructions with a medallion signature guarantee. Call (800) 441-7762 for details. You can obtain a medallion signature guarantee stamp from a bank, securities dealer, securities broker, credit union, savings and loan association, national securities exchange or registered securities association. A notary public seal will not be acceptable. The Fund, its administrator and the Distributor will employ reasonable procedures to confirm that instructions communicated by telephone are genuine. The Fund and its service providers will not be liable for any loss, liability, cost or expense for acting upon telephone instructions that are reasonably believed to be genuine in accordance with such procedures. The Fund may refuse a telephone redemption request if it believes it is advisable to do so. During periods of substantial economic or market change, telephone redemptions may be difficult to complete. Please find alternative redemption methods below. Redeem by VRU: Investor A Shares may also be redeemed by use of the Fund’s automated VRU service. Payment for Investor A Shares redeemed by the VRU service may be made for non-retirement accounts in amounts up to $25,000, either through check, ACH or wire. Redeem by Internet: You may redeem in your account by logging onto the BlackRock website at www.blackrock.com. Proceeds from Internet redemptions may be sent via check, ACH or wire to the bank account of record. Payment for Investor A Shares redeemed by Internet may be made for non-retirement accounts in amounts up to $25,000, either through check, ACH or wire. Different maximums may apply to investors in Institutional Shares.

	Your Choices	Important Information for You to Know
Full or Partial Redemption of Shares (continued)	Selling shares held directly with BlackRock (continued)	Redeem in Writing: You may sell shares held with BlackRock by writing to BlackRock, P.O. Box 534429, Pittsburgh, Pennsylvania 15253-4429 or for overnight delivery, Attention: 534429, 500 Ross Street 154- 0520, Pittsburgh, Pennsylvania 15262. All shareholders on the account must sign the letter. A medallion signature guarantee will generally be required but may be waived in certain limited circumstances. You can obtain a medallion signature guarantee stamp from a bank, securities dealer, securities broker, credit union, savings and loan association, national securities exchange or registered securities association. A notary public seal will not be acceptable. If you hold stock certificates, return the certificates with the letter. Proceeds from redemptions may be sent via check, ACH or wire to the bank account of record. Payment of Redemption Proceeds Redemption proceeds may be paid by check or, if the Fund has verified banking information on file, through ACH or by wire transfer. Payment by Check: BlackRock will normally mail redemption proceeds within three business days following receipt of a properly completed request, but in any event within seven days. Shares can be redeemed by telephone and the proceeds sent by check to the shareholder at the address on record. Shareholders will pay $15 for redemption proceeds sent by check via overnight mail. You are responsible for any additional charges imposed by your bank for this service. The Fund reserves the right to reinvest any dividend or distribution amounts (e.g., income dividends or capital gains) which you have elected to receive by check should your check be returned as undeliverable or remain uncashed for more than 6 months. No interest will accrue on amounts represented by uncashed checks. Your check will be reinvested in your account at the net asset value next calculated, on the day of the investment. When reinvested, those amounts are subject to the risk of loss like any fund investment. If you elect to receive distributions in cash and a check remains undeliverable or uncashed for more than 6 months, your cash election may also be changed automatically to reinvest and your future dividend and capital gains distributions will be reinvested in the Fund at the net asset value as of the date of payment of the distribution. Payment by Wire Transfer: Payment for redeemed shares for which a redemption order is received before 4:00 p.m. (Eastern time) on a business day is normally made in Federal funds wired to the redeeming shareholder on the next business day, provided that the Fund’s custodian is also open for business. Payment for redemption orders received after 4:00 p.m. (Eastern time) or on a day when the Fund’s custodian is closed is normally wired in Federal funds on the next business day following redemption on which the Fund’s custodian is open for business. The Fund reserves the right to wire redemption proceeds within seven days after receiving a redemption order if, in the judgment of the Fund, an earlier payment could adversely affect the Fund. If a shareholder has given authorization for expedited redemption, shares can be redeemed by Federal wire transfer to a single previously designated bank account. Shareholders will pay $7.50 for redemption proceeds sent by Federal wire transfer. You are responsible for any additional charges imposed by your bank for this service. No charge for wiring redemption payments with respect to Institutional Shares is imposed by the Fund. The Fund is not responsible for the efficiency of the Federal wire system or the shareholder’s firm or bank. To change the name of the single, designated bank account to receive wire redemption proceeds, it is necessary to send a written request to the Fund at the address on the back cover of this prospectus. Payment by ACH: Redemption proceeds may be sent to the shareholder’s bank account (checking or savings) via ACH. Payment for

	Your Choices	Important Information for You to Know
Full or Partial Redemption of Shares (continued)	Selling shares held directly with BlackRock (continued)	redeemed shares for which a redemption order is received before 4:00 p.m. (Eastern time) on a business day is normally sent to the redeeming shareholder the next business day, with receipt at the receiving bank within the next two business days (48-72 hours), provided that the Fund’s custodian is also open for business. Payment for redemption orders received after 4:00 p.m. (Eastern time) or on a day when the Fund’s custodian is closed is normally sent on the next business day following redemption on which the Fund’s custodian is open for business. The Fund reserves the right to send redemption proceeds within seven days after receiving a redemption order if, in the judgment of the Fund, an earlier payment could adversely affect the Fund. No charge for sending redemption payments via ACH is imposed by the Fund. *** If you make a redemption request before the Fund has collected payment for the purchase of shares, the Fund may delay mailing your proceeds. This delay will usually not exceed ten days.
Redemption Proceeds		Under normal circumstances, a Fund expects to meet redemption requests by using cash or cash equivalents in its portfolio or by selling portfolio assets to generate cash. During periods of stressed market conditions, when a significant portion of the Fund’s portfolio may be comprised of less-liquid investments, the Fund may be more likely to limit cash redemptions and may determine to pay redemption proceeds by (i) borrowing under a line of credit it has entered into with a group of lenders, (ii) borrowing from another BlackRock Fund pursuant to an interfund lending program, to the extent permitted by the Fund’s investment policies and restrictions as set forth in the SAI, and/or (iii) transferring portfolio securities in-kind to you. The SAI includes more information about the Fund’s line of credit and interfund lending program, to the extent applicable. If the Fund pays redemption proceeds by transferring portfolio securities in-kind to you, you may pay transaction costs to dispose of the securities, and you may receive less for them than the price at which they were valued for purposes of redemption.

How to Exchange Shares or Transfer Your Account

	Your Choices	Important Information for You to Know
Exchange Privilege	Selling shares of one BlackRock Fund to purchase shares of another BlackRock Fund (“exchanging”)	Investor or Institutional Shares of the Fund are generally exchangeable for shares of the same class of another BlackRock Fund, to the extent such shares are offered by your Financial Intermediary. You can exchange $1,000 or more of Investor Shares from one fund into the same class of another fund which offers that class of shares (you can exchange less than $1,000 of Investor Shares if you already have an account in the fund into which you are exchanging). Investors who currently own Institutional Shares of the Fund may make exchanges into Institutional Shares of other BlackRock Funds except for investors holding shares through certain client accounts at Financial Intermediaries that are omnibus with the Fund and do not meet applicable minimums. There is no required minimum amount with respect to exchanges of Institutional Shares. You may only exchange into a share class and fund that are open to new investors or in which you have a current account if the fund is closed to new investors. Some of the BlackRock Funds impose a different initial or deferred sales charge schedule. Therefore the exchange of Investor A Shares may be subject to that sales charge. Investor A Shares of the Fund that were obtained with the exchange privilege and that originally were shares of a BlackRock Fund that were subject to a sales charge can be exchanged for Investor A Shares of another BlackRock Fund based on their respective NAVs. The contingent deferred sales charge (“CDSC”) will continue to be measured from the date of the original purchase. The CDSC schedule applicable to your original purchase will apply to

