485BPOS

PIMCO Equity Series

Prospectus

November 1, 2021

Equity Exchange-Traded Funds

	TICKER	EXCHANGE
SMART BETA
PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF	MFEM	NYSE Arca
PIMCO RAFI Dynamic Multi-Factor International Equity ETF	MFDX	NYSE Arca
PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF	MFUS	NYSE Arca
PIMCO RAFI ESG U.S. ETF	RAFE	NYSE Arca

Neither the U.S. Securities and Exchange Commission nor the U.S. Commodity Futures Trading Commission has approved or disapproved these securities, or determined if this prospectus is truthfuI or compIete. Any representation to the contrary is a criminaI offense.

As permitted by reguIations adopted by the Securities and Exchange Commission, paper copies of the Fund’s annual and semi-annual shareholder reports will no longer be sent by mail from the financial intermediary, such as a broker-dealer or bank, which offers the Fund unless you specifically request paper copies of the reports from the financial intermediary. Instead, the shareholder reports will be made available on a website, and the financial intermediary will notify you by mail each time a report is posted and provide you with a website link to access the report. Instructions for requesting paper copies will be provided by your financial intermediary.

If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the financial intermediary electronically by following the instructions provided by the financial intermediary.

You may elect to receive all future reports in paper free of charge from the financial intermediary. You should contact the financial intermediary if you wish to continue receiving paper copies of your shareholder reports. Your election to receive reports in paper will apply to all funds held in your account at the financial intermediary.

Table of Contents

	Page
Fund Summaries	1
PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF	1
PIMCO RAFI Dynamic Multi-Factor International Equity ETF	5
PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF	9
PIMCO RAFI ESG U.S. ETF	13
Summary of Other Important Information Regarding Fund Shares	17
Description of Principal Risks	18
Disclosure of Portfolio Holdings	24
Management of the Funds	25
Buying and Selling Shares	27
How Net Asset Value Is Determined	28
Fund Distributions	30
Tax Consequences	30
Characteristics and Risks of Securities and Investment Techniques	31
Underlying Indexes	41
Disclaimers	42
Financial Highlights	44

PIMCO RAFI Dynamic Multi-Factor

Emerging Markets Equity ETF

Investment Objective

The Fund seeks to track the investment results of the RAFI Dynamic Multi-Factor Emerging Markets Index.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and example below.

Shareholder Fees (fees paid directly from your investment):

N/A

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

Management Fees	0.49%
Other Expenses(1)	0.02%
Acquired Fund Fees and Expenses	0.01%
Total Annual Fund Operating Expenses(2)	0.52%
Fee Waiver and/or Expense Reimbursement(3)	(0.01%)
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	0.51%

“Other Expenses” include expenses incurred by the Fund in the normal course of its operations together with recoupment of management fees previously waived or reimbursed to the Fund. Such expenses are borne by the Fund separately from the management fees paid to Pacific Investment Management Company LLC (“PIMCO”).

Total Annual Fund Operating Expenses do not match the Ratio of Expenses to Average Net Assets Excluding Waivers of the Fund, as set forth in the Financial Highlights table of the Fund’s prospectus, because the Ratio of Expenses to Average Net Assets Excluding Waivers reflects the operating expenses of the Fund and does not include Acquired Fund Fees and Expenses.

PIMCO has contractually agreed, through October 31, 2022, to waive a portion of the Fund’s management fees, or reimburse the Fund, to the extent that the Fund’s organizational expenses, pro rata share of expenses related to obtaining or maintaining a Legal Entity Identifier and pro rata share of Trustee fees exceed 0.0049% (the “Expense Limit”) (calculated as a percentage of average daily net assets). This Expense Limitation Agreement will automatically renew for one-year terms unless PIMCO provides written notice to PIMCO Equity Series at least 30 days prior to the end of the then current term. In any month in which the investment management agreement is in effect, PIMCO is entitled to reimbursement by the Fund of any portion of the management fee waived or reimbursed as set forth above (the “Reimbursement Amount”) during the previous thirty-six months from the time of the waiver, provided that such amount paid to PIMCO will not: 1) together with any organizational expenses, pro rata share of expenses related to obtaining or maintaining a Legal Entity Identifier and pro rata Trustee fees, exceed, for such month, the Expense Limit (or the amount of the expense limit in place at the time the amount being recouped was originally waived if lower than the Expense Limit); 2) exceed the total Reimbursement Amount; or 3) include any amounts previously reimbursed to PIMCO.

Example.

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
$52	$166	$290	$652

Portfolio Turnover

The Fund pays transaction costs when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in the Annual Fund Operating Expenses or in the Example tables, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 58% of the average value of its portfolio.

Principal Investment Strategies

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities (“Component Securities”) of the RAFI Dynamic Multi-Factor Emerging Markets Index (the “Underlying Index”). The Fund may invest the remainder of its assets in cash, securities and instruments that are not Component Securities, but which the Fund’s sub-adviser, Parametric Portfolio Associates LLC (“Sub-Adviser”), believes will help the Fund track its Underlying Index. The Underlying Index is designed to provide long-only exposure to multiple equity factors that seek to produce attractive long-term returns, and which may lower risk compared to less diversified strategies.

The Underlying Index is constructed by RAFI Indices, LLC (the “Index Provider”) using a rules-based approach to construct factor portfolios within the Underlying Index. The universe for the Underlying Index construction process starts with all common equity securities traded on primary exchanges, and preferred shares in countries where preferred shares are economically equivalent to common, which meet and pass minimum liquidity and investability (capacity) requirements, issued by companies that are assigned to countries classified by the Index Provider as emerging markets. As of September 30, 2021, there are 25 emerging market countries eligible for inclusion. The Index Provider assigns companies to countries and promulgates that assignment to securities. Eligible securities are then determined by selecting companies based on fundamental weight, calculated using four accounting measures from company financial statements: (i) de-levered sales, calculated as company sales averaged over the past five years multiplied by the ratio of average equity to average assets; (ii) cash flow, taken as the company operating cash flow averaged over the past five years; (iii) dividend plus buybacks, calculated using the average dividends paid and share buybacks over the past five years; and (iv) book value, taken as the most recent company book value. At each annual reconstitution, companies that rank in the top 86% of cumulative fundamental weight are eligible for selection in the Underlying Index.

PIMCO Equity Series | Prospectus 1

PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF

The Underlying Index consists of “factor portfolios,” each of which emphasizes one of the following factors: value, low volatility, quality and momentum. The value factor emphasizes companies with high ratio of company fundamental weight to its market capitalization weight. The low volatility factor emphasizes companies with low risk measure calculated as the variance of a company’s daily excess return over five years explained by global, local country groups, and global industry excess returns. The quality factor emphasizes companies that are high in profitability and low in investment spending. The momentum factor emphasizes stocks with high momentum. For the value, low volatility and quality “factor portfolios”, eligible securities are ranked by their factor score and the top 25% of companies by fundamental weight are selected for inclusion within that “factor portfolio”. For the momentum “factor portfolio”, eligible securities are ranked by their momentum score and the top 50% of companies by fundamental weight are selected for inclusion. A company’s fundamental weight may be adjusted by a “free float factor”, which is the ratio of the total market capitalization of the shares of the company in free float to the total market capitalization of the company. As of September 30, 2021, the Underlying Index consisted of 730 Component Securities.

The Underlying Index dynamically allocates to each factor at each quarterly rebalance. Dynamic allocation starts with an equal weighting to each factor plus an additional weight, which is based on a calculation of a factor’s standard momentum and long-term reversal signal relative to the other factors. Additional weights to a particular factor are capped at a maximum of 15% and minimum of -15% relative to equal weighting.

Each factor (other than momentum) is reconstituted annually on the last business day of March and rebalanced on a quarterly staggered basis on the last business day of March, June, September and third Friday of December. For example, a single factor will be divided into four identical tranches. At the first quarterly rebalance, the first tranche (i.e., 25% of the factor) is rebalanced, but the remaining three tranches (i.e., the other 75% of the factor) are not rebalanced and will continue to drift until the next quarterly rebalance. At the next quarterly rebalance, the second tranche is rebalanced while the other three tranches (including the tranche that was rebalanced at the prior quarter-end) are not rebalanced. This staggered rebalancing is intended to diversify risk and decrease market impact. The momentum factor, unlike the other factors, is reconstituted and fully rebalanced quarterly. At each quarterly rebalance, trading controls are implemented to minimize turnover.

outperform the index the Fund tracks. An indexing approach may eliminate the chance that the Fund will substantially outperform its Underlying Index but also may reduce some of the risks of active management. Indexing seeks to achieve lower costs by keeping portfolio turnover low in comparison to actively managed investment companies.

The Fund may invest, without limitation, in equity and equity-related securities, including common and preferred securities. The Fund may also invest in derivative instruments, such as options, futures contracts or swap agreements. The Fund may invest, without limitation, in securities and instruments denominated in foreign currencies and in securities of foreign issuers. The Fund may invest, without limitation, in securities and instruments that are economically tied to emerging market countries. The Fund may obtain foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) without limitation.

Principal Risks

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Market Trading Risk: the risk that an active secondary trading market for Fund shares does not continue once developed, that the Fund may not continue to meet a listing exchange’s trading or listing requirements, or that Fund shares trade at prices other than the Fund’s net asset value, particularly during times of market stress

Equity Risk: the risk that the value of equity securities, such as common stocks and preferred securities, may decline due to general market conditions which are not specifically related to a particular company or to factors affecting a particular industry or industries. Equity securities generally have greater price volatility than fixed income securities

Credit Risk: the risk that the Fund could lose money if the counterparty to a derivative contract is unable or unwilling, or is perceived (whether by market participants, rating agencies, pricing services or otherwise) as unable or unwilling, to meet its financial obligations

Market Risk: the risk that the value of securities owned by the Fund may go up or down, sometimes rapidly or unpredictably, due to factors affecting securities markets generally or particular industries

Liquidity Risk: the risk that a particular investment may be difficult to purchase or sell and that the Fund may be unable to sell illiquid investments at an advantageous time or price or achieve its desired level of exposure to a certain sector. The liquidity of the Fund’s shares may be constrained by the liquidity of the Fund’s portfolio holdings

Issuer Risk: the risk that the value of a security may decline for a reason directly related to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods or services

Derivatives Risk: the risk of investing in derivative instruments (such as futures, swaps and structured securities), including leverage, liquidity,

2 Prospectus | PIMCO Equity Series

Prospectus

interest rate, market, credit and management risks and valuation complexity. Changes in the value of a derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund’s use of derivatives may result in losses to the Fund, a reduction in the Fund’s returns and/or increased volatility. Over-the-counter (“OTC”) derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. The primary credit risk on derivatives that are exchange-traded or traded through a central clearing counterparty resides with the Fund's clearing broker, or the clearinghouse. Changes in regulation relating to a fund’s use of derivatives and related instruments could potentially limit or impact the Fund’s ability to invest in derivatives, limit the Fund’s ability to employ certain strategies that use derivatives and/or adversely affect the value of derivatives and the Fund’s performance

Foreign (Non-U.S.) Investment Risk: the risk that investing in foreign (non-U.S.) securities may result in the Fund experiencing more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. companies, due to smaller markets, differing reporting, accounting and auditing standards, increased risk of delayed settlement of portfolio transactions or loss of certificates of portfolio securities, and the risk of unfavorable foreign government actions, including nationalization, expropriation or confiscatory taxation, currency blockage, or political changes or diplomatic developments. Foreign securities may also be less liquid and more difficult to value than securities of U.S. issuers

Emerging Markets Risk: the risk of investing in emerging market securities, primarily increased foreign (non-U.S.) investment risk

Currency Risk: the risk that foreign (non-U.S.) currencies will change in value relative to the U.S. dollar and affect the Fund’s investments in foreign (non-U.S.) currencies or in securities that trade in, and receive revenues in, or in derivatives that provide exposure to, foreign (non-U.S.) currencies

Model Risk: the risk that the Fund’s investment models used in making investment allocation decisions, including the indexation methodologies used in constructing the Underlying Index, may not adequately take into account certain factors, may contain design flaws or faulty assumptions, and may rely on incomplete or inaccurate data, any of which may result in a decline in the value of an investment in the Fund

Leveraging Risk: the risk that certain transactions of the Fund, such as reverse repurchase agreements, loans of portfolio securities, and the use of when-issued, delayed delivery or forward commitment transactions, or derivative instruments, may give rise to leverage, magnifying gains and losses and causing the Fund to be more volatile than if it had not been leveraged. This means that leverage entails a heightened risk of loss

Management and Tracking Error Risk: the risk that the portfolio manager’s investment decisions may not produce the desired results or that the Fund’s portfolio may not closely track the Underlying Index for a number of reasons. The Fund incurs operating expenses, which are not applicable to the Underlying Index, and the costs of buying and selling securities, especially when rebalancing the Fund’s portfolio to reflect changes in the composition of the Underlying Index. Performance of the Fund and the Underlying Index may vary due to asset valuation differences and differences between the Fund’s portfolio and the Underlying Index due to legal restrictions, cost or liquidity restraints. The risk that performance of the Fund and the Underlying Index may vary may be heightened during periods of increased market volatility or other unusual market conditions. In addition, the Fund’s use of a representative sampling approach may cause the Fund to be less correlated to the return of the Underlying Index than if the Fund held all of the securities in the Underlying Index

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

Please see “Description of Principal Risks” in the Fund's prospectus for a more detailed description of the risks of investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Performance Information

The performance information shows summary performance information for the Fund in a bar chart and an Average Annual Total Returns table. The information provides some indication of the risks of investing in the Fund by showing changes in its performance from year to year and by showing how the Fund’s average annual returns compare with the returns of a broad-based securities market index. Absent any applicable fee waivers and/or expense limitations, performance would have been lower. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future.

The Fund measures its performance against a primary benchmark and a secondary benchmark. The Fund’s primary benchmark is the RAFI Dynamic Multi-Factor Emerging Market Index. The RAFI Dynamic Multi-Factor Emerging Markets Index consists of “factor portfolios,” each of which emphasizes one of the following factors: value, low volatility, quality and momentum and is designed to provide long-only exposure to multiple equity factors that seek to produce attractive long-term returns, and which may lower risk compared to less diversified strategies. The Fund’s secondary benchmark is the MSCI Emerging Market Index. The MSCI Emerging Market Index is a free float-adjusted market capitalization index that is designed to measure equity market performance of emerging markets. Performance for the Fund is updated daily and quarterly and may be obtained as follows: daily and quarterly updates on the net asset value and performance page at https://www.pimco.com/en-us/investments/etf.

November 1, 2021 | Prospectus 3

PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF

Calendar Year Total Returns

Best Quarter	December 31, 2020	22.44%
Worst Quarter	March 31, 2020	-29.39%
Year-to-Date	September 30, 2021	9.47%

Average Annual Total Returns (for periods ended 12/31/20)

	1 Year	Since Inception	Inception Date
Return Before Taxes	12.02%	4.90%	8/31/2017
Return After Taxes on Distributions(1)	11.26%	4.13%
Return After Taxes on Distributions and Sales of Fund Shares(1)	7.18%	3.50%
RAFI Dynamic Multi-Factor Emerging Markets Index (reflects no deductions for fees, expenses or taxes)	12.98%	5.36%
MSCI Emerging Markets Index (reflects no deductions for fees, expenses or taxes)	18.31%	7.70%

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

Investment Adviser/Portfolio Manager

PIMCO serves as the investment adviser for the Fund. Parametric Portfolio Associates LLC serves as the Fund’s sub-adviser. The Fund’s portfolio is managed by Thomas Seto. Mr. Seto is the Head of Investment Management and a Managing Director of Parametric Portfolio Associates LLC, and has managed the Fund since its inception in August 2017.

Other Important Information Regarding Fund Shares

For important information about purchase and sale of Fund shares, tax information, and payments to broker-dealers and other financial intermediaries, please turn to the “Summary of Other Important Information Regarding Fund Shares” section on page 17 of this prospectus.

4 Prospectus | PIMCO Equity Series

PIMCO RAFI Dynamic Multi-Factor

International Equity ETF

Investment Objective

The Fund seeks to track the investment results of the RAFI Dynamic Multi-Factor Developed Ex-U.S. Index.

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment):

N/A

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

Management Fees	0.39%
Total Annual Fund Operating Expenses	0.39%

Example.

The Example is intended to help you compare the cost of investing in the Fund with the costs of investing in other exchange-traded funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated, and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. 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
$40	$125	$219	$493

Portfolio Turnover

Principal Investment Strategies

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities (“Component Securities”) of the RAFI Dynamic Multi-Factor Developed Ex-U.S. Index (the “Underlying Index”). The Fund may invest the remainder of its assets in cash, securities and instruments that are not Component Securities, but which the Fund’s sub-adviser, Parametric Portfolio Associates LLC (“Sub-Adviser”), believes will help the Fund track its Underlying Index. The Underlying Index is designed to provide

long-only exposure to multiple equity factors that seek to produce attractive long-term returns, and which may lower risk compared to less diversified strategies.

The Underlying Index is constructed by RAFI Indices, LLC (the “Index Provider”) using a rules-based approach to construct factor portfolios within the Underlying Index. The universe for the Underlying Index construction process starts with all common equity securities traded on primary exchanges, and preferred shares in countries where preferred shares are economically equivalent to common, which meet and pass minimum liquidity and investability (capacity) requirements, issued by companies that are assigned to countries classified by the Index Provider to fall within the following regions, Developed Europe ex-U.K., U.K., Japan and Other Developed Markets. As of September 30, 2021, there are 22 developed market countries (excluding the United States) eligible for inclusion. The Index Provider assigns companies to countries and promulgates that assignment to securities. Eligible securities are then determined by selecting companies based on fundamental weight, calculated using four accounting measures from company financial statements: (i) de-levered sales, calculated as company sales averaged over the past five years multiplied by the ratio of average equity to average assets; (ii) cash flow, taken as the company operating cash flow averaged over the past five years; (iii) dividend plus buybacks, calculated using the average dividends paid and share buybacks over the past five years; and (iv) book value, taken as the most recent company book value. At each annual reconstitution, companies that rank in the top 86% of cumulative fundamental weight within each region constitute the large/mid company universe. Companies that rank in the top 98% by fundamental weight, excluding companies in the top 86%, within each region constitute the small company universe.

The Underlying Index consists of “factor portfolios,” each of which emphasizes one of the following factors: value, low volatility, quality, momentum and size. The value factor emphasizes companies with high ratio of company fundamental weight to its market capitalization weight. The low volatility factor emphasizes companies with low risk measure calculated as the variance of a company’s daily excess return over five years explained by global, local country groups, and global industry excess returns. The quality factor emphasizes companies that are high in profitability and low in investment spending. The momentum factor emphasizes stocks with high momentum. For the value, low volatility and quality “factor portfolios”, eligible securities are ranked by their factor score and the top 25% of companies by fundamental weight are selected for inclusion within that “factor portfolio”. For the momentum “factor portfolio”, eligible securities are ranked by their momentum score and the top 50% of companies by fundamental weight are selected for inclusion. The size factor is the equal weight of the small company portions of the other four factors. A company’s fundamental weight may be adjusted by a “free float factor”, which is the ratio of the total market capitalization of the shares of the company in free float to the total market capitalization of the company. As of September 30, 2021, the Underlying Index consisted of 1,968 Component Securities.

PIMCO Equity Series | Prospectus 5

PIMCO RAFI Dynamic Multi-Factor International Equity ETF

The Sub-Adviser uses an indexing approach in managing the Fund’s investments. The Fund employs a representative sampling strategy in seeking to achieve its investment objective. In using this strategy, the Sub-Adviser seeks to invest in a combination of Component Securities and other instruments, or in Component Securities but in different proportions as compared to the weighting of the Underlying Index, such that the portfolio effectively provides exposure to the Underlying Index. In using a representative sampling strategy, the Fund may not track its Underlying Index with the same degree of accuracy as a fund that replicates the composition and weighting of the Underlying Index. Unlike many investment companies, the Fund does not attempt to outperform the index the Fund tracks. An indexing approach may eliminate the chance that the Fund will substantially outperform its Underlying Index but also may reduce some of the risks of active management. Indexing seeks to achieve lower costs by keeping portfolio turnover low in comparison to actively managed investment companies.

The Fund may invest, without limitation, in equity and equity-related securities, including common and preferred securities. The Fund may also invest in derivative instruments, such as options, futures contracts or swap agreements. The Fund may invest, without limitation, in securities and instruments denominated in foreign currencies and in securities of foreign issuers. The Fund may obtain foreign currency exposure (from non-U.S. dollar-denominated securities or currencies) without limitation.

Principal Risks

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Small Fund Risk: the risk that a smaller fund may not achieve investment or trading efficiencies. Additionally, a smaller fund may be more adversely affected by large purchases or redemptions of fund shares

Derivatives Risk: the risk of investing in derivative instruments (such as futures , swaps and structured securities), including leverage, liquidity, interest rate, market, credit and management risks, and valuation complexity. Changes in the value of a derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund’s use of derivatives may result in losses to the Fund, a reduction in the Fund’s returns and/or increased volatility. Over-the-counter (“OTC”) derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. The primary credit risk on derivatives that are exchange-traded or traded through a central clearing counterparty resides with the Fund's clearing broker, or the clearinghouse. Changes in regulation relating to a fund’s use of derivatives and related instruments could potentially limit or impact the Fund’s ability to invest in derivatives, limit the Fund’s ability to employ certain strategies that use

6 Prospectus | PIMCO Equity Series

Prospectus

derivatives and/or adversely affect the value of derivatives and the Fund’s performance

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

Performance Information

The Fund measures its performance against a primary benchmark and a secondary benchmark. The Fund’s primary benchmark is the RAFI Dynamic Multi-Factor Developed ex-U.S. Index. The RAFI Dynamic Multi-Factor Developed Ex-U.S. Index consists of “factor portfolios,” each of which emphasizes one of the following factors: value, low volatility, quality, momentum and size and is designed to provide long-only exposure to multiple equity factors that seek to produce attractive long-term returns, and which may lower risk compared to less diversified strategies. The Fund’s secondary benchmark is the MSCI EAFE Index. The MSCI EAFE Index is an unmanaged index designed to represent the performance of large and mid-cap securities across 21 developed markets, including countries in Europe, Australasia and the Far East, excluding the U.S. and Canada. Performance for the Fund is updated daily and quarterly and may be obtained as follows: daily and quarterly updates on the net asset value and performance page at https://www.pimco.com/en-us/investments/etf.

Calendar Year Total Returns

Best Quarter	June 30, 2020	15.82%
Worst Quarter	March 31, 2020	-23.62%
Year-to-Date	September 30, 2021	8.34%

November1, 2021 | Prospectus 7

PIMCO RAFI Dynamic Multi-Factor International Equity ETF

Average Annual Total Returns (for periods ended 12/31/20)

	1 Year	Since Inception	Inception Date
Return Before Taxes	7.24%	5.33%	8/31/2017
Return After Taxes on Distributions(1)	6.71%	4.66%
Return After Taxes on Distributions and Sales of Fund Shares(1)	4.47%	3.99%
RAFI Dynamic Multi-Factor Developed Ex-U.S. Index (reflects no deductions for fees, expenses or taxes)	7.64%	5.84%
MSCI EAFE Index (reflects no deductions for fees, expenses or taxes)	7.82%	5.92%

Investment Adviser/Portfolio Manager

Other Important Information Regarding Fund Shares

8 Prospectus | PIMCO Equity Series

PIMCO RAFI Dynamic Multi-Factor

U.S. Equity ETF

Investment Objective

The Fund seeks to track the investment results of the RAFI Dynamic Multi-Factor U.S. Index.

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment):

N/A

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

Management Fees	0.29%
Other Expenses(1)	0.01%
Total Annual Fund Operating Expenses	0.30%
Fee Waiver and/or Expense Reimbursement(2)	(0.01%)
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	0.29%

Example.

1 Year	3 Years	5 Years	10 Years
$30	$95	$168	$380

Portfolio Turnover

Principal Investment Strategies

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities (“Component Securities”) of the RAFI Dynamic Multi-Factor U.S. Index (the “Underlying Index”). The Fund may invest the remainder of its assets in cash, securities and instruments that are not Component Securities, but which the Fund’s sub-adviser, Parametric Portfolio Associates LLC (“Sub-Adviser”), believes will help the Fund track its Underlying Index. The Underlying Index is designed to provide long-only exposure to multiple equity factors that seek to produce attractive long-term returns, and which may lower risk compared to less diversified strategies.

The Underlying Index is constructed by RAFI Indices, LLC (the “Index Provider”) using a rules-based approach to construct factor portfolios within the Underlying Index. The universe for the Underlying Index construction process starts with all common equity securities traded on primary exchanges, which meet and pass minimum liquidity and investability (capacity) requirements, issued by companies that are assigned to the United States by the Index Provider. The Index Provider assigns companies to countries and promulgates that assignment to securities. Eligible securities are then determined by selecting companies based on fundamental weight, calculated using four accounting measures from company financial statements: (i) de-levered sales, calculated as company sales averaged over the past five years multiplied by the ratio of average equity to average assets; (ii) cash flow, taken as the company operating cash flow averaged over the past five years; (iii) dividend plus buybacks, calculated using the average dividends paid and share buybacks over the past five years; and (iv) book value, taken as the most recent company book value. At each annual reconstitution, companies that rank in the top 86% of cumulative fundamental weight within each region constitute the large/mid company universe. Companies that rank in the top 98% by fundamental weight, excluding companies in the top 86%, within each region constitute the small company universe.

PIMCO Equity Series | Prospectus 9

PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF

industry excess returns. The quality factor emphasizes companies that are high in profitability and low in investment spending. The momentum factor emphasizes stocks with high momentum. For the value, low volatility and quality “factor portfolios”, eligible securities are ranked by their factor score and the top 25% of companies by fundamental weight are selected for inclusion within that “factor portfolio”. For the momentum “factor portfolio”, eligible securities are ranked by their momentum score and the top 50% of companies by fundamental weight are selected for inclusion. The size factor is the equal weight of the small company portions of the other four factors. A company’s fundamental weight may be adjusted by a “free float factor”, which is the ratio of the total market capitalization of the shares of the company in free float to the total market capitalization of the company. As of September 30, 2021, the Underlying Index consisted of 908 Component Securities.

The Sub-Adviser uses an indexing approach in managing the Fund’s investments. The Fund is expected to employ a replication strategy in seeking to achieve its investment objective. In using this strategy, the Sub-Adviser seeks to replicate the composition and weighting of the Underlying Index by investing all, or substantially all, of the Fund’s assets in the Component Securities, holding each Component Security in approximately the same proportion as its weighting in the Underlying Index. However, in some circumstances it may not be possible or practicable to invest all, or substantially all, of the Fund’s assets in the Component Securities, in which case the Fund may employ a representative sampling strategy by investing in a combination of Component Securities and other instruments, or in Component Securities but in different proportions as compared to the weighting of the Underlying Index, such that the portfolio effectively provides exposure to the Underlying Index. In using a representative sampling strategy, the Fund may not track its Underlying Index with the same

degree of accuracy as a fund that replicates the composition and weighting of the Underlying Index. Unlike many investment companies, the Fund does not attempt to outperform the index the Fund tracks. An indexing approach may eliminate the chance that the Fund will substantially outperform its Underlying Index but also may reduce some of the risks of active management. Indexing seeks to achieve lower costs by keeping portfolio turnover low in comparison to actively managed investment companies.

Principal Risks

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

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Prospectus

Management and Tracking Error Risk: the risk that the portfolio manager’s investment decisions may not produce the desired results or that the Fund’s portfolio may not closely track the Underlying Index for a number of reasons. The Fund incurs operating expenses, which are not applicable to the Underlying Index, and the costs of buying and selling securities, especially when rebalancing the Fund’s portfolio to reflect changes in the composition of the Underlying Index. Performance of the Fund and the Underlying Index may vary due to asset valuation differences and differences between the Fund’s portfolio and the Underlying Index due to legal restrictions, cost or liquidity restraints. The risk that performance of the Fund and the Underlying Index may vary may be heightened during periods of increased market volatility or other unusual market conditions. In addition, to the extent the Fund uses a representative sampling approach, this approach may cause the Fund to be less correlated to the return of the Underlying Index than if the Fund held all of the securities in the Underlying Index

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

Performance Information

The Fund measures its performance against a primary benchmark and a secondary benchmark. The Fund’s primary benchmark is the RAFI Dynamic Multi-Factor U.S. Index. The RAFI Dynamic Multi-Factor U.S. Index consists of “factor portfolios,” each of which emphasizes one of the following factors: value, low volatility, quality, momentum and size and is designed to provide long-only exposure to multiple equity factors that seek to produce attractive long-term returns, and which may lower risk compared to less diversified strategies. The Fund’s secondary benchmark is the S&P 500 Index. The S&P 500 Index is an unmanaged market index generally considered representative of the stock market as a whole. The Index focuses on the large-cap segment of the U.S. equities market. Performance for the Fund is updated daily and quarterly and may be obtained as follows: daily and quarterly updates on the net asset value and performance page at https://www.pimco.com/en-us/investments/etf.

Calendar Year Total Returns

Best Quarter	June 30, 2020	18.22%
Worst Quarter	March 31, 2020	-24.22%
Year-to-Date	September 30, 2021	14.58%

November1, 2021 | Prospectus 11

PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF

Average Annual Total Returns (for periods ended 12/31/20)

	1 Year	Since Inception	Inception Date
Return Before Taxes	10.55%	11.75%	8/31/2017
Return After Taxes on Distributions(1)	9.94%	11.13%
Return After Taxes on Distributions and Sales of Fund Shares(1)	6.44%	9.05%
RAFI Dynamic Multi-Factor U.S. Index (reflects no deductions for fees, expenses or taxes)	10.96%	12.17%
S&P 500 Index (reflects no deductions for fees, expenses or taxes)	18.40%	15.56%

Investment Adviser/Portfolio Manager

Other Important Information Regarding Fund Shares

12 Prospectus | PIMCO Equity Series

PIMCO RAFI ESG U.S. ETF

Investment Objective

The Fund seeks to provide total return that closely corresponds, before fees and expenses, to the total return of the RAFI ESG US Index.