	Your Choices	Important Information for You to Know
Exchange Privilege (continued)	Selling shares of one BlackRock Fund to purchase shares of another BlackRock Fund (“exchanging”) (continued)	the shares you receive in the exchange and any subsequent exchange. To exercise the exchange privilege, you may contact your Financial Intermediary. Alternatively, if your account is held directly with BlackRock, you may: (i) call (800) 441-7762 and speak with one of our representatives, (ii) make the exchange via the Internet by accessing your account online at www.blackrock.com or (iii) send a written request to the Fund at the address on the back cover of this prospectus. Please note, if you indicated on your new account application that you did not want the Telephone Exchange Privilege, you will not be able to place exchanges via the telephone until you update this option either in writing or by calling (800) 441-7762. The Fund has the right to reject any telephone request for any reason. Although there is currently no limit on the number of exchanges that you can make, the exchange privilege may be modified or terminated at any time in the future. The Fund may suspend or terminate your exchange privilege at any time for any reason, including if a Fund believes, in its sole discretion, that you are engaging in market timing activities. See “Short-Term Trading Policy” below. For U.S. federal income tax purposes a share exchange is a taxable event and a capital gain or loss may be realized. Please consult your tax adviser or other Financial Intermediary before making an exchange request.
Transfer Shares to Another Financial Intermediary	Transfer to a participating Financial Intermediary	You may transfer your shares of the Fund only to another Financial Intermediary that has entered into an agreement with the Distributor. Certain shareholder services may not be available for the transferred shares. All future trading of these assets must be coordinated by the receiving firm. If your account is held directly with BlackRock, you may call (800) 441-7762 with any questions; otherwise please contact your Financial Intermediary to accomplish the transfer of shares.
	Transfer to a non-participating Financial Intermediary	You must either: •Transfer your shares to an account with the Fund; or •Sell your shares. If your account is held directly with BlackRock, you may call (800) 441-7762 with any questions; otherwise please contact your Financial Intermediary to accomplish the transfer of shares.

Account Services and Privileges

The following table provides examples of account services and privileges available in your BlackRock account. Certain of these account services and privileges are only available to shareholders of Investor Shares whose accounts are held directly with BlackRock. If your account is held directly with BlackRock, please call (800) 441-7762 or visit www.blackrock.com for additional information as well as forms and applications. Otherwise, please contact your Financial Intermediary for assistance in requesting one or more of the following services and privileges.

Automatic Investment Plan	Allows systematic investments on a periodic basis from your checking or savings account.	BlackRock’s AIP allows you to invest a specific amount on a periodic basis from your checking or savings account into your investment account. You may apply for this option upon account opening or by completing the AIP application. The minimum investment amount for an automatic investment is $50 per portfolio.
Dividend Allocation Plan	Automatically invests your distributions into another BlackRock Fund of your choice pursuant to your instructions, without any fees or sales charges.	Dividend and capital gains distributions may be reinvested in your account to purchase additional shares or paid in cash. Using the Dividend Allocation Plan, you can direct your distributions to your bank account (checking or savings), to purchase shares of another fund at BlackRock without any fees or sales charges, or by check to a special payee. Please call (800) 441-7762 for details. If investing in another BlackRock Fund, the receiving fund must be open to new purchases.

EZ Trader	Allows an investor to purchase or sell Investor A Shares by telephone or over the Internet through ACH.	(NOTE: This option is offered to shareholders whose accounts are held directly with BlackRock. Please speak with your Financial Intermediary if your account is held elsewhere.) Prior to establishing an EZ Trader account, please contact your bank to confirm that it is a member of the ACH system. Once confirmed, complete an application, making sure to include the appropriate bank information, and return the application to the address listed on the form. Prior to placing a telephone or Internet purchase or sale order, please call (800) 441-7762 to confirm that your bank information has been updated on your account. Once this is established, you may place your request to sell shares with the Fund by telephone or Internet. Proceeds will be sent to your pre-designated bank account.
Systematic Exchange Plan	This feature can be used by investors to systematically exchange money from one fund to up to four other funds.	A minimum of $10,000 in the initial BlackRock Fund is required, and investments in any additional funds must meet minimum initial investment requirements.
Systematic Withdrawal Plan (“SWP”)	This feature can be used by investors who want to receive regular distributions from their accounts.	To start an SWP, a shareholder must have a current investment of $10,000 or more in a BlackRock Fund. Shareholders can elect to receive cash payments of $50 or more at any interval they choose. Shareholders may sign up by completing the SWP Application Form, which may be obtained from BlackRock. Shareholders should realize that if withdrawals exceed income the invested principal in their account will be depleted. To participate in the SWP, shareholders must have their dividends reinvested. Shareholders may change or cancel the SWP at any time, with a minimum of 24 hours’ notice. If a shareholder purchases additional Investor A Shares of a fund at the same time he or she redeems shares through the SWP, that investor may lose money because of any applicable sales charge. Ask your Financial Intermediary for details.

Funds’ Rights

Each Fund may:

◼

Suspend the right of redemption if trading is halted or restricted on the NYSE or under other emergency conditions described in the Investment Company Act;

◼

Postpone the date of payment upon redemption if trading is halted or restricted on the NYSE or under other emergency conditions described in the Investment Company Act or if a redemption request is made before the Fund has collected payment for the purchase of shares;

◼

Redeem shares for property other than cash as may be permitted under the Investment Company Act; and

◼

Redeem shares involuntarily in certain cases, such as when the value of a shareholder account falls below a specified level.

Note on Low Balance Accounts. Because of the high cost of maintaining smaller shareholder accounts, BlackRock has set a minimum balance of $500 in each Fund position you hold within your account (“Fund Minimum”), and may redeem the shares in your account if the net asset value of those shares in your account falls below $500 for any reason, including market fluctuation.

You will be notified that the value of your account is less than the Fund Minimum before the Fund makes any involuntary redemption. This notification will provide you with a 90 calendar day period to make an additional investment in order to bring the value of your account to at least $500 before the Fund makes an involuntary redemption. This involuntary redemption will not charge any deferred sales charge, and may not apply to accounts of certain employer-sponsored retirement plans (not including IRAs), qualified state tuition plan (529 Plan) accounts, and select fee-based programs at your Financial Intermediary.

Participation in Fee-Based Programs

If you participate in certain fee-based programs offered by BlackRock or an affiliate of BlackRock, or by Financial Intermediaries that have agreements with the Distributor or in certain fee-based programs in which BlackRock participates, you may be able to buy Institutional Shares, including by exchanges from other share classes. Sales charges on the shares being exchanged may be reduced or waived under certain circumstances. You generally cannot transfer shares held through a fee-based program into another account. Instead, if you choose to leave the fee-based program, you may have to redeem your shares held through the program and purchase shares of another class, which may be subject to distribution and service fees. This may be a taxable event and you may pay any applicable sales charges or redemption fee. Please speak to your Financial Intermediary for information about specific policies and procedures applicable to your account.

Generally, upon termination of a fee-based program, the shares may be liquidated, or the shares can be held in an account. In certain instances, when a shareholder chooses to continue to hold the shares, whatever share class was held in the program can be held after termination. Shares that have been held for less than specified periods within the program may be subject to a fee upon redemption. Shareholders that held Investor A or Institutional Shares in the program may be eligible to purchase additional shares of the respective share class of the Fund, but may be subject to upfront sales charges with respect to Investor A Shares. Additional purchases of Institutional Shares are permitted only if you have an existing position at the time of purchase or are otherwise eligible to purchase Institutional Shares. Please speak to your Financial Intermediary for more information.

Certain Financial Intermediaries may, in connection with a change in account type (for example, due to leaving a fee-based program or upon termination of the fee-based program) or otherwise in accordance with the Financial Intermediary’s policies and procedures, exchange the share class held in the program for another share class of the same fund, provided that the exchanged shares are not subject to a sales charge and the shareholder meets the eligibility requirements of the new share class. Please speak to your Financial Intermediary for information about specific policies and procedures applicable to your account.

Details about the features of each fee-based program and the relevant charges, terms and conditions are included in the client agreement for each fee-based program and are available from your Financial Intermediary. Please speak to your Financial Intermediary for more information.