Fees and Expenses of the Fund

Shareholder Fees (fees paid directly from your investment):

N/A

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):

Management Fees	0.29%
Other Expenses(1)	0.01%
Total Annual Fund Operating Expenses	0.30%
Fee Waiver and/or Expense Reimbursement(2)	(0.01%)
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	0.29%

PIMCO has contractually agreed, through October 31, 2022, to waive a portion of the Fund’s management fees, or reimburse the Fund, to the extent that the Fund’s organizational expenses, pro rata share of expenses related to obtaining or maintaining a Legal Entity Identifier and pro rata share of Trustee fees exceed 0.0049% (the “Expense Limit”) (calculated as a percentage of average daily net assets). This Expense Limitation Agreement will automatically renew for one-year terms unless PIMCO provides written notice to PIMCO Equity Series at least 30 days prior to the end of the then current term. In any month in which the management agreement is in effect, PIMCO is entitled to reimbursement by the Fund of any portion of the management fee waived or reimbursed as set forth above (the “Reimbursement Amount”) during the previous thirty-six months from the time of the waiver, provided that such amount paid to PIMCO will not: 1) together with any organizational expenses, pro rata share of expenses related to obtaining or maintaining a Legal Entity Identifier and pro rata Trustee fees, exceed, for such month, the Expense Limit (or the amount of the expense limit in place at the time the amount being recouped was originally waived if lower than the Expense Limit); 2) exceed the total Reimbursement Amount; or 3) include any amounts previously reimbursed to PIMCO.

Example.

1 Year	3 Years	5 Years	10 Years
$30	$95	$168	$380

Portfolio Turnover

Principal Investment Strategies

The Fund seeks to achieve its investment objective by investing under normal circumstances at least 80% of its total assets (exclusive of collateral held from securities lending) in the component securities (“Component Securities”) of the RAFI ESG US Index (the “Underlying Index”). The Fund may invest the remainder of its assets in cash, securities and instruments that are not Component Securities, but which the Fund’s sub-adviser, Parametric Portfolio Associates LLC (“Sub-Adviser”), believes will help the Fund track its Underlying Index. The Underlying Index is a long-only, smart beta index that seeks to achieve the dual objectives of social responsibility and long-horizon outperformance of the broad market.

The Underlying Index is constructed by RAFI Indices, LLC (the “Index Provider”) using a rules-based approach within publicly traded U.S. equities to create an integrated ESG strategy which overweights companies that rate well across various ESG (Environmental, Social, and Governance) themes and excludes companies with a major involvement in industries such as tobacco, gaming, weapons and fossil fuels. The strategy supplements traditional ESG metrics with metrics linked to long-term value creation, specifically financial discipline and diversity, for improved return potential.

The Underlying Index applies the Fundamental Index™ approach, a smart beta strategy built on the principles of contrarian indexing and disciplined rebalancing. The universe for the Underlying Index construction process starts with all common equity securities traded on U.S. primary exchanges, which meet and pass minimum liquidity and investability (capacity) requirements, issued by companies that are assigned to the United States by the Index Provider. Eligible securities are then determined by selecting companies based on fundamental weight, calculated using four accounting measures from company financial statements: (i) de-levered sales, calculated as company sales averaged over the past five years multiplied by the ratio of average equity to average assets; (ii) cash flow, taken as the company operating cash flow averaged over the past five years; (iii) dividend plus buybacks, calculated using the average dividends paid and share buybacks over the past five years; and (iv) book value, taken as the most recent company book value. The Underlying Index is composed of securities selected from companies in the large/mid company universe, which is the universe of companies that rank in the top 86% of cumulative fundamental weight.

PIMCO Equity Series | Prospectus 13

PIMCO RAFI ESG U.S. ETF

The Underlying Index uses five signals to determine a company’s overall ESG score: environment, social, governance, diversity and financial discipline. The environment, social, governance and diversity scores are determined using data provided by Vigeo Eiris, a third-party ESG data and ratings provider (the “ESG Data Provider”). The ESG Data Provider assesses hundreds of different factors within a framework of sustainability criteria based on international standards in determining the environment, social and governance scores. The ESG Data Provider also considers numerous different metrics relating to gender diversity in determining the diversity scores. The financial discipline score is determined by the Index Provider and is intended to identify companies with high profitability, low investment, low issuance and low accruals. To construct the Underlying Index, companies are sorted in descending order by their environment, social, governance, diversity and financial discipline scores, respectively.

Companies in the bottom 10% by fundamental weight, for each respective signal, are excluded. In addition, companies classified by the ESG Data Provider as having major involvement in the following areas are excluded: tobacco, gambling, weapons - civilian firearms and military, fossil fuels, coal, tar sands and oil shale. Selected companies are weighted by their fundamental weight, adjusted by the companies’ respective overall ESG scores. As of September 30, 2021, the Underlying Index consisted of 284 Component Securities.

The Underlying Index is reconstituted annually on the last business day of March and rebalanced on a quarterly staggered basis on the last business day of March, June, September and third Friday of December. For example, the Underlying Index will be divided into four identical tranches. At the first quarterly rebalance, the first tranche (i.e., 25% of the Underlying Index) is rebalanced, but the remaining three tranches (i.e., the other 75% of the Underlying Index) are not rebalanced and will continue to drift until the next quarterly rebalance. At the next quarterly rebalance, the second tranche is rebalanced while the other three tranches (including the tranche that was rebalanced at the prior quarter-end) are not rebalanced. This staggered rebalancing is intended to diversify risk and decrease market impact of trading.

weighting of the Underlying Index. Unlike many investment companies, the Fund does not attempt to outperform the index the Fund tracks. An indexing approach may eliminate the chance that the Fund will substantially outperform its Underlying Index but also may reduce some of the risks of active management. Indexing seeks to achieve lower costs by keeping portfolio turnover low in comparison to actively managed investment companies.

Principal Risks

It is possible to lose money on an investment in the Fund. The principal risks of investing in the Fund, which could adversely affect its net asset value, yield and total return, are listed below.

Small Fund Risk: the risk that a smaller Fund may not achieve investment or trading efficiencies. Additionally, a smaller Fund may be more adversely affected by large purchases or redemptions of Fund shares

Derivatives Risk: the risk of investing in derivative instruments (such as futures , swaps and structured securities), including leverage,

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Prospectus

liquidity, interest rate, market, credit and management risks, and valuation complexity. Changes in the value of a derivative may not correlate perfectly with, and may be more sensitive to market events than, the underlying asset, rate or index, and the Fund could lose more than the initial amount invested. The Fund’s use of derivatives may result in losses to the Fund, a reduction in the Fund’s returns and/or increased volatility. Over-the-counter (“OTC”) derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. The primary credit risk on derivatives that are exchange-traded or traded through a central clearing counterparty resides with the Fund's clearing broker, or the clearinghouse. Changes in regulation relating to a fund’s use of derivatives and related instruments could potentially limit or impact the Fund’s ability to invest in derivatives, limit the Fund’s ability to employ certain strategies that use derivatives and/or adversely affect the value of derivatives and the Fund’s performance

Management and Tracking Error Risk: the risk that the portfolio manager’s investment decisions may not produce the desired results or that the Fund’s portfolio may not closely track the Underlying Index for a number of reasons. The Fund incurs operating expenses, which are not applicable to the Underlying Index, and the costs of buying and selling securities, especially when rebalancing the Fund’s portfolio to reflect changes in the composition of the Underlying Index. Performance of the Fund and the Underlying Index may vary due to asset valuation differences and differences between the Fund’s portfolio and the Underlying Index due to legal restrictions, cost or liquidity restraints. The risk that performance of the Fund and the Underlying Index may vary may be heightened during periods of increased market volatility or other unusual market conditions. In addition, to the extent the Fund uses a representative sampling approach, this approach may cause the Fund to be less correlated to the return of the Underlying Index than if the Fund held all of the securities in the Underlying Index

Indexing Risk: the risk that the Fund is negatively affected by general declines in the asset classes represented by the Underlying Index

Environmental, Social and Governance Investing Risk: the risk that, because the Underlying Index may select or exclude securities of certain issuers for reasons other than performance, the Fund’s performance will differ from funds that do not utilize an ESG investing strategy. ESG investing is qualitative and subjective by nature, and there is no guarantee that the factors utilized by the Index Provider or any judgment exercised by the Index Provider in constructing the Underlying Index will reflect the opinions of any particular investor

Performance Information

The Fund measures its performance against a primary benchmark and a secondary benchmark. The Fund’s primary benchmark is the RAFI ESG US Index. The RAFI ESG US Index is a long-only, smart beta index that seeks to achieve the dual objectives of social responsibility and long-horizon outperformance of the broad market and is composed of securities selected from companies in the large/mid company universe, which is the universe of companies that rank in the top 86% of cumulative fundamental weight. The Fund’s secondary benchmark is the S&P 500 Index. The S&P 500 Index is an unmanaged market index generally considered representative of the stock market as a whole. The Index focuses on the large-cap segment of the U.S. equities market. Performance for the Fund is updated daily and quarterly and may be obtained as follows: daily and quarterly updates on the net asset value and performance page at https://www.pimco.com/en-us/investments/etf.

November 1, 2021 | Prospectus 15

PIMCO RAFI ESG U.S. ETF

Calendar Year Total Returns

Best Quarter	December 31, 2020	15.98%
Worst Quarter	March 31, 2020	-25.64%
Year-to-Date	September 30, 2021	18.31%

Average Annual Total Returns (for periods ended 12/31/20)

	1 Year	Since Inception	Inception Date
Return Before Taxes	5.41%	6.24%	12/18/2019
Return After Taxes on Distributions(1)	4.64%	5.45%
Return After Taxes on Distributions and Sales of Fund Shares(1)	3.48%	4.52%
RAFI ESG US Index (reflects no deductions for fees, expenses or taxes)	5.78%	6.57%
S&P 500 Index (reflects no deductions for fees, expenses or taxes)	18.40%	19.13%

Investment Adviser/Portfolio Manager

Other Important Information Regarding Fund Shares

16 Prospectus | PIMCO Equity Series

Summary of Other Important Information Regarding Fund Shares

Purchase and Sale of Fund Shares

Each Fund is an exchange-traded fund (“ETF”). Individual Fund shares may only be purchased and sold on a national securities exchange through a broker-dealer and may not be purchased or redeemed directly with a Fund. The price of Fund shares is based on market price, and because ETF shares trade at market prices rather than net asset value (“NAV”), shares may trade at a price greater than NAV (a premium) or less than NAV (a discount). An investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase shares of a Fund (“bid”) and the lowest price a seller is willing to accept for shares (“ask”) when buying or selling shares in the secondary market (the “bid-ask spread”). Recent information, including information about each Fund’s NAV, market price, premiums and discounts, and bid-ask spreads, is included on the Fund’s website at https://www.pimco.com/en-us/investments/etf.

Tax Information

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

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase Fund shares through a broker-dealer or other financial intermediary, PIMCO or other related companies may pay the intermediary for the sale of Fund shares or related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

Summary Information About the Funds

This prospectus describes four ETFs (each a “Fund,” collectively the “Funds”) offered by PIMCO Equity Series (the “Trust”). The Funds provide access to the professional investment advisory services offered by PIMCO. PIMCO has engaged Parametric Portfolio Associates LLC (“Parametric” or “Sub-Adviser”) to serve as sub-adviser to each Fund. References to “the Fund” or “a Fund” relate to all Funds unless the context requires otherwise.

ETFs are funds that trade like other publicly-traded securities and may be designed to track an index or to be actively managed. Similar to shares of an index mutual fund, each share of the Fund represents a partial ownership of the fund which owns an underlying portfolio of securities intended to track an index. Unlike shares of a mutual fund, which can be bought from and redeemed by the issuing fund by all shareholders at a price based on NAV, shares of a Fund may be directly purchased from and redeemed by the Fund at NAV solely by a member or participant of a clearing agency registered with the Securities and Exchange Commission (the “SEC”), which has a written agreement with

the Fund’s Distributor that allows such member or participant to place orders for the purchase and redemption of Creation Units (as defined below) (“Authorized Participant”). Also unlike shares of a mutual fund, shares of ETFs are listed on a national securities exchange and trade in the secondary market at market prices that change throughout the day.

Shares of a Fund are listed and traded at market prices on NYSE Arca, Inc. (“NYSE Arca”) and other secondary markets. The market price for a Fund’s shares may be different from the Fund’s NAV. The Funds issue and redeem shares at NAV only in aggregations of a specified number of shares (“Creation Units”). Only Authorized Participants may purchase or redeem Creation Units directly with the Fund at NAV. These transactions are in exchange for securities and/or cash. Except when aggregated in Creation Units, shares of a Fund are not redeemable securities. Shareholders who are not Authorized Participants may not purchase or redeem shares directly from a Fund.

If a Fund were to effect redemptions with an Authorized Participant primarily for cash, the Fund may be required to sell portfolio securities in order to obtain the cash needed to distribute redemption proceeds. The sale of portfolio securities could cause a Fund to recognize gains that it might not otherwise have recognized if redemptions were effected in-kind, or to recognize such gain sooner than would otherwise be required. Such gains will generally be distributed to shareholders to avoid taxation at the Fund level and to ensure compliance with other special tax rules that apply to the Funds. Moreover, the sale of portfolio securities will generally subject the Funds to transaction costs, which may be partially or totally offset by the variable transaction fee charged by the Funds to redeeming Authorized Participants.

A Fund invests in a particular segment of the securities markets and seeks to track the performance of an index that is not representative of the broader securities markets. An investment in a particular Fund alone should not constitute an entire investment program. This prospectus explains what you should know about the Funds before you invest. Please read it carefully. Certain affiliates of the Funds and PIMCO may purchase and resell Fund shares pursuant to this prospectus. Fund fact sheets provide additional information regarding the Funds and may be requested by calling 1.888.400.4ETF (1.888.400.4383).

November1, 2021 | Prospectus 17

PIMCO Equity Series

Description of Principal Risks

The value of your investment in a Fund changes with the market price of the Fund’s shares determined in the secondary market. Market price may be determined, in part, by the values of a Fund’s investments. Many factors can affect those values. The factors that are most likely to have a material effect on a particular Fund’s portfolio as a whole are called “principal risks.” The principal risks of each Fund are identified in the Fund Summaries. The principal risks are described in more detail in this section. Each Fund may be subject to additional risks other than those identified and described below because the types of investments made by a Fund can change over time. Securities and investment techniques mentioned in this summary that appear in bold type are described in greater detail under “Characteristics and Risks of Securities and Investment Techniques.” That section and “Investment Objectives and Policies” in the Statement of Additional Information (the “SAI”) also include more information about the Funds, their investments and the related risks. There is no guarantee that a Fund will be able to achieve its investment objective. It is possible to lose money by investing in a Fund.

Small Fund Risk

A smaller fund may not grow to or maintain an economically viable size to achieve investment or trading efficiencies, which may negatively impact performance and/or force the fund to liquidate. Additionally, a smaller fund may be more adversely affected by large purchases or redemptions of fund shares, which can occur at any time and may impact the fund in the same manner as a high volume of purchases or redemptions.