Short-Term Trading Policy

The Board of Directors of the Corporation (the “Board”) has determined that the interests of long-term shareholders and each Fund’s ability to manage its investments may be adversely affected when shares are repeatedly bought, sold or exchanged in response to short-term market fluctuations — also known as “market timing.” The Funds are not designed for market timing organizations or other entities using programmed or frequent purchases and sales or exchanges. The exchange privilege is not intended as a vehicle for short-term trading. Excessive purchase and sale or exchange activity may interfere with portfolio management, increase expenses and taxes and may have an adverse effect on the performance of a Fund and its returns to shareholders. For example, large flows of cash into and out of a Fund may require the management team to allocate a significant amount of assets to cash or other short-term investments or sell securities, rather than maintaining such assets in securities selected to achieve the Fund’s investment objective. Frequent trading may cause a Fund to sell securities at less favorable prices, and transaction costs, such as brokerage commissions, can reduce a Fund’s performance.

A fund’s investment in non-U.S. securities is subject to the risk that an investor may seek to take advantage of a delay between the change in value of a fund’s portfolio securities and the determination of the fund’s net asset value as a result of different closing times of U.S. and non-U.S. markets by buying or selling fund shares at a price that does not reflect their true value. A similar risk exists for funds that invest in securities of small capitalization companies, securities of issuers located in emerging markets or high yield securities (junk bonds) that are thinly traded and therefore may have actual values that differ from their market prices. This short-term arbitrage activity can reduce the return received by long-term shareholders. Each Fund will seek to eliminate these opportunities by using fair value pricing, as described in “Management of the Funds — Valuation of Fund Investments” below.

Each Fund discourages market timing and seeks to prevent frequent purchases and sales or exchanges of Fund shares that it determines may be detrimental to a Fund or long-term shareholders. The Board has approved the policies discussed below to seek to deter market timing activity. The Board has not adopted any specific numerical restrictions on purchases, sales and exchanges of Fund shares because certain legitimate strategies will not result in harm to a Fund or its shareholders.

If as a result of its own investigation, information provided by a Financial Intermediary or other third-party, or otherwise, a Fund believes, in its sole discretion, that your short-term trading is excessive or that you are engaging in market timing activity, it reserves the right to reject any specific purchase or exchange order. If a Fund rejects your purchase or exchange order, you will not be able to execute that transaction, and the Fund will not be responsible for any losses you therefore may suffer. For transactions placed directly with the Fund, the Fund may consider the trading history of accounts under common ownership or control for the purpose of enforcing these policies. Transactions placed through the same Financial Intermediary on an omnibus basis may be deemed part of a group for the purpose of this policy and may be rejected in whole or in part by a Fund. Certain accounts, such as omnibus accounts and accounts at Financial Intermediaries, however, include multiple investors and such accounts typically provide a Fund with net purchase or redemption and exchange requests on any given day where purchases, redemptions and exchanges of shares are netted against one another and the identity of individual purchasers, redeemers and exchangers whose orders are aggregated may not be known by a Fund. While the Funds monitor for market timing activity, the Funds may be unable to identify such activities because the netting effect in omnibus accounts often makes it more difficult to locate and eliminate market timers from the Funds. The Distributor has entered into agreements with respect to Financial Intermediaries that maintain omnibus accounts with the Funds pursuant to which such Financial Intermediaries undertake to cooperate with the Distributor in monitoring purchase, exchange and redemption orders by their customers in order to detect and prevent short-term or excessive trading in the Fund’s shares through such accounts. Identification of market timers may also be limited by operational systems and technical limitations. In the event that a Financial Intermediary is determined by a Fund to be engaged in market timing or other improper trading activity, the Distributor may terminate such Financial Intermediary’s agreement with the Distributor, suspend such Financial Intermediary’s trading privileges or take other appropriate actions.

There is no assurance that the methods described above will prevent market timing or other trading that may be deemed abusive.

The Funds may from time to time use other methods that they believe are appropriate to deter market timing or other trading activity that may be detrimental to the Fund or long-term shareholders.

Master/Feeder Structure

Russell 2000 Small-Cap Index Fund is a “feeder” fund that invests all of its assets in Master Small Cap Index Series of the Master LLC. Investors in Russell 2000 Small-Cap Index Fund will acquire an indirect interest in the Series.

Master Small Cap Index Series may accept investments from other feeder funds, and all the feeder funds of the Series bear the Series’ expenses in proportion to their assets. This structure may enable Russell 2000 Small-Cap Index Fund to reduce costs through economies of scale. A larger investment portfolio may also reduce certain transaction costs to the extent that contributions to and redemptions from the Series from different feeder funds may offset each other and produce a lower net cash flow.

However, each feeder fund can set its own transaction minimums, fund-specific expenses, and other conditions. This means that one feeder fund could offer access to the Series on more attractive terms, or could experience better performance, than another feeder fund. In addition, large purchases or redemptions by one feeder fund could negatively affect the performance of other feeder funds that invest in the Series. Information about other feeder funds, if any, is available by calling (800) 441-7762.

Whenever the Series holds a vote of its feeder funds, Russell 2000 Small-Cap Index Fund will pass the vote through to its own shareholders. Smaller feeder funds may be harmed by the actions of larger feeder funds. For example, a larger feeder fund could have more voting power than Russell 2000 Small-Cap Index Fund over the operations of the Series.

Russell 2000 Small-Cap Index Fund may withdraw from the Series at any time and may invest all of its assets in another pooled investment vehicle or retain an investment adviser to manage the Fund’s assets directly.

Management of the Funds

BlackRock

BlackRock is the investment manager for the Series in which Russell 2000 Small-Cap Index Fund invests and for MSCI EAFE International Index Fund. BlackRock manages the investments and business operations of the Series and MSCI EAFE International Index Fund, subject to the oversight of the Master LLC’s and Corporation’s Board of Directors, as applicable. While BlackRock is ultimately responsible for the management of the Series and MSCI EAFE International Index Fund, it is able to draw upon the trading, research and expertise of its asset management affiliates for portfolio decisions and management with respect to certain portfolio securities. BlackRock is an indirect, wholly-owned subsidiary of BlackRock, Inc.

BlackRock, a registered investment adviser, was organized in 1994 to perform advisory services for investment companies. BlackRock Fund Advisors (“BFA”), the sub-adviser to the Funds and an affiliate of BlackRock, is a registered investment adviser organized in 1984. BlackRock and its affiliates had approximately $10.472 trillion in investment company and other portfolio assets under management as of March 31, 2024.

The Master LLC and the Corporation have entered into separate agreements with BlackRock (each, a “Management Agreement”) pursuant to which BlackRock serves as manager to Master Small Cap Index Series and MSCI EAFE International Index Fund, as applicable. Pursuant to each Management Agreement, BlackRock is entitled to fees computed on a daily basis and payable monthly. Under each Management Agreement, the maximum annual fee rate payable by the Master LLC and the Corporation to BlackRock is 0.01% of the average daily net assets of each of Master Small Cap Index Series and MSCI EAFE International Index Fund, respectively. For the fiscal year ended December 31, 2023, BlackRock received management fees, net of any applicable waivers and/or reimbursements, at an annual rate as a percentage of average daily net assets of Master Small Cap Index Series of 0.01% and MSCI EAFE International Index Fund of 0.01%.

BlackRock has contractually agreed to waive the management fee with respect to any portion of each of the Series’ and MSCI EAFE International Index Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and ETFs managed by BlackRock or its affiliates that have a contractual management fee, through June 30, 2025. In addition, BlackRock has contractually agreed to waive its management fees by the amount of investment advisory fees the Series or MSCI EAFE International Index Fund, as applicable, pays to BlackRock indirectly through its investment in money market funds managed by BlackRock or its affiliates (the “affiliated money market fund waiver”), through June 30, 2025. The contractual agreements may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Master LLC or the Corporation, as applicable, or by a vote of a majority of the outstanding voting securities of the Series or MSCI EAFE International Index Fund, as applicable.