Market Trading Risk

Each Fund is subject to secondary market trading risks. Shares of a Fund are listed for trading on an exchange, however, there can be no guarantee that an active trading market for such shares will develop or continue. Shares of a Fund may be listed or traded on U.S. and foreign (non-U.S.) exchanges other than the Fund’s primary U.S. listing exchange. There can be no guarantee that a Fund’s shares will continue trading on any exchange or in any market or that the Fund’s shares will continue to meet the listing or trading requirements of any exchange or market. A Fund’s shares may experience higher trading volumes on one exchange as compared to another and investors are subject to the execution and settlement risks of the market where their broker directs trades.

Secondary market trading in a Fund’s shares may be halted by an exchange because of market conditions. Pursuant to exchange or market rules, trading in a Fund’s shares on an exchange or in any market may be subject to trading halts caused by extraordinary market volatility. If secondary market trading is halted or an exchange closes earlier than anticipated, you may be unable to purchase or sell Fund shares. There can be no guarantee that a Fund’s exchange listing or ability to trade its shares will continue or remain unchanged. In the event a Fund ceases to be listed on an exchange, the Fund may cease operating as an “exchange-traded” fund and operate as a mutual fund, provided that shareholders are given advance notice.

Buying or selling a Fund’s shares on an exchange may require the payment of brokerage commissions. In addition, you may also incur the cost of the spread (the difference between the bid price and the ask price). The commission is frequently a fixed amount and may be a significant cost for investors seeking to buy or sell small amounts of shares. The spread varies over time for shares of a Fund based on their trading volume and market liquidity, and is generally less if the Fund has more trading volume and market liquidity and more if the Fund has less trading volume and market liquidity. Due to the costs inherent in buying or selling a Fund’s shares, frequent trading may detract significantly from investment returns. Investment in a Fund’s shares may not be advisable for investors who expect to engage in frequent trading.

Shares of a Fund may trade on an exchange at prices at, above or below their most recent NAV, which could result in an investor buying shares of the Fund at a higher price than the Fund’s NAV or selling shares of the Fund at a lower price than the Fund’s NAV. The market prices of Fund shares will fluctuate, sometimes rapidly and materially, in response to changes in the Fund’s NAV, the value of Fund holdings and supply and demand for Fund shares. Although the creation/redemption feature of the Funds generally makes it more likely that Fund shares will trade close to NAV, market volatility, lack of an active trading market for Fund shares, disruptions at market participants (such as Authorized Participants or market makers) and any disruptions in the ordinary functioning of the creation/redemption process may result in Fund shares trading significantly above (at a “premium”) or below (at a “discount”) NAV. Additionally, to the extent a Fund holds securities traded in markets that close at a different time from the Fund’s listing exchange liquidity in such securities may be reduced after the applicable closing times, and during the time when the Fund’s listing exchange is open but after the applicable market closing, fixing or settlement times, bid/ask spreads and the resulting premium or discount to the Fund’s shares’ NAV may widen. You may be unable to sell your shares or may incur significant losses if you transact in Fund shares in these and other circumstances. Neither PIMCO nor the Trust can predict whether Fund shares will trade above, below or at NAV. A Fund’s investment results are based on the Fund’s daily NAV. Investors transacting in Fund shares in the secondary market, where market prices may differ from NAV, may experience investment results that differ from results based on the Fund’s daily NAV. There are various methods by which investors can purchase and sell shares and various orders that may be placed. Investors should consult their financial intermediary before purchasing or selling shares of the Funds.

A Fund has a limited number of intermediaries that act as Authorized Participants, and none of these Authorized Participants are or will be obligated to engage in creation or redemption transactions. To the extent that these intermediaries exit the business or are unable to or choose not to proceed with creation and/or redemption orders with respect to a Fund and no other Authorized Participant is able and willing to create or redeem, shares

18 Prospectus | PIMCO Equity Series

Prospectus

may trade at a discount to NAV and possibly face trading halts and/ or delisting. Additionally, while Fund shares are listed for trading on an exchange, there can be no assurance that active trading markets for Fund shares will be maintained by market makers or Authorized Participants. Decisions by market makers or Authorized Participants to reduce their role or “step away” from these activities in times of market stress may inhibit the effectiveness of the creation/redemption process in maintaining the relationship between the underlying value of a Fund’s holdings and the Fund’s NAV. Such reduced effectiveness could result in the Fund’s shares trading at a discount to its NAV and also in greater than normal intraday bid/ask spreads for the Fund’s shares. Securities that trade outside of a collateralized settlement system may require a longer time to settle than ETF shares, and ETFs that invest in such instruments often require Authorized Participants to post collateral. To the extent a Fund holds such securities, there are a limited number of financial institutions that post collateral as Authorized Participants for certain types of trades.

Equity Risk

Equity securities represent an ownership interest, or the right to acquire an ownership interest, in an issuer. Equity securities also include, among other things, preferred securities, convertible stocks and warrants. The values of equity securities, such as common stocks and preferred securities, may decline due to general market conditions which are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. They may also decline due to factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. Equity securities generally have greater price volatility than fixed income securities. These risks are generally magnified in the case of equity investments in distressed companies.

Credit Risk

A Fund could lose money if the counterparty to a derivatives contract, repurchase agreement or a loan of portfolio securities, is unable or unwilling, or is perceived (whether by market participants, rating agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. The downgrade of the credit of a security held by a Fund may decrease its value. Securities are subject to varying degrees of credit risk, which are often reflected in credit ratings. Measures such as average credit quality may not accurately reflect the true credit risk of a Fund. This is especially the case if the Fund consists of securities with widely varying credit ratings. Therefore, if a Fund has an average credit rating that suggests a certain credit quality, the Fund may in fact be subject to greater credit risk than the average would suggest. This risk is greater to the extent the Fund uses leverage or derivatives in connection with the management of the Fund.

Market Risk

The market price of securities owned by a Fund may go up or down, sometimes rapidly or unpredictably. Securities may decline in value due to factors affecting securities markets generally or particular industries represented in the securities markets. The value of a security may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates, adverse changes to credit markets or adverse investor sentiment generally. The value of a security may also decline due to factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. During a general downturn in the securities markets, multiple asset classes may decline in value simultaneously. Equity securities generally have greater price volatility than fixed income securities. Credit ratings downgrades may also negatively affect securities held by a Fund. Even when markets perform well, there is no assurance that the investments held by a Fund will increase in value along with the broader market.

In addition, market risk includes the risk that geopolitical and other events will disrupt the economy on a national or global level. For instance, war, terrorism, market manipulation, government defaults, government shutdowns, political changes or diplomatic developments, public health emergencies (such as the spread of infectious diseases, pandemics and epidemics) and natural/environmental disasters can all negatively impact the securities markets, which could cause the Funds to lose value. These events could reduce consumer demand or economic output, result in market closures, travel restrictions or quarantines, and significantly adversely impact the economy. The current contentious domestic political environment, as well as political and diplomatic events within the United States and abroad, such as presidential elections in the U.S. or abroad or the U.S. government’s inability at times to agree on a long-term budget and deficit reduction plan, has in the past resulted, and may in the future result, in a government shutdown or otherwise adversely affect the U.S. regulatory landscape, the general market environment and/or investor sentiment, which could have an adverse impact on a Fund’s investments and operations. Additional and/or prolonged U.S. federal government shutdowns may affect investor and consumer confidence and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree. Governmental and quasi-governmental authorities and regulators throughout the world have previously responded to serious economic disruptions with a variety of significant fiscal and monetary policy changes, including but not limited to, direct capital infusions into companies, new monetary programs and dramatically lower interest rates. An unexpected or sudden reversal of these policies, or the ineffectiveness of these policies, could increase volatility in securities markets, which could adversely affect a Fund’s investments. Any market disruptions could also prevent a Fund from executing advantageous investment decisions in a timely manner. Funds that have focused their investments in a region enduring geopolitical

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PIMCO Equity Series

market disruption will face higher risks of loss, although the increasing interconnectivity between global economies and financial markets can lead to events or conditions in one country, region or financial market adversely impacting a different country, region or financial market. Thus, investors should closely monitor current market conditions to determine whether a specific Fund meets their individual financial needs and tolerance for risk.

Current market conditions may pose heightened risks with respect to Funds that invest in fixed income securities. Interest rates in the U.S. are at or near historically low levels. Any interest rate increases in the future could cause the value of any Fund that invests in fixed income securities to decrease. As such, fixed income securities markets may experience heightened levels of interest rate, volatility and liquidity risk. If rising interest rates cause a Fund to lose enough value, the Fund could also face increased shareholder redemptions, which could force the Fund to liquidate investments at disadvantageous times or prices, therefore adversely affecting the Fund and its shareholders.

Exchanges and securities markets may close early, close late or issue trading halts on specific securities or generally, which may result in, among other things, a Fund being unable to buy or sell certain securities or financial instruments at an advantageous time or accurately price its portfolio investments. In addition, a Fund may rely on various third-party sources to calculate its NAV. As a result, a Fund is subject to certain operational risks associated with reliance on service providers and service providers’ data sources. In particular, errors or systems failures and other technological issues may adversely impact the Funds’ calculations of their NAVs, and such NAV calculation issues may result in inaccurately calculated NAVs, delays in NAV calculation and/or the inability to calculate NAVs over extended periods. The Funds may be unable to recover any losses associated with such failures.

Liquidity Risk

The SEC defines liquidity risk as the risk that a Fund could not meet requests to redeem shares issued by the Fund without significant dilution of remaining investors’ interests in the Fund. Liquidity risk exists when particular investments are difficult to purchase or sell. Illiquid investments are investments 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. Illiquid investments may become harder to value, especially in changing markets. A Fund’s investments in illiquid investments may reduce the returns of the Fund because it may be unable to sell the illiquid investments at an advantageous time or price or possibly require a Fund to dispose of other investments at unfavorable times or prices in order to satisfy its obligations, which could prevent the Fund from taking advantage of other investment opportunities. The liquidity of Fund shares may be constrained by the liquidity of the Fund’s portfolio holdings. Relative declines in liquidity of a Fund’s portfolio holdings may result in Authorized Participants being less willing, or unwilling, to transact in Fund shares in the primary market, which could result in Fund shares trading at a premium or discount to Fund NAV and/or at greater bid/ask spreads. Additionally, the market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Such issues may be exacerbated during periods of economic uncertainty.

In such cases, a Fund, due to regulatory limitations on investments in illiquid investments and the difficulty in purchasing and selling such securities or instruments, may be unable to achieve its desired level of exposure to a certain sector. To the extent that a Fund’s principal investment strategies involve securities of companies with smaller market capitalizations, foreign (non-U.S.) securities, derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure to liquidity risk. Finally, liquidity risk also refers to the risk of unusually high redemption requests, redemption requests by certain large shareholders such as institutional investors or asset allocators, or other unusual market conditions that may make it difficult for a Fund to sell investments within the allowable time period to meet redemptions. Meeting such redemption requests could require a Fund to sell securities at reduced prices or under unfavorable conditions, which would reduce the value of the Fund. It may also be the case that other market participants may be attempting to liquidate holdings at the same time as a Fund, causing increased supply in the market and contributing to liquidity risk and downward pricing pressure.

Certain accounts or PIMCO affiliates may from time to time own (beneficially or of record) or control a significant percentage of a Fund’s shares. Redemptions by these shareholders of their holdings in a Fund may impact the Fund’s liquidity and NAV. These redemptions may also force a Fund to sell securities, which may negatively impact the Fund’s brokerage costs.

Issuer Risk

The value of a security may decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods or services, as well as the historical and prospective earnings of the issuer and the value of its assets. A change in the financial condition of a single issuer may affect securities markets as a whole.

Derivatives Risk

Derivatives are financial contracts whose value depends on, or is derived from, the value of an underlying asset, reference rate or index. The various derivative instruments that the Funds may use are referenced under “Characteristics and Risks of Securities and Investment Techniques—Derivatives” in this prospectus and described in more detail under “Investment Objectives and Policies” in the SAI. The Funds typically use derivatives as a substitute for taking a position in the underlying asset, as part of strategies designed to gain exposure to, for example, issuers,

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Prospectus

portions of the yield curve, indexes, sectors, currencies, and/or geographic regions, and/or to reduce exposure to other risks, such as interest rate, credit or currency risk. The Funds may also use derivatives for leverage, in which case their use would involve leveraging risk, and in some cases, may subject a Fund to the potential for unlimited loss. The use of derivatives may cause the Fund’s investment returns to be impacted by the performance of securities the Fund does not own and result in the Fund’s total investment exposure exceeding the value of its portfolio.

A Fund’s use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional investments. Derivatives are subject to a number of risks described elsewhere in this section, such as liquidity risk (which may be heightened for highly-customized derivatives), interest rate risk, market risk, credit risk and management risk, as well as risks arising from changes in applicable requirements. They also involve the risk of improper valuation and the risk that changes in the value of a derivative instrument may not correlate perfectly with the underlying asset, rate or index. By investing in a derivative instrument, the Fund could lose more than the initial amount invested and derivatives may increase the volatility of the Fund, especially in unusual or extreme market conditions. Also, suitable derivative transactions may not be available in all circumstances and there can be no assurance that a Fund will engage in these transactions to reduce exposure to other risks when that would be beneficial or that, if used, such strategies will be successful. In addition, a Fund’s use of derivatives may increase or accelerate the amount of taxes payable by shareholders. Over-the-counter (“OTC”) derivatives are also subject to the risk that a counterparty to the transaction will not fulfill its contractual obligations to the other party, as many of the protections afforded to centrally-cleared derivative transactions might not be available for OTC derivatives. The primary credit risk on derivatives that are exchange-traded or traded through a central clearing counterparty resides with the Fund’s clearing broker, or the clearinghouse.

Participation in the markets for derivative instruments involves investment risks and transaction costs to which a Fund may not be subject absent the use of these strategies. The skills needed to successfully execute derivative strategies may be different from those needed for other types of transactions. If the Fund incorrectly forecasts the value and/or creditworthiness of securities, currencies, interest rates, counterparties or other economic factors involved in a derivative transaction, the Fund might have been in a better position if the Fund had not entered into such derivative transaction. In evaluating the risks and contractual obligations associated with particular derivative instruments, it is important to consider that certain derivative transactions may be modified or terminated only by mutual consent of the Fund and its counterparty. Therefore, it may not be possible for a Fund to modify, terminate, or offset the Fund’s obligations or the Fund’s exposure to the risks associated with a derivative transaction prior to its scheduled termination or maturity date, which may create a possibility of increased volatility and/or decreased liquidity to the Fund. In such case, the Fund may lose money.

Because the markets for certain derivative instruments (including markets located in foreign countries) are relatively new and still developing, appropriate derivative transactions may not be available in all circumstances for risk management or other purposes. Upon the expiration of a particular contract, a Fund may wish to retain its position in the derivative instrument by entering into a similar contract, but may be unable to do so if the counterparty to the original contract is unwilling to enter into the new contract and no other appropriate counterparty can be found. When such markets are unavailable, a Fund will be subject to increased liquidity and investment risk.