BlackRock has contractually agreed to cap net expenses (excluding (i) interest, taxes, dividends tied to short sales, brokerage commissions, and other expenditures which are capitalized in accordance with generally accepted accounting principles; (ii) Russell 2000 Small-Cap Index Fund’s pro rata share of the fees and expenses incurred indirectly by Russell 2000 Small-Cap Index Fund as a result of investing in other investment companies; (iii) other expenses attributable to, and incurred as a result of, Russell 2000 Small-Cap Index Fund’s investments; and (iv) extraordinary expenses (including litigation expenses) not incurred in the ordinary course of Russell 2000 Small-Cap Index Fund’s business, if any) of each share class of Russell 2000 Small-Cap Index Fund at the levels shown below and in Russell 2000 Small-Cap Index Fund’s fees and expense table in the “Fund Overview” section of this prospectus. Items (i), (ii), (iii) and (iv) in the preceding sentence are referred to in this prospectus as “Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses.” To achieve these expense caps, BlackRock has agreed to waive and/or reimburse fees or expenses if these operating expenses exceed a certain limit.

With respect to Master Small Cap Index Series, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses to the amount noted in the table below.

	Contractual Cap1 on Total Annual Fund Operating Expenses2 (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses)
Master Small Cap Index Series	0.07 %

The contractual cap is in effect through June 30, 2025. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Master LLC or by a vote of a majority of the outstanding voting securities of the Series.

As a percentage of average daily net assets.

BlackRock, as administrator for Russell 2000 Small-Cap Index Fund, has contractually agreed to waive and/or reimburse fees and/or expenses in order to limit the Total Annual Fund Operating Expenses to the amounts noted in the table below.

	Contractual Caps1 on Total Annual Fund Operating Expenses2 (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses)
Russell 2000 Small-Cap Index Fund
Investor A Shares	0.37 %
Institutional Shares	0.12 %

The contractual caps are in effect through June 30, 2025. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Corporation or by a vote of a majority of the outstanding voting securities of the Fund.

As a percentage of average daily net assets.

The amount of the contractual waivers and/or reimbursements of fees and expenses made pursuant to the contractual caps on net expenses will be reduced by the amount of the affiliated money market fund waiver.

BlackRock has entered into separate sub-advisory agreements (each, a “Sub-Advisory Agreement”) with BFA, with respect to Master Small Cap Index Series and MSCI EAFE International Index Fund, under which BlackRock pays BFA for services it provides for that portion of the Fund or Series, as applicable, for which BFA acts as sub-adviser under each Sub-Advisory Agreement a fee equal to a percentage of the management fee paid to BlackRock under the applicable Management Agreement.

A discussion of the basis for the approvals by the Board of Directors of the Corporation, with respect to Russell 2000 Small-Cap Index Fund, and the Board of Directors of the Master LLC, with respect to the Series, of the applicable Management Agreement and the applicable Sub-Advisory Agreement is included in the semi-annual shareholder report of Russell 2000 Small-Cap Index Fund for the period ended June 30, 2023. A discussion of the basis for the approval by the Board of Directors of the Corporation, with respect to MSCI EAFE International Index Fund, of the applicable Management Agreement and the applicable Sub-Advisory Agreement is included in the semi-annual shareholder report for MSCI EAFE International Index Fund for the period ended June 30, 2023.

From time to time, a manager, analyst, or other employee of BlackRock or its affiliates may express views regarding a particular asset class, company, security, industry, or market sector. The views expressed by any such person are the views of only that individual as of the time expressed and do not necessarily represent the views of BlackRock or any other person within the BlackRock organization. Any such views are subject to change at any time based upon market or other conditions and BlackRock disclaims any responsibility to update such views. These views may not be relied on as investment advice and, because investment decisions for the Funds are based on numerous factors, may not be relied on as an indication of trading intent on behalf of the Funds.

Administrative Services

With respect to Russell 2000 Small-Cap Index Fund, pursuant to an administration agreement between the Corporation, on behalf of the Fund, and BlackRock, BlackRock provides certain administrative services to the Fund.

With respect to MSCI EAFE International Index Fund, pursuant to the Management Agreement and an administration agreement between the Corporation, on behalf of the Fund, and BlackRock, BlackRock provides certain administrative services to the Fund.

Such administrative services include, among others:

◼

Supervising each Fund’s administrative operations;

◼

Overseeing the calculation of each Fund’s net asset value;

◼

Management reporting and treasury administration services;

◼

Financial reporting;

◼

Tax services; and

◼

Preparing proxy statements and shareholder reports.

With respect to MSCI EAFE International Index Fund, effective January 1, 2021, in addition to performing these services, BlackRock has agreed to bear all costs of operating the Fund, other than brokerage expenses, advisory fees, any 12b-1 fees, certain fees and expenses related to the Corporation’s directors who are not “interested persons” of the Corporation as defined in the Investment Company Act, and their counsel, auditing fees, litigation expenses, taxes and extraordinary expenses.

The contractual fee rate payable to BlackRock as a percentage of Russell 2000 Small-Cap Index Fund’s average daily net assets under the administration agreement is 0.04%. Effective January 1, 2021, the contractual fee rate payable to BlackRock as a percentage of MSCI EAFE International Index Fund’s average daily net assets attributable to Investor A and Institutional Shares under the administration agreement is 0.08%.

For the fiscal year ended December 31, 2023, the administration fee rate, net of any applicable waivers, for Russell 2000 Small-Cap Index Fund was 0.04%.

Portfolio Manager Information

Information regarding the portfolio managers of Master Small Cap Index Series and MSCI EAFE International Index Fund is set forth below. Further information regarding the portfolio managers, including other accounts managed, compensation, ownership of Fund shares, and possible conflicts of interest, is available in the Corporation’s SAI.

Portfolio Manager	Primary Role	Since	Title and Recent Biography
Paul Whitehead	Jointly and primarily responsible for the day-to-day management of the Series’ and the Fund’s portfolio, including setting the Series’ and the Fund’s overall investment strategy and overseeing the management of the Series and the Fund.	2022	Managing Director of BlackRock, Inc. since 2010; Director of BlackRock, Inc. from 2009 to 2010; Principal of Barclays Global Investors (“BGI”) from 2002 to 2009.
Jennifer Hsui, CFA	Jointly and primarily responsible for the day-to-day management of the Series’ and the Fund’s portfolio, including setting the Series’ and the Fund’s overall investment strategy and overseeing the management of the Series and the Fund.	2016	Managing Director of BlackRock, Inc. since 2011; Director of BlackRock, Inc. from 2009 to 2011; Principal of BGI from 2006 to 2009.

Conflicts of Interest

The investment activities of BlackRock and its affiliates (including BlackRock, Inc. and its subsidiaries (collectively, the “Affiliates”)), and their respective directors, officers or employees, in the management of, or their interest in, their own accounts and other accounts they manage, may present conflicts of interest that could disadvantage the Funds and their shareholders.

BlackRock and its Affiliates provide investment management services to other funds and discretionary managed accounts that may follow investment programs similar to that of the Funds. BlackRock and its Affiliates are involved worldwide with a broad spectrum of financial services and asset management activities and may engage in the ordinary course of business in activities in which their interests or the interests of their clients may conflict with those of the Funds. BlackRock or one or more Affiliates act or may act as an investor, research provider, investment manager, commodity pool operator, commodity trading advisor, financier, underwriter, adviser, trader, lender, index provider, agent and/or principal, and have other direct and indirect interests in securities, currencies, commodities, derivatives and other instruments in which the Funds may directly or indirectly invest. The Funds may invest in securities of, or engage in other transactions with, companies with which an Affiliate has significant debt or equity

investments or other interests. The Funds may also invest in issuances (such as structured notes) by entities for which an Affiliate provides and is compensated for cash management services relating to the proceeds from the sale of such issuances. The Funds also may invest in securities of, or engage in other transactions with, companies for which an Affiliate provides or may in the future provide research coverage. An Affiliate may have business relationships with, and purchase, or distribute or sell services or products from or to, distributors, consultants or others who recommend the Funds or who engage in transactions with or for the Funds, and may receive compensation for such services. BlackRock or one or more Affiliates may engage in proprietary trading and advise accounts and funds that have investment objectives similar to those of the Funds and/or that engage in and compete for transactions in the same types of securities, currencies and other instruments as the Funds. This may include transactions in securities issued by other open-end and closed-end investment companies (which may include investment companies that are affiliated with the Funds and BlackRock, to the extent permitted under the Investment Company Act). The trading activities of BlackRock and these Affiliates are carried out without reference to positions held directly or indirectly by the Funds and may result in BlackRock or an Affiliate having positions in certain securities that are senior or junior to, or have interests different from or adverse to, the securities that are owned by the Funds.