When a derivative is used as a hedge against a position that a Fund holds, any loss generated by the derivative generally should be substantially offset by gains on the hedged investment, and vice versa. Although 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 instrument, and there can be no assurance that a Fund’s hedging transactions will be effective.

The regulation of the derivatives markets has increased over the past several years, and additional future regulation of the derivatives markets may make derivatives more costly, may limit the availability or reduce the liquidity of derivatives, or may otherwise adversely affect the value or performance of derivatives. Any such adverse future developments could impair the effectiveness or raise the costs of a Fund’s derivative transactions, impede the employment of the Fund’s derivatives strategies, or adversely affect the Fund’s performance.

For instance, in October 2020, the SEC adopted a final rule related to the use of derivatives, short sales, reverse repurchase agreements and certain other transactions by registered investment companies. In connection with the final rule, the SEC and its staff will rescind and withdraw applicable guidance and relief regarding asset segregation and coverage transactions reflected in the Funds’ asset segregation and cover practices discussed herein. Subject to certain exceptions, and after an eighteen-month transition period, the final rule requires the Funds to trade derivatives and other transactions that create future payment or delivery obligations (except reverse repurchase agreements and similar financing transactions) subject to value-at-risk leverage limits and certain derivatives risk management program and reporting requirements. These requirements may limit the ability of a Fund to invest in derivatives, short sales, reverse repurchase agreements and similar financing transactions, limit the Fund’s ability to employ certain strategies that use these instruments and/or adversely affect the Fund’s performance, efficiency in implementing its strategy, liquidity and/or ability to pursue its investment objectives and may increase the cost of the Fund’s investments and cost of doing business, which could adversely affect investors.

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PIMCO Equity Series

Foreign (Non-U.S.) Investment Risk

Certain Funds may invest in foreign (non-U.S.) securities and may experience more rapid and extreme changes in value than a fund that invests exclusively in securities of U.S. issuers or securities that trade exclusively in U.S. markets. The securities markets of many foreign (non-U.S.) countries are relatively small, with a limited number of companies representing a small number of industries. Additionally, issuers of foreign (non-U.S.) securities are usually not subject to the same degree of regulation as U.S. issuers. Reporting, accounting and auditing standards of foreign countries differ, in some cases significantly, from U.S. standards. Global economies and financial markets are becoming increasingly interconnected, and conditions and events in one country, region or financial market may adversely impact issuers in a different country, region or financial market. Also, nationalization, expropriation or confiscatory taxation, currency blockage, market disruptions, political changes, security suspensions or diplomatic developments could adversely affect a Fund’s investments in a foreign country. In the event of nationalization, expropriation or other confiscation, a Fund could lose its entire investment in foreign (non-U.S.) securities. Adverse conditions in a certain region can adversely affect securities of other countries whose economies appear to be unrelated. To the extent that a Fund invests a significant portion of its assets in a specific geographic region, or in securities denominated in a particular foreign (non-U.S.) currency, the Fund will generally have more exposure to regional economic risks including weather emergencies and natural disasters, associated with foreign (non-U.S.) investments. Foreign (non-U.S.) securities may also be less liquid and more difficult to value than securities of U.S. issuers.

Emerging Markets Risk

Foreign (non-U.S.) investment risk may be particularly high to the extent a Fund invests in emerging market securities. Emerging market securities may present market, credit, currency, liquidity, legal, political, technical and other risks different from, and potentially greater than, the risks of investing in securities and instruments economically tied to developed foreign countries. To the extent a Fund invests in emerging market securities that are economically tied to a particular region, country or group of countries, the Fund may be more sensitive to adverse political or social events affecting that region, country or group of countries. Economic, business, political, or social instability may affect emerging market securities differently, and often more severely, than developed market securities. A Fund that focuses its investments in multiple asset classes of emerging market securities may have a limited ability to mitigate losses in an environment that is adverse to emerging market securities in general. Emerging market securities may also be more volatile, less liquid (particularly during market closures due to local holidays or other reasons) and more difficult to value than securities economically tied to developed foreign countries. The systems and procedures for trading and settlement of securities in emerging markets are less developed and less transparent and transactions may take longer to settle. Emerging market countries typically have less established legal, accounting and financial reporting systems than those in more developed markets, which may reduce the scope or quality of financial information available to investors. Governments in emerging market countries are often less stable and more likely to take extra-legal action with respect to companies, industries, assets, or foreign ownership than those in more developed markets. Moreover, it can be more difficult for investors to bring litigation or enforce judgments against issuers in emerging markets or for U.S. regulators to bring enforcement actions against such issuers. A Fund may also be subject to Emerging Markets Risk if they invest in derivatives or other securities or instruments whose value or return are related to the value or returns of emerging markets securities. Rising interest rates, combined with widening credit spreads, could negatively impact the value of emerging market debt and increase funding costs for foreign issuers. In such a scenario, foreign issuers might not be able to service their debt obligations, the market for emerging market debt could suffer from reduced liquidity, and any investing Funds could lose money. The economy of some emerging markets may be particularly exposed to or affected by a certain industry or sector, and therefore issuers and/or securities of such emerging markets may be more affected by the performance of such industries or sectors.

Currency Risk

If a Fund invests directly in foreign (non-U.S.) currencies or in securities that trade in, and receive revenues in, foreign (non-U.S.) currencies, or in derivatives or other instruments that provide exposure to foreign (non-U.S.) currencies, it will be subject to the risk that those currencies will decline in value relative to the U.S. dollar, or, in the case of hedging positions, that the U.S. dollar will decline in value relative to the currency being hedged.

Currency rates in foreign (non-U.S.) countries may fluctuate significantly over short periods of time for a number of reasons, including changes in interest rates, rates of inflation, balance or payments and governmental surpluses or deficits, intervention (or the failure to intervene) by U.S. or foreign governments, central banks or supranational entities such as the International Monetary Fund, or by the imposition of currency controls or other political developments in the United States or abroad. As a result, a Fund’s investments in foreign currency-denominated securities may reduce the returns of the Fund.

Currency risk may be particularly high to the extent that a Fund invests in foreign (non-U.S.) currencies or engages in foreign currency transactions that are economically tied to emerging market countries. These currency transactions may present market, credit, currency, liquidity, legal, political and other risks different from, or greater than, the risks of investing in developed foreign (non-U.S.) currencies or engaging in foreign currency transactions that are economically tied to developed foreign countries.

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Model Risk

In constructing the Underlying Index of a Fund, the index provider may utilize quantitative models or methodologies that may be proprietary or developed by third-parties. These models are used to help determine the composition of each Underlying Index and may not adequately take into account certain factors, resulting in a decline in the value of the Underlying Index and, therefore, the Fund.

Models rely on accurate market data inputs. If inaccurate market data is entered into a model, the resulting information will be incorrect. In addition, the models used may be predictive in nature and such models may result in an incorrect assessment of future events. The models evaluate securities or securities markets based on certain assumptions concerning the interplay of market factors. The markets or the prices of individual securities may be affected by factors not foreseen in developing the models.

Leveraging Risk

Certain transactions may give rise to a form of leverage. Such transactions may include, among others, reverse repurchase agreements, loans of portfolio securities, and the use of when-issued, delayed delivery or forward commitment transactions. The use of derivatives may also create leveraging risk. In accordance with current federal securities laws, rules and staff positions, the Sub-Adviser will attempt to mitigate the Fund’s leveraging risk by segregating or “earmarking” liquid assets or otherwise covering transactions that may give rise to such risk. The Funds also may be exposed to leveraging risk by borrowing money for investment purposes. Leverage may cause a Fund to liquidate portfolio positions to satisfy its obligations or to meet segregation requirements when it may not be advantageous to do so. Leverage, including borrowing, may cause a Fund to be more volatile than if the Fund had not been leveraged. This is because leverage tends to exaggerate the effect of any increase or decrease in the value of a Fund's portfolio securities. Certain types of leveraging transactions, such as short sales that are not “against the box” (i.e., short sales where the Fund does not hold the security or have the right to acquire it without payment of further consideration), could theoretically be subject to unlimited losses in cases where a Fund, for any reason, is unable to close out the transaction. In addition, to the extent a Fund borrows money, interest costs on such borrowings may not be recovered by any appreciation of the securities purchased with the borrowed amounts and could exceed the Fund’s investment returns, resulting in greater losses. Moreover, to make payments of interest and other loan costs, a Fund may be forced to sell portfolio securities when it is not otherwise advantageous to do so.

Management and Tracking Error Risk

Each Fund is subject to management risk. The Sub-Adviser and each individual portfolio manager will apply investment techniques and risk analysis in making investment decisions for the Funds, but there can be no guarantee that these decisions will produce the desired results. Certain securities or other instruments in which a Fund seeks to invest may not be available in the quantities desired. In addition, regulatory restrictions, actual or potential conflicts of interest or other considerations may restrict or prohibit a Fund’s ability to participate in certain investments. In such circumstances, the Sub-Adviser or the individual portfolio managers may determine to purchase other securities or instruments as substitutes. Such substitute securities or instruments may not perform as intended, which could result in losses to the Fund. Additionally, legislative, regulatory, or tax restrictions, policies or developments may affect the investment techniques available to the Sub-Adviser and each individual portfolio manager in connection with managing the Funds and may also adversely affect the ability of the Funds to achieve their investment objectives. There also can be no assurance that all of the personnel of the Sub-Adviser will continue to be associated with the Sub-Adviser for any length of time. The loss of services of one or more key employees of the Sub-Adviser could have an adverse impact on the Fund’s ability to realize its investment objective.

A Fund may not invest in every component security of its Underlying Index. Imperfect correlation between a Fund’s portfolio and its Underlying Index, asset valuation, timing variances, changes to the Underlying Index and regulatory requirements may cause the Fund’s performance to diverge from the performance of its Underlying Index. Tracking error may also result because a Fund incurs fees and expenses while its Underlying Index does not incur such fees and expenses. Such expenses include the costs of buying and selling securities, such as when a Fund rebalances its portfolio to reflect changes in the composition of the Underlying Index. These expenses may be higher for a Fund investing in foreign (non-U.S.) securities. The performance of a Fund and the Underlying Index may vary due to differences between the Fund’s portfolio and the Underlying Index due to legal restrictions, cost or liquidity restraints. The risk that performance of a Fund and the Underlying Index may vary may be heightened during periods of market volatility or other unusual market conditions. Because an Underlying Index is not subject to the tax diversification requirements to which a Fund must adhere, the Fund may be required to deviate its investments from the securities and relative weightings of its Underlying Index. For tax efficiency purposes, a Fund may sell certain securities to realize losses, which will result in a deviation from its Underlying Index. A Fund may not be fully invested at times either as a result of cash flows into the Fund or reserves of cash held by the Fund to meet redemptions and to pay expenses. In addition, for a Fund that uses a representative sampling approach, this approach may cause the Fund to be less correlated with the return of the Underlying Index than if the Fund held all of the securities in the Underlying Index with the same relative weightings as the Underlying Index.

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PIMCO Equity Series

Indexing Risk

Each Fund uses an indexing approach and may be affected by a general decline in market segments or asset classes relating to its Underlying Index. A Fund invests in securities and instruments included in, or representative of, its Underlying Index regardless of the investment merits of the Underlying Index. Generally, the index provider does not provide any warranty, or accept any liability, with respect to the quality, accuracy, or completeness of either the Underlying Index or its related data. Additionally, errors in the construction or calculation of a Fund’s Underlying Index may occur from time to time, and the index provider may not identify or correct such errors for some period of time or at all. Any such Underlying Index construction or calculation error may adversely impact the Fund, and any gains from such errors will be kept by the Fund and any losses or costs resulting from such errors will be borne by the Fund.

Additionally, unusual market conditions may cause the index provider to postpone a scheduled rebalance or reconstitution, which could cause a Fund’s Underlying Index to vary from its normal or expected composition. This means that, based on market and economic conditions, a Fund’s performance could be lower than funds that may actively shift their portfolio assets to take advantage of market opportunities or to lessen the impact of a market decline or a decline in the value of one or more issuers.

Environmental, Social and Governance Investing Risk

Because the PIMCO RAFI ESG U.S. ETF’s Underlying Index may select or exclude securities of certain issuers for reasons other than performance, there is a risk that the Fund’s performance will differ from funds that track an underlying index that does not utilize an ESG investing strategy. The application of this strategy may affect a Fund’s exposure to certain sectors or types of investments, which could negatively impact a Fund’s performance. ESG investing is qualitative and subjective by nature, and there is no guarantee that the factors utilized by the Index Provider or any judgment exercised by the Index Provider in constructing the Underlying Index will reflect the opinions of any particular investor. In evaluating an issuer, the Index Provider is dependent upon information and data obtained through voluntary or third-party reporting that may be incomplete, inaccurate or unavailable, which could cause the Index Provider to incorrectly assess an issuer’s business practices with respect to the environment, social responsibility and corporate governance. There can be no assurance that the ESG strategy or techniques employed by the Index Provider in constructing the Underlying Index will be successful. Past performance is not a guarantee or reliable indicator of future results.

Disclosure of Portfolio Holdings

Please see “Disclosure of Portfolio Holdings” in the SAI for information about the availability of the complete schedule of each Fund’s holdings.

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Prospectus

Management of the Funds

Investment Manager

PIMCO serves as the investment manager for the Funds. Subject to the supervision of the Board of Trustees, PIMCO is responsible for managing the investment activities of the Funds and the Funds’ business affairs and other administrative matters.

PIMCO is located at 650 Newport Center Drive, Newport Beach, CA 92660. Organized in 1971, PIMCO provides investment management and advisory services to private accounts of institutional and individual clients and to mutual funds. As of September 30, 2021, PIMCO had approximately $2.20 trillion in assets under management.

Sub-Adviser

PIMCO has engaged Parametric Portfolio Associates LLC (“Parametric”), a Delaware limited liability company, to serve as sub-adviser to each Fund. Parametric was organized in 1987 and is located at 800 Fifth Avenue, Suite 2800, Seattle, WA 98104. As sub-adviser to the Funds, Parametric is responsible for providing, subject to the supervision of PIMCO, investment advisory services to the Funds, including execution of all portfolio transactions on behalf of the Funds necessary to invest the assets of each Fund in the component securities of its Underlying Index.

Please see the SAI for additional information about the services provided by PIMCO and Parametric.

Management Fees

Each Fund pays PIMCO fees in return for providing investment advisory and supervisory and administrative services under what is essentially an all-in fee structure. For the fiscal year ended June 30, 2021, the Funds paid monthly Management Fees to PIMCO at the following annual rates (stated as a percentage of the average daily net assets of the Fund taken separately):

Fund Name	Management Fees
PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF	0.49%
PIMCO RAFI Dynamic Multi-Factor International Equity ETF	0.39%
PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF	0.29%
PIMCO RAFI ESG U.S. ETF	0.29%

In addition to providing investment advisory services, PIMCO provides or procures supervisory and administrative services for shareholders and also bears the costs of various third-party services required by the Funds, including audit, custodial, portfolio accounting, legal, transfer agency and printing costs. The Funds bear other expenses which are not covered under the management fee which may vary and affect the total level of expenses paid by the shareholders, such as taxes and governmental fees, brokerage fees, commissions and other transaction expenses, costs of borrowing money, including interest expenses, securities lending expenses, extraordinary expenses (such as litigation and indemnification expenses) and fees and expenses of the Trust’s Independent Trustees and their counsel. PIMCO generally earns a profit on the management fee paid by the Funds. Also, under the terms of the investment management agreement, PIMCO, and not Fund shareholders, would benefit from any price decreases in third-party services, including decreases resulting from an increase in net assets.

A discussion of the basis for the Board of Trustees’ approval of the Funds’ investment management agreement and sub-advisory agreement is available in the Funds’ semi-annual report to shareholders for the fiscal half-year ended December 31, 2020 and the Funds' Annual Report to shareholders for the fiscal year ended June 30, 2021.

Expense Limitation Agreement

PIMCO has contractually agreed, through October 31, 2022, to waive its Management Fee or reimburse each Fund, to the extent that the Fund’s organizational expenses, pro rata share of expenses related to obtaining or maintaining a Legal Entity Identifier and pro rata share of Trustee fees exceed 0.0049% (the “ Expense Limit”) (calculated as a percentage of the Fund’s average daily net assets). This Expense Limitation Agreement will automatically renew for one-year terms unless PIMCO provides written notice to the Trust at least 30 days prior to the end of the then current term. In any month in which the investment management agreement is in effect, PIMCO is entitled to reimbursement by each Fund of any portion of the Management Fee waived or reimbursed as set forth above (the “ Reimbursement Amount”) during the previous thirty-six months from the time of the waiver, provided that such amount paid to PIMCO will not: 1) together with any organizational expenses, pro rata share of expenses related to obtaining or maintaining a Legal Entity Identifier and pro rata Trustee fees, exceed, for such month, the Expense Limit (or the amount of the expense limit in place at the time the amount being recouped was originally waived if lower than the Expense Limit); 2) exceed the total Reimbursement Amount; or 3) include any amounts previously reimbursed to PIMCO.

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PIMCO Equity Series

Individual Portfolio Manager

The following individual has primary responsibility for managing each of the noted Funds.

Fund	Portfolio Manager	Since	Recent Professional Experience
PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF	Thomas Seto	08/17*	Head of Investment Management and Managing Director, Parametric Portfolio Associates LLC. He is a member of the Executive Committee of Parametric. Prior to joining Parametric in 1998, he served as the Head of U.S. Equity Index Investments at Barclays Global Investors. He earned an MBA in Finance from the University of Chicago’s Booth School of Business, and a B.S. in Electrical Engineering from the University of Washington.
PIMCO RAFI Dynamic Multi-Factor International Equity ETF		08/17*
PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF		08/17*
PIMCO RAFI ESG U.S. ETF		12/19*

Inception of the Fund.

Please see the SAI for additional information about other accounts managed by the portfolio manager, the portfolio manager's compensation and the portfolio manager's ownership of shares of the Funds.

The Trustees are responsible generally for overseeing the management of the Trust. The Trustees authorize the Trust to enter into service agreements with the investment manager, the Distributor (as defined below), and other service providers in order to provide, and in some cases authorize service providers to procure through other parties, necessary or desirable services on behalf of the Trust and the Funds. Shareholders are not parties to or third-party beneficiaries of such service agreements. Neither this prospectus nor summary prospectus, the Trust’s SAI, any contracts filed as exhibits to the Trust’s registration statement, nor any other communications, disclosure documents or regulatory filings from or on behalf of the Trust or a Fund creates a contract between or among any shareholder of a Fund, on the one hand, and the Trust, a Fund, a service provider to the Trust or a Fund, and/or the Trustees or officers of the Trust, on the other hand. The Trustees (or the Trust and its officers, service providers or other delegates acting under authority of the Trustees) may amend this, or use a new prospectus, summary prospectus or SAI with respect to a Fund or the Trust, and/or amend, file and/or issue any other communications, disclosure documents or regulatory filings, and may amend or enter into any contracts to which the Trust or a Fund is a party, and interpret the investment objective(s), policies, restrictions and contractual provisions applicable to any Fund, without shareholder input or approval, except in circumstances in which shareholder approval is specifically required by law (such as changes to fundamental investment policies) or where a shareholder approval requirement is specifically disclosed in the Trust’s then-current prospectus or SAI.

Distributor

The Trust’s Distributor is PIMCO Investments LLC (the “Distributor”). The Distributor, located at 1633 Broadway, New York, NY 10019, is a broker-dealer registered with the SEC. The Distributor distributes Creation Units for the Funds and does not maintain a secondary market in shares of the Funds.

Distribution and Servicing Plan

The Trust has adopted a Distribution and Servicing Plan (the “12b-1 Plan”) for shares of the Funds pursuant to Rule 12b-1 under the Investment Company Act of 1940, as amended (the “1940 Act”). The 12b-1 Plan permits compensation in connection with the distribution and marketing of Fund shares and/or the provision of certain shareholder services. The 12b-1 Plan permits the Fund to pay compensation at an annual rate of up to 0.25% of the Fund’s average daily net assets. However, the Board of Trustees has determined not to authorize payment of a 12b-1 Plan fee at this time.

The 12b-1 fee may only be imposed or increased when the Board of Trustees determines that it is in the best interests of shareholders to do so. Because these fees are paid out of the Fund’s assets on an ongoing basis, to the extent that a fee is authorized, over time they will increase the cost of an investment in the Fund. The 12b-1 Plan fee may cost an investor more than other types of sales charges.

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Prospectus

Payments to Broker-Dealers and Other Financial Intermediaries

PIMCO or the Distributor (for purposes of this subsection only, collectively, “PIMCO”) makes payments to broker-dealers or other financial intermediaries (each, an “Intermediary”) related to activities that are designed to make registered representatives, other professionals and individual investors more knowledgeable about the Funds or for other activities, such as participation in marketing activities and presentations, educational training programs, the support of technology platforms and/or reporting systems. PIMCO also makes payments to Intermediaries for certain printing, publishing and mailing costs associated with the Funds or materials relating to ETFs in general. In addition, PIMCO makes payments to Intermediaries that make Fund shares available to their clients, including on no transaction fee platforms or for otherwise promoting the sale and distribution of the Funds. Such payments, which may be significant to the Intermediary, are not made by a Fund. Rather, such payments are made by PIMCO from its own resources, which may come directly or indirectly in part from management fees paid by the Funds. Payments of this type are sometimes referred to as marketing support or revenue-sharing payments. Such payments may include the reimbursement of ticket charges and revenue sharing tied to assets under management. An Intermediary may make decisions about which investment options it recommends or makes available, or the level of services provided, to its customers based on the marketing support payments it is eligible to receive. Therefore, such payments to an Intermediary create conflicts of interest between the Intermediary and its customers and may cause the Intermediary to recommend a Fund over another investment. More information regarding these payments is contained in the SAI. A shareholder should contact his or her Intermediary’s salesperson or other investment professional for more information regarding any such payments the Intermediary firm may receive from PIMCO.

Buying and Selling Shares

Shares of the Funds are listed for trading on a national securities exchange during the trading day. Each Fund’s primary listing exchange is NYSE Arca. Shares can be bought and sold throughout the trading day like shares of other publicly traded companies. However, there can be no guarantee that an active trading market will develop or be maintained, or that the Fund shares listing will continue or remain unchanged. The Trust does not impose any minimum investment for shares of a Fund purchased on an exchange. Buying or selling a Fund’s shares involves certain costs that apply to all securities transactions. When buying or selling shares of a Fund through a financial intermediary, you may incur a brokerage commission or other charges determined by your financial intermediary. Due to these brokerage costs, if any, frequent trading may detract significantly from investment returns. In addition, you may also incur the cost of the spread (the difference between the bid price and the ask price). The commission is frequently a fixed amount and may be a significant cost for investors seeking to buy or sell small amounts of shares. The spread varies over time for shares of a Fund based on its

trading volume and market liquidity, and is generally less if the Fund has more trading volume and market liquidity and more if the Fund has less trading volume and market liquidity.

Shares of a Fund may be acquired through the Distributor or redeemed directly with the Fund only in Creation Units or multiples thereof, as discussed in the “Creations and Redemptions” section of the SAI. Once created, shares of a Fund generally trade in the secondary market in amounts less than a Creation Unit.

The Trust’s Board of Trustees has not adopted a policy of monitoring for frequent purchases and redemptions of Fund shares (“frequent trading”) that appear to attempt to take advantage of potential arbitrage opportunities presented by a lag between a change in the value of a Fund’s portfolio securities after the close of the primary markets for the Fund’s portfolio securities and the reflection of that change in the Fund’s NAV (“market timing”). The Trust believes this is appropriate because an ETF, such as each Fund, is intended to be attractive to arbitrageurs, as trading activity is critical to ensuring that the market price of Fund shares remains at or close to NAV. Since each Fund issues and redeems Creation Units at NAV plus applicable transaction fees, and each Fund’s shares may be purchased and sold on NYSE Arca at prevailing market prices, the risks of frequent trading are limited.

New York Stock Exchange (“NYSE”) is open for trading Monday through Friday and is closed on the following holidays: New Year’s Day, Martin Luther King, Jr. Day, Presidents’ Day, Good Friday, Memorial Day, Independence Day, Labor Day, Thanksgiving Day and Christmas Day.

A “Business Day” with respect to the Funds is each day NYSE is open. Orders from Authorized Participants to create or redeem Creation Units will only be accepted on a Business Day. On days when NYSE closes earlier than normal, a Fund may require orders to create or redeem Creation Units to be placed earlier in the day. See the SAI for more information.

Section 12(d)(1) of the 1940 Act restricts investments by registered investment companies and companies relying on Sections 3(c)(1) or 3(c)(7) of the 1940 Act in the securities of other investment companies. Registered investment companies are permitted to invest in the Funds beyond the limits set forth in Section 12(d)(1), subject to certain terms and conditions set forth in an SEC exemptive order issued to PIMCO and the Trust, including that such investment companies enter into an agreement with the Trust.

The Trust typically does not offer or sell its shares to non-U.S. resident Authorized Participants. For purposes of this policy, a U.S. resident Authorized Participant is defined as an Authorized Participant that has a U.S. address of record at the time of sale.

Book Entry

Shares of a Fund are held in book-entry form, which means that no stock certificates are issued. The Depository Trust Company (“DTC”) or its nominee is the record owner of all outstanding shares of the Funds and is recognized as the owner of all shares for all purposes.

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Investors owning shares of a Fund are beneficial owners as shown on the records of DTC or its participants. DTC serves as the securities depository for shares of the Funds. DTC participants include securities brokers and dealers, banks, trust companies, clearing corporations and other institutions that directly or indirectly maintain a custodial relationship with DTC. As a beneficial owner of shares, you are not entitled to receive physical delivery of stock certificates or to have shares registered in your name, and you are not considered a registered owner of shares. Therefore, to exercise any right as an owner of shares, you must rely upon the procedures of DTC and its participants. These procedures are the same as those that apply to any other exchange-traded securities that you hold in book-entry or “street name” form.

Share Prices

The trading prices of a Fund’s shares in the secondary market generally differ from the Fund’s daily NAV per share and are affected by market forces such as supply and demand of Fund shares and the underlying securities and instruments held by the Fund, economic conditions and other factors.

Information regarding the intraday indicative value (“IIV”) of a Fund may be disseminated every 15 seconds throughout the trading day by the national securities exchange on which the Fund’s shares are primarily listed or by market data vendors or other information providers. The IIV is based on the current market value of the securities and/or cash included in a Fund’s IIV basket. The IIV does not necessarily reflect the precise composition of the current portfolio of securities and instruments held by a Fund at a particular point in time or the best possible valuation of the current portfolio. Unlike a Fund’s NAV, the IIV may not reflect estimated accrued interest, dividends and other income, or Fund expenses. Therefore, the IIV should not be viewed as a “real-time” update of the NAV, which is computed only once a day. The IIV is generally determined by using both current market quotations and/or price quotations obtained from broker-dealers that may trade in the portfolio securities and instruments included in a Fund’s IIV basket. The quotations and/or valuations of certain Fund holdings may not be updated during U.S. trading hours if such holdings do not trade in the United States. The Fund is not involved in, or responsible for, the calculation or dissemination of the IIV and makes no representation or warranty as to its accuracy. An inaccuracy in the IIV could result from various factors, including the difficulty of pricing portfolio instruments on an intraday basis.

Premiums and Discounts

There may be differences between the daily market prices on secondary markets for shares of a Fund and the Fund’s NAV. NAV is the price per share at which the Fund issues and redeems shares. See “How Net Asset Value Is Determined” below. A Fund’s market price may be at, above or below its NAV. The NAV of a Fund will fluctuate with changes in the market value of its portfolio holdings. The market price of a Fund will fluctuate in accordance with changes in its NAV, as well as market supply and demand. Information regarding a Fund’s NAV and market price can be found at https://www.pimco.com/en-us/investments/etf.

Premiums or discounts are the differences (expressed as a percentage) between the NAV and the market price of a Fund on a given day, generally at the time the NAV is calculated. A premium is the amount that a Fund is trading above the reported NAV, expressed as a percentage of the NAV. A discount is the amount that a Fund is trading below the reported NAV, expressed as a percentage of the NAV. A discount or premium could be significant. Information regarding the frequency of daily premiums or discounts, generally at the time the NAV is calculated, can be found at www.pimcoetfs.com.

Expenses

An index is a statistical composite that tracks a specified financial market, sector or other set of securities specified by the index provider. Unlike a Fund, an index does not actually hold a portfolio of securities and therefore does not incur the expenses incurred by the Fund. These expenses negatively impact the performance of the Fund. Also, index returns do not include brokerage commissions that may be payable on secondary market transactions. If brokerage commissions were included, index returns would be lower. The index’s returns do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or the redemption or sale of Fund shares. The investment return and principal value of shares of a Fund will vary with changes in market conditions. Shares of a Fund may be worth more or less than their original cost when they are redeemed or sold in the market.

Request for Multiple Copies of Shareholder Documents

To reduce expenses, it is intended that only one copy of the Funds’ prospectus and each annual and semi-annual report, when available, will be mailed to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please contact the financial intermediary through which you hold your shares.

How Net Asset Value Is Determined

The NAV of a Fund’s shares is determined by dividing the total value of a Fund’s portfolio investments and other assets attributable to that Fund, less any liabilities, by the total number of shares outstanding of that Fund.

On each day that the NYSE is open, Fund shares are ordinarily valued as of the close of the regular trading (“NYSE Close”). Information that becomes known to the Funds or their agents after the time as of which NAV has been calculated on a particular day will not generally be used to retroactively adjust the price of a security or the NAV determined earlier that day. If regular trading on the NYSE closes earlier than scheduled, each Fund reserves the right to either (i) calculate its NAV as of the earlier closing time or (ii) calculate its NAV as of the normally scheduled close of regular trading on the NYSE for that day. Each Fund generally does not calculate its NAV on days during which the NYSE is closed. However, if the NYSE is closed on a day it would normally be open for business, each Fund reserves the right to calculate its NAV as of the normally scheduled close of regular trading on the NYSE for that day or such other time that the Fund may determine.