Neither BlackRock nor any Affiliate is under any obligation to share any investment opportunity, idea or strategy with the Funds. As a result, an Affiliate may compete with the Funds for appropriate investment opportunities. The results of a Fund’s investment activities, therefore, may differ from those of an Affiliate and of other accounts managed by BlackRock or an Affiliate, and it is possible that a Fund could sustain losses during periods in which one or more Affiliates and other accounts achieve profits on their trading for proprietary or other accounts. The opposite result is also possible.

In addition, the Funds may, from time to time, enter into transactions in which BlackRock or an Affiliate or their directors, officers or employees or other clients have an adverse interest. Furthermore, transactions undertaken by clients advised or managed by BlackRock or its Affiliates may adversely impact the Funds. Transactions by one or more clients or BlackRock or its Affiliates or their directors, officers or employees, may have the effect of diluting or otherwise disadvantaging the values, prices or investment strategies of the Funds. The Funds’ activities may be limited because of regulatory restrictions applicable to BlackRock or one or more Affiliates and/or their internal policies designed to comply with such restrictions.

Under a securities lending program approved by the Master LLC’s and Corporation’s Board of Directors, the Master LLC, on behalf of Master Small Cap Index Series, and the Corporation, on behalf of MSCI EAFE International Index Fund, has retained BlackRock Institutional Trust Company, N.A., an Affiliate of BlackRock, to serve as the securities lending agent for Master Small Cap Index Series and MSCI EAFE International Index Fund to the extent that Master Small Cap Index Series or MSCI EAFE International Index Fund participate in the securities lending program. For these services, the securities lending agent will receive a fee from Master Small Cap Index Series or MSCI EAFE International Index Fund, as applicable, based on the returns earned on Master Small Cap Index Series’ or MSCI EAFE International Index Fund’s lending activities, including investment of the cash received as collateral for the loaned securities. In addition, one or more Affiliates may be among the entities to which Master Small Cap Index Series or MSCI EAFE International Index Fund may lend its portfolio securities under the securities lending program.

The activities of BlackRock and its Affiliates and their respective directors, officers or employees, may give rise to other conflicts of interest that could disadvantage the Funds and their shareholders. BlackRock has adopted policies and procedures designed to address these potential conflicts of interest. See the SAI for further information.

Valuation of Fund Investments

When you buy shares, you pay the net asset value. This is the offering price. Shares are also redeemed at their net asset value, minus any applicable redemption fee. The net asset value used in determining your share price is the next one calculated after your purchase or redemption order is received. The net asset value of each class of shares normally is determined once daily Monday through Friday, generally as of the close of regular trading hours of the New York Stock Exchange (“NYSE”) (normally 4:00 p.m., Eastern time), on each day that the NYSE is open for trading, based on prices at the time of closing, provided that any Fund assets or liabilities denominated in currencies other than the U.S. dollar are translated into U.S. dollars at the prevailing market rates on the date of valuation as quoted by one or more data service providers. The net asset value of shares is calculated by dividing the value of the net assets of each class of shares (i.e., the value of its total assets less total liabilities) by the total number of outstanding shares of the class, generally rounded to the nearest cent.

Generally, Institutional Shares will have the highest net asset value because that class has the lowest expenses. Also, dividends paid on Investor A and Institutional Shares will generally be higher because Investor A and Institutional Shares have lower expenses.

The value of the securities and other assets and liabilities held by a Fund are determined pursuant to BlackRock’s valuation policies and procedures. BlackRock has been designated by the Board as the valuation designee for the Fund pursuant to Rule 2a-5 under the Investment Company Act.

Equity securities and other equity instruments for which market quotations are readily available are valued at market value, which is generally determined using the last reported official closing price or, if a reported closing price is not available, the last traded price on the exchange or market on which the security or instrument is primarily traded at the time of valuation. Shares of underlying open-end funds (including money market funds) are valued at net asset value. Shares of underlying exchange-traded closed-end funds or other ETFs are valued at their most recent closing price.

Each Fund values fixed-income portfolio securities using last available bid prices or current market quotations provided by dealers or prices (including evaluated prices) supplied by the Fund’s approved independent third-party pricing services, each in accordance with BlackRock’s valuation policies and procedures. Pricing services may use matrix pricing or valuation models that utilize certain inputs and assumptions to derive values. Pricing services generally value fixed-income securities assuming orderly transactions of an institutional round lot size, but a Fund may hold or transact in such securities in smaller odd lot sizes. Odd lots may trade at lower prices than institutional round lots. An amortized cost method of valuation may be used with respect to debt obligations with 60 days or less remaining to maturity unless BlackRock determines in good faith that such method does not represent fair value.

Generally, trading in non-U.S. securities, U.S. government securities, money market instruments and certain fixed-income securities is substantially completed each day at various times prior to the close of business on the NYSE. The values of such securities used in computing the net asset value of a Fund’s shares are determined as of such times.

When market quotations are not readily available or are believed by BlackRock to be unreliable, BlackRock will fair value a Fund’s investments in accordance with its policies and procedures. BlackRock may conclude that a market quotation is not readily available or is unreliable if a security or other asset or liability does not have a price source due to its lack of trading or other reasons, if a market quotation differs significantly from recent price quotations or otherwise no longer appears to reflect fair value, where the security or other asset or liability is thinly traded, when there is a significant event subsequent to the most recent market quotation, or if the trading market on which a security is listed is suspended or closed and no appropriate alternative trading market is available. A “significant event” is deemed to occur if BlackRock determines, in its reasonable business judgment prior to or at the time of pricing a Fund’s assets or liabilities, that the event is likely to cause a material change to the closing market price of one or more assets held by, or liabilities of, the Fund.

For certain foreign assets, a third-party vendor supplies evaluated, systematic fair value pricing based upon the movement of a proprietary multi-factor model after the relevant foreign markets have closed. This systematic fair value pricing methodology is designed to correlate the prices of foreign assets following the close of the local markets to the price that might have prevailed as of a Fund’s pricing time.

Fair value represents a good faith approximation of the value of an asset or liability. The fair value of an asset or liability held by a Fund is the amount the Fund might reasonably expect to receive from the current sale of that asset or the cost to extinguish that liability in an arm’s-length transaction. Valuing a Fund’s investments using fair value pricing will result in prices that may differ from current market valuations and that may not be the prices at which those investments could have been sold during the period in which the particular fair values were used. Use of fair value prices and certain current market valuations could result in a difference between the prices used to calculate a Fund’s net asset value and the prices used by the applicable index, which, in turn, could result in a difference between a Fund’s performance and the performance of the applicable index.

Each Fund may accept orders from certain authorized Financial Intermediaries or their designees. Each Fund will be deemed to receive an order when accepted by the Financial Intermediary or designee, and the order will receive the net asset value next computed by the Fund after such acceptance. If the payment for a purchase order is not made by a designated later time, the order will be canceled and the Financial Intermediary could be held liable for any losses.

Dividends, Distributions and Taxes

BUYING A DIVIDEND

Unless your investment is in a tax-deferred account, you may want to avoid buying shares shortly before each Fund pays a dividend. The reason? If you buy shares when a Fund has declared but not yet distributed ordinary income or capital gains, you will pay the full price for the shares and then receive a portion of the price back in the form of a taxable dividend. Before investing you may want to consult your tax adviser.