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Prospectus

For purposes of calculating NAV, portfolio securities and other assets for which market quotes are readily available are valued at market value. Market value is generally determined on the basis of official closing prices or the last reported sales prices, or if no sales are reported, based on quotes obtained from established market makers or prices (including evaluated prices) supplied by the Funds' approved pricing services, quotation reporting systems and other third-party sources (together, “Pricing Services”). The Funds will normally use pricing data for domestic equity securities received shortly after the NYSE Close and do not normally take into account trading, clearances or settlements that take place after the NYSE Close. If market value pricing is used, a foreign (non-U.S.) equity security traded on a foreign exchange or on more than one exchange is typically valued using pricing information from the exchange considered by PIMCO to be the primary exchange. A foreign (non-U.S.) equity security will be valued as of the close of trading on the foreign exchange, or the NYSE Close, if the NYSE Close occurs before the end of trading on the foreign exchange. Domestic and foreign (non-U.S.) fixed income securities, non-exchange-traded derivatives, and equity options are normally valued on the basis of quotes obtained from brokers and dealers or Pricing Services using data reflecting the earlier closing of the principal markets for those securities. Prices obtained from Pricing Services may be based on, among other things, information provided by market makers or estimates of market values obtained from yield data relating to investments or securities with similar characteristics. Certain fixed income securities purchased on a delayed-delivery basis are marked to market daily until settlement at the forward settlement date. Exchange-traded options, except equity options, futures and options on futures are valued at the settlement price determined by the relevant exchange. Swap agreements are valued on the basis of bid quotes obtained from brokers and dealers or market-based prices supplied by Pricing Services or other pricing sources. With respect to any portion of a Fund’s assets that are invested in one or more open-end management investment companies (other than ETFs), a Fund’s NAV will be calculated based on the NAVs of such investments.

If a foreign (non-U.S.) equity security’s value has materially changed after the close of the security’s primary exchange or principal market but before the NYSE Close, the security may be valued at fair value based on procedures established and approved by the Board of Trustees. Foreign (non-U.S.) equity securities that do not trade when the NYSE is open are also valued at fair value. With respect to foreign (non-U.S.) equity securities, the Fund may determine the fair value of investments based on information provided by Pricing Services and other third-party vendors, which may recommend fair value or adjustments with reference to other securities, indexes or assets. In considering whether fair valuation is required and in determining fair values, the Fund may, among other things, consider significant events (which may be considered to include changes in the value of U.S. securities or securities indexes) that occur after the close of the relevant market and before the NYSE Close. A Fund may utilize modeling tools provided by third-party vendors to determine fair values of non-U.S. securities. For these purposes, any movement in the applicable reference index or instrument (“zero trigger”) between the earlier close of the applicable foreign

market and the NYSE Close may be deemed to be a significant event, prompting the application of the pricing model (effectively resulting in daily fair valuations). Foreign (non-U.S.) exchanges may permit trading in foreign (non-U.S.) equity securities on days when the Trust is not open for business, which may result in a Fund’s portfolio investments being affected when you are unable to buy or sell shares.

Investments valued in currencies other than the U.S. dollar are converted to the U.S. dollar using exchange rates obtained from Pricing Services. As a result, the value of such investments, and in turn, the NAV of the Fund’s shares may be affected by changes in the value of currencies in relation to the U.S. dollar. The value of investments traded in markets outside the United States or denominated in currencies other than the U.S. dollar may be affected significantly on a day that the Trust is not open for business. As a result, to the extent that a Fund holds foreign (non-U.S.) investments, the value of those investments may change at times when shareholders are unable to buy or sell shares and the value of such investments will be reflected in the Fund’s next calculated NAV.

Investments for which market quotes or market based valuations are not readily available are valued at fair value as determined in good faith by the Board of Trustees or persons acting at their direction. The Board of Trustees has adopted methods for valuing securities and other assets in circumstances where market quotes are not readily available, and has delegated to PIMCO the responsibility for applying the fair valuation methods. In the event that market quotes or market based valuations are not readily available, and the security or asset cannot be valued pursuant to a Board approved valuation method, the value of the security or asset will be determined in good faith by the Valuation Oversight Committee of the Board of Trustees, generally based on recommendations provided by PIMCO. Market quotes are considered not readily available in circumstances where there is an absence of current or reliable market-based data (e.g., trade information, bid/ask information, broker quotes, Pricing Services’ prices), including where events occur after the close of the relevant market, but prior to the NYSE Close, that materially affect the values of the Fund’s securities or assets. In addition, market quotes are considered not readily available when, due to extraordinary circumstances, the exchanges or markets on which the securities trade do not open for trading for the entire day and no other market prices are available. The Board of Trustees has delegated to PIMCO the responsibility for monitoring significant events that may materially affect the values of the Fund’s securities or assets and for determining whether the value of the applicable securities or assets should be reevaluated in light of such significant events.

When the Fund uses fair valuation to determine the value of a portfolio security or other asset for purposes of calculating its NAV, such investments, securities will not be priced on the basis of quotes from the primary market in which they are traded, but rather may be priced by another method that the Board of Trustees or persons acting at their direction believe reflects fair value. Fair valuation may require subjective determinations about the value of a security. While the Trust’s policy is intended to result in a calculation of the Fund’s NAV that fairly reflects security values as of the time of pricing, the Trust cannot ensure that fair

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values determined by the Board of Trustees or persons acting at their direction would accurately reflect the price that a Fund could obtain for a security if it were to dispose of that security as of the time of pricing (for instance, in a forced or distressed sale). The prices used by the Fund may differ from the value that would be realized if the securities were sold. In addition, fair value pricing could result in a difference between the prices used to calculate a Fund’s NAV and the prices used by such Fund’s Underlying Index. This may adversely affect a Fund’s ability to track its Underlying Index.

Fund Distributions

Each Fund distributes substantially all of its net investment income to shareholders in the form of dividends. The Funds intend to declare and distribute income dividends quarterly to shareholders of record.

In addition, each Fund distributes any net capital gains earned from the sale of portfolio securities to shareholders no less frequently than annually. Net short-term capital gains may be paid more frequently. Dividend payments are made through DTC participants and indirect participants to beneficial owners then of record with proceeds received from the Funds.

No dividend reinvestment service is provided by the Trust. Financial intermediaries may make available the DTC book-entry Dividend Reinvestment Service for use by beneficial owners of Fund shares for reinvestment of their dividend distributions. Beneficial owners should contact their financial intermediary to determine the availability and costs of the service and the details of participation therein. Financial intermediaries may require beneficial owners to adhere to specific procedures and timetables. If this service is available and used, dividend distributions of both income and net capital gains will be automatically reinvested in additional whole shares of a Fund purchased in the secondary market.

Tax Consequences

The following information is meant as a general summary for U.S. taxpayers. Please see the SAI for additional information. You should rely on your own tax adviser for advice about the particular federal, state and local tax consequences to you of investing in any Fund.

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Taxes on Fund Distributions. If you are subject to U.S. federal income tax, you will be subject to tax on taxable Fund distributions. For federal income tax purposes, taxable Fund distributions will be taxable to you as either ordinary income or capital gains.

Fund taxable dividends (i.e., distributions of investment income) are generally taxable to you as ordinary income. Federal taxes on Fund distributions of gains are determined by how long a Fund owned the investments that generated the gains, rather than how long you have owned your shares. Distributions of gains from investments that the Fund owned for more than one year will generally be taxable to you as long-term capital gains. Distributions of gains from investments that the Fund owned for one year or less, including income from securities lending, will generally be taxable to you as ordinary income.

The tax treatment of income, gains and losses attributable to foreign currencies (and derivatives on such currencies), and various other special tax rules applicable to certain financial transactions and instruments could affect the amount, timing and character of the Fund’s distributions. In some cases, these tax rules could also result in a retroactive change in the tax character of prior distributions and may also possibly cause all, or a portion, of prior distributions to be reclassified as returns of capital for tax purposes. See “Returns of Capital” below.

Fund distributions are taxable to you even if they are paid from income or gains earned by a Fund prior to your investment and thus were included in the price you paid for your shares. For example, if you purchase shares on or just before the record date of a Fund distribution, you will pay full price for the shares and may receive a portion of your investment back as a taxable distribution.

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Taxes When You Sell Your Shares. Any gain resulting from the sale of Fund shares will generally be subject to federal income tax. Currently, any capital gain or loss realized upon a sale of Fund shares is generally treated as a long-term gain or loss if the shares have been held for more than one year. Any capital gain or loss realized upon a sale of Fund shares held for one year or less is generally treated as short-term gain or loss, except that any capital loss on the sale of shares held for six months or less is treated as long-term capital loss to the extent that capital gain dividends were paid with respect to such shares.

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Returns of Capital. If a Fund’s distributions exceed its taxable income and capital gains realized during a taxable year, all or a portion of the distributions made in the same taxable year may be recharacterized as a return of capital to shareholders. A return of capital distribution will generally not be taxable, but will reduce each shareholder’s cost basis in the Fund and result in a higher reported capital gain or lower reported capital loss when those shares on which the distribution was received are sold.

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Medicare Tax. An additional 3.8% Medicare tax is imposed on certain net investment income (including ordinary dividends and capital gain distributions received from a Fund and net gains from redemptions or other taxable dispositions of Fund shares) of U.S. individuals, estates and trusts to the extent that such person’s “modified adjusted gross income” (in the case of an individual) or “adjusted gross income” (in the case of an estate or trust) exceeds certain threshold amounts.

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Important Tax Reporting Considerations. The Internal Revenue Code of 1986 requires reporting of adjusted cost basis information for covered securities, which generally include shares of a regulated investment company acquired after January 1, 2012, to the Internal Revenue Service (“IRS”) and to taxpayers. Shareholders should contact their financial intermediaries with respect to reporting of cost basis and available elections for their accounts.

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Backup Withholding. Shareholders may be subject to U.S. federal income tax withholding with respect to distributions

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Prospectus

payable to shareholders if they fail to provide their correct taxpayer identification number or to make required certifications, or if they have been notified by the IRS that they are subject to backup withholding. Backup withholding is not an additional tax. Any amounts withheld may be credited against U.S. federal income tax liability.

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Foreign Withholding Taxes. A Fund may be subject to foreign withholding or other foreign taxes, which in some cases can be significant on any income or gain from investments in foreign securities. In that case, the Fund’s total return on those securities would be decreased. Although in some cases the Fund may be able to apply for a refund of a portion of such taxes, the ability to successfully obtain such a refund may be uncertain. Each Fund may generally deduct these taxes in computing its taxable income. Rather than deducting these foreign taxes, a Fund that invests more than 50% of its assets in the stock or securities of foreign corporations or foreign governments at the end of its taxable year may make an election to treat a proportionate amount of eligible foreign taxes as constituting a taxable distribution to each shareholder, which would, subject to certain limitations, generally allow the shareholder to either (i) credit that proportionate amount of taxes against U.S. Federal income tax liability as a foreign tax credit or (ii) take that amount as an itemized deduction.

Foreign shareholders may be subject to U.S. tax withholding of 30% (or lower applicable treaty rate) on distributions by a Fund. Additionally, the Funds are required to withhold U.S. tax (at a 30% rate) on payments of taxable dividends made to certain non-U.S. entities that fail to comply (or are deemed noncompliant) with extensive reporting and withholding requirements designed to inform the U.S. Department of the Treasury of U.S.-owned foreign investment accounts. Shareholders may be requested to provide additional information to enable the Funds to determine whether withholding is required.

This “Tax Consequences” section relates only to federal income tax; the consequences under other tax laws may differ. Shareholders should consult their tax advisors as to the possible application of foreign, state and local income tax laws to Fund dividends and capital distributions. Please see “Taxation” in the SAI for additional information regarding the tax aspects of investing in the Funds.

Characteristics and Risks of Securities and Investment Techniques

This section provides additional information about some of the principal investments and related risks of the Funds described under “Fund Summaries” and “Description of Principal Risks” above. It also describes characteristics and risks of additional securities and investment techniques that may be used by the Funds from time to time.

Most of these securities and investment techniques described herein are discretionary, which means that the Sub-Adviser can decide whether to use them or not. This prospectus does not attempt to disclose all of the various types of securities and investment techniques that may be used by the Funds. As with any fund, investors in the Funds rely on the

professional investment judgment and skill of the Sub-Adviser and the individual portfolio manager. Please see “Investment Objectives and Policies” in the SAI for more detailed information about the securities and investment techniques described in this section and about other strategies and techniques that may be used by the Funds.

Investors should be aware that the investments made by a Fund and the results achieved by a Fund at any given time are not expected to be the same as those made by other funds for which PIMCO or the Sub-Adviser acts as investment adviser, including funds with names, investment objectives and policies similar to a Fund. This may be attributable to a wide variety of factors, including, but not limited to, the use of a different portfolio management team or strategy, when a particular fund commenced operations or the size of a particular fund, in each case as compared to other similar funds. Significant purchases and redemptions of its Creation Units may adversely impact a Fund’s portfolio management.

For example, a Fund may be forced to sell a comparatively large portion of its portfolio to meet significant Creation Unit redemptions for cash, or hold a comparatively large portion of its portfolio in cash due to significant Creation Unit purchases for cash, in each case when the Fund otherwise would not seek to do so. Such transactions may cause Funds to make investment decisions at inopportune times or prices or miss attractive investment opportunities. Such transactions may also accelerate the realization of taxable income if sales of securities resulted in gains and the Fund redeems Creation Units for cash, or otherwise cause a Fund to perform differently than intended. Similarly, significant purchases of its Creation Units for cash may adversely affect a Fund’s performance to the extent the Fund is delayed in investing new cash and, as a result, holds a proportionally larger cash position than under ordinary circumstances. While such risks may apply to Funds of any size, such risks are heightened in Funds with fewer assets under management. In addition, new Funds may not be able to fully implement their investment strategy immediately upon commencing investment operations, which could reduce investment performance.

Certain PIMCO-advised funds (the “PIMCO Funds of Funds”) invest substantially all or a significant portion of their assets in other PIMCO-advised funds, including the Funds (“Underlying PIMCO Funds”). In some cases, the PIMCO Funds of Funds and certain funds managed by investment advisers affiliated with PIMCO (“Affiliated Funds of Funds”) may be the predominant or sole shareholders of a particular Underlying PIMCO Fund. Investment decisions made with respect to the PIMCO Funds of Funds and Affiliated Funds of Funds could, under certain circumstances, negatively impact the Underlying PIMCO Funds with respect to the expenses and investment performance of the Underlying PIMCO Funds. For instance, large purchases or redemptions of exchange-traded shares of a Fund by the PIMCO Funds of Funds and Affiliated Funds of Funds, whether as part of a reallocation or rebalancing strategy or otherwise, may indirectly result in the Underlying PIMCO Fund having to sell securities or invest cash when it otherwise would not do so. Such transactions could increase an Underlying PIMCO Fund’s transaction costs and accelerate the realization of taxable income if sales of securities resulted in gains and

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the Fund redeems Creation Units for cash. Additionally, as the PIMCO Funds of Funds and Affiliated Funds of Funds may invest substantially all or a significant portion of their assets in Underlying PIMCO Funds, the Underlying PIMCO Funds may not acquire securities of other registered open-end investment companies in reliance on Section 12(d)(1)(F) or Section 12(d)(1)(G) of the 1940 Act, thus limiting the Underlying PIMCO Funds’ investment flexibility.