Each Fund will distribute net investment income, if any, and net realized capital gains, if any, at least annually. Each Fund may also pay a special distribution at the end of the calendar year to comply with federal tax requirements. Dividends may be reinvested automatically in shares of each Fund at net asset value or may be taken in cash. If you would like to receive dividends in cash, contact your Financial Intermediary or the applicable Fund. Although this cannot be predicted with any certainty, each Fund anticipates that a significant amount of its dividends, if any, will consist of capital gains. Capital gains may be taxable to you at different rates depending on how long the Fund held the assets sold.

You will pay tax on dividends from a Fund whether you receive them in cash or additional shares. If you redeem Fund shares or exchange them for shares of another fund, you generally will be treated as having sold your shares and any gain on the transaction may be subject to tax. Fund distributions derived from qualified dividend income, which consists of dividends received from U.S. corporations and qualifying foreign corporations, and from long-term capital gains are eligible for taxation at a maximum rate of 15% or 20% for individuals, depending on whether their income exceeds certain threshold amounts, which are adjusted annually for inflation.

A 3.8% Medicare tax is imposed on the net investment income (which includes, but is not limited to, interest, dividends and net gain from investments) of U.S. individuals with income exceeding $200,000, or $250,000 if married filing jointly, and of trusts and estates.

Your dividends and redemption proceeds will be subject to backup withholding tax if you have not provided a taxpayer identification number or social security number or the number you have provided is incorrect.

If you are neither a tax resident nor a citizen of the United States or if you are a foreign entity (other than a pass-through entity to the extent owned by U.S. persons), a Fund’s ordinary income dividends will generally be subject to a 30% U.S. withholding tax, unless a lower treaty rate applies. However, certain distributions reported by a Fund as capital gain dividends, interest-related dividends or short-term capital gain dividends and paid to a foreign shareholder may be eligible for an exemption from U.S. withholding tax.

Separately, a 30% withholding tax is currently imposed on U.S.-source dividends, interest and other income items paid to (i) certain foreign financial institutions and investment funds, and (ii) certain other foreign entities. To avoid withholding, foreign financial institutions and investment funds will generally either need to (a) collect and report to the IRS detailed information identifying their U.S. accounts and U.S. account holders, comply with due diligence procedures for identifying U.S. accounts and withhold tax on certain payments made to noncomplying foreign entities and account holders or (b) if an intergovernmental agreement is entered into and implementing legislation is adopted, comply with the agreement and legislation. Other foreign entities will generally either need to provide detailed information identifying each substantial U.S. owner or certify there are no such owners.

With respect to MSCI EAFE International Index Fund, dividends and interest received by the Fund and capital gains recognized by the Fund may give rise to withholding and other taxes imposed by foreign countries. Tax conventions between certain countries and the United States may reduce or eliminate such taxes. You may be able to claim a credit or take a deduction for foreign taxes paid by the Fund if certain requirements are met.

This section summarizes some of the consequences under current federal tax law of an investment in a Fund. It is not a substitute for individualized tax advice. Consult your tax adviser about the potential tax consequences of an investment in a Fund under all applicable tax laws.

Financial Highlights

The financial highlights tables are intended to help investors understand each Fund’s financial performance of the shares of each Fund for the past five years. Certain information reflects the financial results for a single share of the Fund. The total returns in the tables represent the rate of return that an investor would have earned (or lost) on an investment in the shares of the Fund, assuming reinvestment of all dividends and/or distributions. The information has been audited by Deloitte & Touche LLP, whose report, along with each Fund’s financial statements, are included in the respective Fund’s annual report. You may obtain copies of the annual report, at no cost, by calling (800) 441-7762 (toll-free) from 8:00 a.m. to 6:00 p.m. (Eastern time) on any business day.

	iShares Russell 2000 Small-Cap Index Fund
	Institutional
	Year Ended 12/31/23	Year Ended 12/31/22	Year Ended 12/31/21	Year Ended 12/31/20	Year Ended 12/31/19
(For a share outstanding throughout each period)	Year Ended 12/31/23	Year Ended 12/31/22	Year Ended 12/31/21	Year Ended 12/31/20	Year Ended 12/31/19
Net asset value, beginning of year	$20.17	$25.76	$24.19	$20.46	$16.87
Net investment income(a)	0.33	0.27	0.25	0.23	0.27
Net realized and unrealized gain (loss)(b)	3.07	(5.52 )	3.28	3.84	4.02
Net increase (decrease) from investment operations	3.40	(5.25 )	3.53	4.07	4.29
Distributions(c)
From net investment income	(0.35 )	(0.28 )	(0.29 )	(0.25 )	(0.28 )
From net realized gain	(0.32 )	(0.06 )	(1.67 )	(0.09 )	(0.42 )
Total distributions	(0.67 )	(0.34 )	(1.96 )	(0.34 )	(0.70 )
Net asset value, end of year	$22.90	$20.17	$25.76	$24.19	$20.46
Total Return(d)
Based on net asset value	16.90 %	(20.39 )%	14.73 %	19.97 %	25.50 %
Ratios to Average Net Assets(e)(f)(g)
Total expenses	0.13 %	0.13 %	0.12 %	0.16 %	0.16 %
Total expenses after fees waived and/or reimbursed	0.12 %	0.12 %	0.12 %	0.12 %	0.12 %
Net investment income	1.55 %	1.26 %	0.93 %	1.22 %	1.38 %
Supplemental Data
Net assets, end of year (000)	$400,743	$390,670	$479,451	$331,429	$227,381
Portfolio turnover rate of the Series	29 %	38 %	31 %	27 %	20 %

(a)	Based on average Common Shares outstanding.
(b)	The amounts reported for a share outstanding may not accord with the change in aggregate gains and losses in securities for the fiscal period due to the timing of capital share transactions in relation to the fluctuating market values of the Fund’s underlying securities.
(c)	Distributions for annual periods determined in accordance with U.S. federal income tax regulations.
(d)	Where applicable, assumes the reinvestment of distributions.
(e)	Includes the Fund’s share of the Master Portfolio’s allocated net expenses and/or net investment income.
(f)	Includes the Fund’s share of the Series’ allocated fees waived of less than 0.01%.
(g)	Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.

Financial Highlights (continued)

	iShares Russell 2000 Small-Cap Index Fund
	Investor A
	Year Ended 12/31/23	Year Ended 12/31/22	Year Ended 12/31/21	Year Ended 12/31/20	Year Ended 12/31/19
(For a share outstanding throughout each period)	Year Ended 12/31/23	Year Ended 12/31/22	Year Ended 12/31/21	Year Ended 12/31/20	Year Ended 12/31/19
Net asset value, beginning of year	$20.20	$25.79	$24.22	$20.49	$16.89
Net investment income(a)	0.27	0.22	0.18	0.17	0.22
Net realized and unrealized gain (loss)(b)	3.08	(5.52 )	3.28	3.85	4.03
Net increase (decrease) from investment operations	3.35	(5.30 )	3.46	4.02	4.25
Distributions(c)
From net investment income	(0.30 )	(0.23 )	(0.22 )	(0.20 )	(0.23 )
From net realized gain	(0.32 )	(0.06 )	(1.67 )	(0.09 )	(0.42 )
Total distributions	(0.62 )	(0.29 )	(1.89 )	(0.29 )	(0.65 )
Net asset value, end of year	$22.93	$20.20	$25.79	$24.22	$20.49
Total Return(d)
Based on net asset value	16.60 %	(20.57 )%	14.38 %	19.66 %	25.20 %
Ratios to Average Net Assets(e)(f)(g)
Total expenses	0.42 %	0.40 %	0.40 %	0.41 %	0.42 %
Total expenses after fees waived and/or reimbursed	0.37 %	0.37 %	0.37 %	0.37 %	0.37 %
Net investment income	1.29 %	1.01 %	0.66 %	0.93 %	1.14 %
Supplemental Data
Net assets, end of year (000)	$206,977	$194,549	$243,110	$257,905	$273,413
Portfolio turnover rate of the Series	29 %	38 %	31 %	27 %	20 %

(a)	Based on average Common Shares outstanding.
(b)	The amounts reported for a share outstanding may not accord with the change in aggregate gains and losses in securities for the fiscal period due to the timing of capital share transactions in relation to the fluctuating market values of the Fund’s underlying securities.
(c)	Distributions for annual periods determined in accordance with U.S. federal income tax regulations.
(d)	Where applicable, assumes the reinvestment of distributions.
(e)	Includes the Fund’s share of the Master Portfolio’s allocated net expenses and/or net investment income.
(f)	Includes the Fund’s share of the Series’ allocated fees waived of less than 0.01%.
(g)	Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.

Financial Highlights (continued)

	iShares MSCI EAFE International Index Fund
	Institutional
	Year Ended 12/31/23	Year Ended 12/31/22	Year Ended 12/31/21	Year Ended 12/31/20	Year Ended 12/31/19
(For a share outstanding throughout each period)	Year Ended 12/31/23	Year Ended 12/31/22	Year Ended 12/31/21	Year Ended 12/31/20	Year Ended 12/31/19
Net asset value, beginning of year	$13.25	$15.85	$14.68	$13.86	$11.76
Net investment income(a)	0.43	0.41	0.41	0.30	0.42
Net realized and unrealized gain (loss)(b)	1.99	(2.64 )	1.24	0.81	2.14
Net increase (decrease) from investment operations	2.42	(2.23 )	1.65	1.11	2.56
Distributions from net investment income(c)	(0.48 )	(0.37 )	(0.48 )	(0.29 )	(0.46 )
Net asset value, end of year	$15.19	$13.25	$15.85	$14.68	$13.86
Total Return(d)
Based on net asset value	18.33 %	(14.18 )%	11.28 %	8.03 %	21.80 %
Ratios to Average Net Assets(e)
Total expenses	0.10 %	0.09 %	0.09 %	0.09 %	0.08 %
Total expenses after fees waived and/or reimbursed	0.10 %	0.09 %	0.09 %	0.09 %	0.08 %
Net investment income	2.97 %	3.06 %	2.57 %	2.35 %	3.23 %
Supplemental Data
Net assets, end of year (000)	$1,126,850	$1,036,641	$1,058,978	$1,004,855	$876,551
Portfolio turnover rate	17 %	4 %	3 %	8 %	4 %

(a)	Based on average shares outstanding.
(b)	The amounts reported for a share outstanding may not accord with the change in aggregate gains and losses in securities for the fiscal period due to the timing of capital share transactions in relation to the fluctuating market values of the Fund’s underlying securities.
(c)	Distributions for annual periods determined in accordance with U.S. federal income tax regulations.
(d)	Where applicable, assumes the reinvestment of distributions.
(e)	Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.

Financial Highlights (concluded)

	iShares MSCI EAFE International Index Fund
	Investor A
	Year Ended 12/31/23	Year Ended 12/31/22	Year Ended 12/31/21	Year Ended 12/31/20	Year Ended 12/31/19
(For a share outstanding throughout each period)	Year Ended 12/31/23	Year Ended 12/31/22	Year Ended 12/31/21	Year Ended 12/31/20	Year Ended 12/31/19
Net asset value, beginning of year	$13.16	$15.74	$14.58	$13.78	$11.69
Net investment income(a)	0.39	0.38	0.36	0.27	0.39
Net realized and unrealized gain (loss)(b)	1.97	(2.63 )	1.24	0.78	2.12
Net increase (decrease) from investment operations	2.36	(2.25 )	1.60	1.05	2.51
Distributions from net investment income(c)	(0.44 )	(0.33 )	(0.44 )	(0.25 )	(0.42 )
Net asset value, end of year	$15.08	$13.16	$15.74	$14.58	$13.78
Total Return(d)
Based on net asset value	18.02 %	(14.36 )%	11.01 %	7.68 %	21.53 %
Ratios to Average Net Assets(e)
Total expenses	0.35 %	0.34 %	0.34 %	0.35 %	0.35 %
Total expenses after fees waived and/or reimbursed	0.35 %	0.34 %	0.34 %	0.35 %	0.35 %
Net investment income	2.75 %	2.85 %	2.31 %	2.11 %	3.00 %
Supplemental Data
Net assets, end of year (000)	$385,832	$348,314	$385,287	$351,999	$340,750
Portfolio turnover rate	17 %	4 %	3 %	8 %	4 %

(a)	Based on average shares outstanding.
(b)	The amounts reported for a share outstanding may not accord with the change in aggregate gains and losses in securities for the fiscal period due to the timing of capital share transactions in relation to the fluctuating market values of the Fund’s underlying securities.
(c)	Distributions for annual periods determined in accordance with U.S. federal income tax regulations.
(d)	Where applicable, assumes the reinvestment of distributions.
(e)	Excludes fees and expenses incurred indirectly as a result of investments in underlying funds.

General Information

Shareholder Documents

Electronic Access to Annual Reports, Semi-Annual Reports and Prospectuses

Electronic copies of most financial reports and prospectuses are available on BlackRock’s website. Shareholders can sign up for e-mail notifications of annual and semi-annual reports and prospectuses by enrolling in the Funds’ electronic delivery program. To enroll:

Shareholders Who Hold Accounts with Investment Advisers, Banks or Brokerages: Please contact your Financial Intermediary. Please note that not all investment advisers, banks or brokerages may offer this service.

Shareholders Who Hold Accounts Directly With BlackRock:

◼

Access the BlackRock website at http://www.blackrock.com/edelivery; and

◼

Log into your account.

Delivery of Shareholder Documents

The Funds deliver only one copy of shareholder documents, including prospectuses, shareholder reports and proxy statements, to shareholders with multiple accounts at the same address. This practice is known as “householding” and is intended to eliminate duplicate mailings and reduce expenses. Mailings of your shareholder documents may be householded indefinitely unless you instruct us otherwise. If you do not want the mailing of these documents to be combined with those for other members of your household, please contact your Fund at (800) 441-7762.

Certain Fund Policies

Anti-Money Laundering Requirements

Each Fund is subject to the USA PATRIOT Act (the “Patriot Act”). The Patriot Act is intended to prevent the use of the U.S. financial system in furtherance of money laundering, terrorism or other illicit activities. Pursuant to requirements under the Patriot Act, each Fund is required to obtain sufficient information from shareholders to enable it to form a reasonable belief that it knows the true identity of its shareholders. This information will be used to verify the identity of investors or, in some cases, the status of Financial Intermediaries. Such information may be verified using third-party sources. This information will be used only for compliance with the Patriot Act or other applicable laws, regulations and rules in connection with money laundering, terrorism or economic sanctions.

The Fund reserves the right to reject purchase orders from persons who have not submitted information sufficient to allow the Fund to verify their identity. The Fund also reserves the right to redeem any amounts in the Fund from persons whose identity it is unable to verify on a timely basis. It is each Fund’s policy to cooperate fully with appropriate regulators in any investigations conducted with respect to potential money laundering, terrorism or other illicit activities.

BlackRock Privacy Principles

BlackRock is committed to maintaining the privacy of its current and former fund investors and individual clients (collectively, “Clients”) and to safeguarding their non-public personal information. The following information is provided to help you understand what personal information BlackRock collects, how we protect that information and why in certain cases we share such information with select parties.

If you are located in a jurisdiction where specific laws, rules or regulations require BlackRock to provide you with additional or different privacy-related rights beyond what is set forth below, then BlackRock will comply with those specific laws, rules or regulations.

BlackRock obtains or verifies personal non-public information from and about you from different sources, including the following: (i) information we receive from you or, if applicable, your Financial Intermediary, on applications, forms or other documents; (ii) information about your transactions with us, our affiliates or others; (iii) information we receive from a consumer reporting agency; and (iv) from visits to our website.

BlackRock does not sell or disclose to non-affiliated third parties any non-public personal information about its Clients, except as permitted by law, or as is necessary to respond to regulatory requests or to service Client accounts. These non-affiliated third parties are required to protect the confidentiality and security of this information and to use it only for its intended purpose.

We may share information with our affiliates to service your account or to provide you with information about other BlackRock products or services that may be of interest to you. In addition, BlackRock restricts access to non-public personal information about its Clients to those BlackRock employees with a legitimate business need for the information. BlackRock maintains physical, electronic and procedural safeguards that are designed to protect the non-public personal information of its Clients, including procedures relating to the proper storage and disposal of such information.

Statement of Additional Information

If you would like further information about each Fund, including how each Fund invests, please see the SAI.

For a discussion of each Fund’s policies and procedures regarding the selective disclosure of its portfolio holdings, please see the SAI. The Funds make their top ten holdings available on a monthly basis at www.blackrock.com generally within 5 business days after the end of the month to which the information applies.

Glossary

This glossary contains an explanation of some of the common terms used in this prospectus. For additional information about the Funds, please see the SAI.

Acquired Fund Fees and Expenses — a Fund’s pro rata share of the fees and expenses incurred indirectly by the Fund as a result of investing in other investment companies.

Administration Fee — a fee paid to the Administrator for providing administrative services to Russell 2000 Small-Cap Index Fund and MSCI EAFE International Index Fund.

Annual Fund Operating Expenses — expenses that cover the costs of operating a Fund.

Distribution Fees — fees used to support a Fund’s marketing and distribution efforts, such as compensating Financial Intermediaries, advertising and promotion.

Management Fee — a fee paid to BlackRock for managing the Series or MSCI EAFE International Index Fund, as applicable.

Market-Weighted Index — an index in which the weighting of each security is based on its market capitalization. In a market-weighted index, changes in the price of a company with a large capitalization affect the level of the index more than changes in the price of a company with smaller market capitalization.

MSCI EAFE Index (Europe, Australasia, Far East) — an equity index which captures large- and mid-cap representation across 21 developed markets countries around the world, excluding the United States and Canada. With 783 constituents, the index covers approximately 85% of the free float-adjusted market capitalization in each country.

Other Expenses — include accounting, administration, transfer agency, custody, professional and registration fees.

Russell 2000® Index — an index that measures the performance of the small-cap segment of the US equity universe. The Russell 2000® Index is a subset of the Russell 3000® Index representing approximately 7% of the total market capitalization of that index. It includes approximately 2,000 of the smallest securities based on a combination of their market cap and current index membership.

Service Fees — fees used to compensate Financial Intermediaries for certain shareholder servicing activities.

For More Information

Funds and Service Providers

FUNDS

BlackRock Index Funds, Inc.
iShares Russell 2000 Small-Cap Index Fund
iShares MSCI EAFE International Index Fund
100 Bellevue Parkway
Wilmington, Delaware 19809

Written Correspondence:
P.O. Box 534429
Pittsburgh, Pennsylvania 15253-4429

Overnight Mail:
Attention: 534429
500 Ross Street 154-0520
Pittsburgh, Pennsylvania 15262

(800) 441-7762

MANAGER

BlackRock Advisors, LLC
100 Bellevue Parkway
Wilmington, Delaware 19809

ADMINISTRATOR

BlackRock Advisors, LLC
100 Bellevue Parkway
Wilmington, Delaware 19809

SUB-ADVISER

BlackRock Fund Advisors
400 Howard Street
San Francisco, California 94105

TRANSFER AGENT

BNY Mellon Investment Servicing (US) Inc.
301 Bellevue Parkway
Wilmington, Delaware 19809

INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Deloitte & Touche LLP
200 Berkeley Street
Boston, Massachusetts 02116

ACCOUNTING SERVICES PROVIDER

State Street Bank and Trust Company
One Congress Street, Suite 1
Boston, Massachusetts 02114-2016

DISTRIBUTOR

BlackRock Investments, LLC
50 Hudson Yards
New York, New York 10001

CUSTODIAN

State Street Bank and Trust Company
One Congress Street, Suite 1
Boston, Massachusetts 02114-2016

COUNSEL

Sidley Austin LLP
787 Seventh Avenue
New York, New York 10019

Additional Information

For more information:
This prospectus contains important information you should know before investing, including information about risks. Please read it before you invest and keep it for future reference. More information about the Funds is available at no charge upon request. This information includes:

Annual/Semi-Annual Reports
These reports contain additional information about each Fund’s investments. The annual report describes each Fund’s performance, lists portfolio holdings, and discusses recent market conditions, economic trends and Fund investment strategies that significantly affected each Fund’s performance for the last fiscal year.

Statement of Additional Information
A Statement of Additional Information (“SAI”), dated April 29, 2024, has been filed with the Securities and Exchange Commission (the “SEC”). The SAI, which includes additional information about each Fund, may be obtained free of charge, along with each Fund’s annual and semi-annual reports, by calling (800) 441-7762. The SAI, as amended and/or supplemented from time to time, is incorporated by reference into this prospectus.

BlackRock Investor Services
Representatives are available to discuss account balance information, mutual fund prospectuses, literature, programs and services available. Hours: 8:00 a.m. to 6:00 p.m. (Eastern time), on any business day. Call: (800) 441-7762.

Purchases and Redemptions
Call your Financial Intermediary or BlackRock Investor Services at (800) 441-7762.

World Wide Web
General Fund information and specific Fund performance, including the SAI and annual/semi-annual reports, can be accessed free of charge at www.blackrock.com/prospectus. Mutual fund prospectuses and literature can also be requested via this website.

Written Correspondence
BlackRock Index Funds, Inc.
P.O. Box 534429
Pittsburgh, Pennsylvania 15253-4429

Overnight Mail
BlackRock Index Funds, Inc.
Attention: 534429
500 Ross Street 154-0520
Pittsburgh, Pennsylvania 15262

Internal Wholesalers/Broker Dealer Support
Available on any business day to support investment professionals. Call: (800) 882-0052.

Portfolio Characteristics and Holdings
A description of each Fund’s policies and procedures related to disclosure of portfolio characteristics and holdings is available in the SAI.

For information about portfolio holdings and characteristics, BlackRock fund shareholders and prospective investors may call (800) 882-0052.

Securities and Exchange Commission
You may also view and copy public information about each Fund, including the SAI, by visiting the EDGAR database on the SEC’s website (http://www.sec.gov). Copies of this information can be obtained, for a duplicating fee, by electronic request at the following e-mail address: [email protected].

You should rely only on the information contained in this prospectus. No one is authorized to provide you with information that is different from information contained in this prospectus.

The SEC has not approved or disapproved these securities or passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

INVESTMENT COMPANY ACT FILE # 811-7899

PRO-MSCIRUS2-INV-0424

Fund Overview	Key facts and details about the Funds listed in this prospectus, including investment objectives, principal investment strategies, principal risk factors, fee and expense information and historical performance information
	Key Facts About iShares Russell 2000 Small-Cap Index Fund	3
	Key Facts About iShares MSCI EAFE International Index Fund	9

Details About the Funds	Information about how each Fund invests, including investment objectives, investment processes, principal strategies and risk factors
	How Each Fund Invests	15
	Investment Risks	18

Account Information	Information about account services, sales charges and waivers, shareholder transactions, and distribution and other payments
	How to Choose the Share Class that Best Suits Your Needs	28
	Details About the Share Classes	31
	Distribution and Shareholder Servicing Payments	32
	How to Buy, Sell, Exchange and Transfer Shares	33
	Account Services and Privileges	38
	Funds’ Rights	39
	Participation in Fee-Based Programs	40
	Short-Term Trading Policy	40
	Master/Feeder Structure	41

Management of the Funds	Information about BlackRock and the Portfolio Managers
	BlackRock	42
	Administrative Services	43
	Portfolio Manager Information	44
	Conflicts of Interest	44
	Valuation of Fund Investments	45
	Dividends, Distributions and Taxes	47

For More Information	Funds and Service Providers	Inside Back Cover
	Additional Information	Back Cover