Investment Selection

Each of the PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF, PIMCO RAFI Dynamic Multi-Factor International Equity ETF and PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF seeks to track the investment results of such Fund’s Underlying Index. The PIMCO RAFI ESG U.S. ETF seeks to provide total return that closely corresponds, before fees and expenses, to the total return of such Fund’s Underlying Index. In selecting securities and instruments for the PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF and PIMCO RAFI ESG U.S. ETF, the Sub-Adviser is expected to invest in the same securities as such Fund’s respective Underlying Index and in approximately the same proportions. However, in some circumstances it may not be possible or practicable to invest in the same securities as such Fund’s Underlying Index and in approximately the same proportions, in which case the Sub-Adviser may employ a representative sampling strategy, as further described in the PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF’s and PIMCO RAFI ESG U.S. ETF’s Fund Summaries. In selecting securities and instruments for the PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF and PIMCO RAFI Dynamic Multi-Factor International Equity ETF, the Sub-Adviser employs a representative sampling strategy, as further described in each Fund’s Fund Summary.

When using a representative sampling strategy, the Sub-Adviser may invest in a combination of component securities and other investments, or in component securities but in different proportions as compared to the weighting of the Underlying Index, such that the portfolio effectively provides exposure to the Underlying Index. The Sub-Adviser attempts to match the risk and return characteristics of a Fund’s portfolio to the risk and return characteristics of a Fund’s Underlying Index. The Sub-Adviser decomposes the portfolio risk of the Underlying Index into common factor risk (such as country membership, industry membership, and current fundamental ratios) and idiosyncratic risk, using a fundamental multiple factor equity risk model. The Sub-Adviser constructs a Fund’s portfolio to minimize active risk (tracking error) with respect to the Fund’s Underlying Index, as measured by the multiple-factor risk model. Additionally, the Sub-Adviser constrains common factor exposures and individual index relative security weights, to explicitly neutralize the Fund’s portfolio risk exposures relative to the Fund’s Underlying Index.

There are many potential benefits to using a representative sampling strategy with respect to a Fund. For example, the Sub-Adviser can avoid securities that are relatively expensive (i.e., securities that trade at perceived higher prices) but have the same relative risk, value, duration and other characteristics as less expensive securities. In addition, the use of sampling techniques permit the Sub-Adviser to exclude securities that it believes will soon be deleted from the Underlying Index. Furthermore,

the Sub-Adviser can develop a basket of component securities that is easier to construct and less expensive to trade, thereby potentially improving arbitrage opportunities.

Securities and instruments of a company are assigned to a country based on the company’s country of primary listing, domicile, and incorporation. If a company’s primary listing is on a stock exchange in the same country as the company is domiciled and incorporated, then the company is assigned to that country. If the country of domicile is different from the country of incorporation and the primary listing is in the country of domicile, then the company is assigned to the country of primary listing and domicile. If the country of primary listing is different from the country of domicile and the country of primary listing is in the country of incorporation, then the company is assigned to the country of primary listing and incorporation. If the country of domicile is the same as the country of incorporation, but is different from the country of primary listing, then the company is assigned to the country of domicile and incorporation. If the country of primary listing, domicile, and incorporation all differ, and for exceptions to these rules, country assignment is based on other factors including domicile of parent company, management location, source of sales, trading volume and reporting currency. This test is used for assignment of securities and instruments of a company to the United States as well as foreign (non-U.S.) and developing (or “emerging market”) countries.

Convertible and Equity Securities

Common stock represents equity ownership in a company and typically provides the common stockholder the power to vote on certain corporate actions, including the election of the company’s directors. Common stockholders participate in company profits through dividends and, in the event of bankruptcy, distributions, on a pro-rata basis after other claims are satisfied. Many factors affect the value of common stock, including earnings, earnings forecasts, corporate events and factors impacting the issuer’s industry and the market generally. Common stock generally has the greatest appreciation and depreciation potential of all corporate securities.

The Funds may invest in convertible securities and equity securities, as well as securities related to equities. Equity-related securities include securities having an equity component (e.g., hybrids, bank capital) and equity derivatives. Convertible securities are generally preferred securities and other securities that are convertible into or exercisable for common stock at a stated price or rate. The price of a convertible security will normally vary in some proportion to changes in the price of the underlying common stock because of this conversion or exercise feature. However, the value of a convertible security may not increase or decrease as rapidly as the underlying common stock. A convertible security will normally also provide income and is subject to interest rate risk. Convertible securities may be lower-rated securities subject to greater levels of credit risk. A Fund may be forced to convert a security before it would otherwise choose, which may have an adverse effect on the Fund’s ability to achieve its investment objective.

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Prospectus

“Synthetic” convertible securities are selected based on the similarity of their economic characteristics to those of a traditional convertible security due to the combination of separate securities that possess the two principal characteristics of a traditional convertible security, i.e., an income-producing security (“income-producing component”) and the right to acquire an equity security (“convertible component”). The income-producing component is achieved by investing in non-convertible, income-producing securities such as bonds, preferred securities and money market instruments, which may be represented by derivative instruments. The convertible component is achieved by investing in securities or instruments such as warrants or options to buy common stock at a certain exercise price, or options on a stock index. A simple example of a synthetic convertible security is the combination of a traditional corporate bond with a warrant to purchase equity securities of the issuer of the bond. A Fund may also purchase synthetic securities created by other parties, typically investment banks, including convertible structured notes. The income-producing and convertible components of a synthetic convertible security may be issued separately by different issuers and at different times.

Preferred and other senior securities generally entitle the holder to receive, in preference to the holders of other securities such as common stocks, dividends and a fixed share of the proceeds resulting from a liquidation of the company. Preferred and other senior securities may pay fixed or adjustable rates of return. Preferred and other senior securities are subject to issuer-specific and market risks applicable generally to equity securities. In addition, a company’s preferred and other senior securities generally pay dividends only after the company makes required payments to holders of its bonds and other debt. For this reason, the value of preferred and other senior securities will usually react more strongly than bonds and other debt to actual or perceived changes in the company’s financial condition or prospects.

In addition, preferred and other senior securities often have special redemption rights allowing issuers to redeem such securities at par earlier than scheduled. If these rights are exercised, a Fund may have to reinvest proceeds in less attractive securities.

Among other risks described in this prospectus, the following issues are particularly associated with investments in preferred and other senior securities.

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Deferral and Omission of Distributions. Preferred and other senior securities may include features permitting or requiring the issuer to defer or omit distributions. Among other things, such deferral or omission may result in adverse tax consequences for a Fund.

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Limited Voting Rights. Preferred and other senior securities generally do not have voting rights with respect to the issuer unless dividends have been in arrears for certain specified periods of time.

In the future, preferred or other senior securities may be offered with features different from those described above, and as such, may entail different risks. Over longer periods of time, certain types of preferred or other senior securities may become more scarce or less liquid as a result

of legislative changes. Such events may result in losses to a Fund as the prices of securities it holds may be negatively affected. Revisions to bank capital requirements by international regulatory bodies, to the extent they are adopted in the United States, may also negatively impact the market for certain preferred or senior securities.

At times, in connection with the restructuring of a preferred security either outside of bankruptcy court or in the context of bankruptcy court proceedings, a Fund may determine or be required to accept equity securities, such as common stocks, in exchange for all or a portion of a preferred security. Depending upon, among other things, the Sub-Adviser’s evaluation, of the potential value of such securities in relation to the price that could be obtained by a Fund at any given time upon sale thereof, a Fund may determine to hold such securities in its portfolio.

Equity securities generally have greater price volatility than fixed income securities. The market price of equity securities owned by a Fund may go up or down, sometimes rapidly or unpredictably. Equity securities may decline in value due to factors affecting equity securities markets generally or particular industries represented in those markets. The value of an equity security may also decline for a number of reasons that directly relate to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods or services.

Small-Cap and Mid-Cap Companies

The Funds may invest in equity securities of small-capitalization and mid-capitalization companies. The Funds consider a small-cap company to be a company with a market capitalization of up to $1.5 billion and a mid-cap company to be a company with a market capitalization of between $1.5 billion and $10 billion. Investments in small-cap and mid-cap companies involve greater risk than investments in large-capitalization companies. Small and mid-cap companies may not have an established financial history, which can present valuation challenges. The equity securities of small- and mid-cap companies may be subject to increased market fluctuations, due to less liquid markets and more limited managerial and financial resources. A Fund’s investments in small- and mid-cap companies may increase the volatility of the Fund’s portfolio.

Small Companies

The PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF, PIMCO RAFI Dynamic Multi-Factor International Equity ETF and PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF may invest in small companies. Such Funds rank company size by fundamental size, as determined by the Index Provider, rather than by market capitalization. Investments in small companies involve greater risks than investments in large companies. Small companies may not have an established financial history, which can present valuation challenges. The equity securities of small companies may be subject to increased market fluctuations, due to less liquid markets and more limited managerial and financial resources, among other factors. A Fund’s investments in small companies may increase the volatility of the Fund’s portfolio.

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Focused Investment

To the extent that a Fund focuses its investments in a particular sector, the Fund may be susceptible to loss due to adverse developments affecting that sector. These developments include, but are not limited to, governmental regulation; inflation; rising interest rates; cost increases in raw materials, fuel and other operating expenses; technological innovations that may render existing products and equipment obsolete; competition from new entrants; high research and development costs; increased costs associated with compliance with environmental or other governmental regulations; and other economic, business or political developments specific to that sector. Furthermore, a Fund may invest a substantial portion of its assets in companies in related sectors that may share common characteristics, are often subject to similar business risks and regulatory burdens, and whose securities may react similarly to the types of developments described above, which will subject the Fund to greater risk. A Fund also will be subject to focused investment risk to the extent that it invests a substantial portion of its assets in a particular issuer, market, asset class, country or geographic region.

Real Estate Risk

Investments in real estate investment trusts (“REITs”) or real estate-linked derivative instruments are subject to risks similar to those associated with direct ownership of real estate, including losses from casualty or condemnation, and changes in local and general economic conditions, supply and demand, interest rates, zoning laws, regulatory limitations on rents, property taxes and operating expenses. An investment in a REIT or a real estate-linked derivative instrument that is linked to the value of a REIT is subject to additional risks, such as poor performance by the manager of the REIT, adverse changes to the tax laws or failure by the REIT to qualify for tax-free pass-through of income under the Internal Revenue Code of 1986, as amended (the “Code”). In addition, some REITs have limited diversification because they invest in a limited number of properties, a narrow geographic area, or a single type of property. Also, the organizational documents of a REIT may contain provisions that make changes in control of the REIT difficult and time-consuming. Finally, private REITs are not traded on a national securities exchange. As such, these products are generally illiquid. This reduces the ability of a Fund to redeem its investment early. Private REITs are also generally harder to value and may bear higher fees than public REITs.

Foreign (Non-U.S.) Securities

Certain Funds may invest in securities and instruments that are economically tied to foreign (non-U.S.) countries. The PIMCO RAFI Dynamic Multi-Factor International Equity ETF may invest in securities and instruments that are economically tied to the following foreign (non-U.S.) countries (which may be amended from time to time pursuant to the Index Provider’s Methodology & Standard Treatment (“rulebook”) for the Underlying Indexes): Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Hong Kong, Ireland, Israel, Italy, Japan, Netherlands, New Zealand, Norway, Portugal, Singapore, Spain, Sweden, Switzerland and United Kingdom. Securities and instruments of a company are assigned to a country based on the

company’s country of primary listing, domicile, and incorporation. If a company’s primary listing is on a stock exchange in the same country as the company is domiciled and incorporated, then the company is assigned to that country. If the country of domicile is different from the country of incorporation and the primary listing is in the country of domicile, then the company is assigned to the country of primary listing and domicile. If the country of primary listing is different from the country of domicile and the country of primary listing is in the country of incorporation, then the company is assigned to the country of primary listing and incorporation. If the country of primary listing, domicile, and incorporation all differ, and for exceptions to these rules, country assignment is based on other factors including domicile of parent company, management location, source of sales, trading volume and reporting currency. A Fund’s investments in foreign (non-U.S.) securities may include American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”), Global Depositary Receipts (“GDRs”) and similar securities that represent interests in a non-U.S. company’s securities that have been deposited with a bank or trust and that trade on a U.S. exchange or OTC. ADRs, EDRs and GDRs may be less liquid or may trade at a different price than the underlying securities of the issuer.

Investing in foreign (non-U.S.) securities involves special risks and considerations not typically associated with investing in U.S. securities. Investors should consider carefully the substantial risks involved for Funds that invest in securities issued by foreign companies and governments of foreign countries. These risks include: differences in accounting, auditing and financial reporting standards; generally higher commission rates on foreign portfolio transactions; the possibility of nationalization, expropriation or confiscatory taxation; adverse changes in investment or exchange control regulations; market disruptions; the possibility of security suspensions; and political instability. Individual foreign (non-U.S.) economies may differ favorably or unfavorably from the U.S. economy in such respects as growth of gross domestic product, rates of inflation, capital reinvestment, resources, self- sufficiency and balance of payments position. Other countries’ financial infrastructure or settlement systems may be less developed than those of the United States. The securities markets, values of securities, yields and risks associated with foreign (non-U.S.) securities markets may change independently of each other. Also, foreign (non-U.S.) securities and dividends and interest payable on those securities may be subject to foreign taxes, including taxes withheld from payments on those securities. Foreign (non-U.S.) securities often trade with less frequency and volume than domestic securities and therefore may exhibit greater price volatility. Investments in foreign (non-U.S.) securities may also involve higher custodial costs than domestic investments and additional transaction costs with respect to foreign currency conversions. Changes in, or uncertainty concerning, foreign exchange rates also will affect the value of securities denominated or quoted in foreign currencies and in some cases could lead to uncertainty regarding the reliability of issuers’ financial reporting.

The Funds that may invest in foreign (non-U.S.) securities also may invest in sovereign debt issued by governments, their agencies or instrumentalities, or other government-related entities. Holders of sovereign debt may be requested to participate in the rescheduling of

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Prospectus

such debt and to extend further loans to governmental entities. In addition, there is no bankruptcy proceeding by which defaulted sovereign debt may be collected.

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Emerging Market Securities. The PIMCO RAFI Dynamic Multi- Factor Emerging Markets Equity ETF may invest in securities and instruments that are economically tied to the following developing (or “emerging market”) countries (which may be amended from time to time pursuant to the rulebook for the Underlying Indexes): Brazil, Chile, China, Colombia, Czech Republic, Egypt, Greece, Hungary, India, Indonesia, Malaysia, Mexico, Philippines, Peru, Poland, Qatar, Russia, Saudi Arabia, South Africa, South Korea, Taiwan, Thailand, Turkey and United Arab Emirates. Securities and instruments of a company are assigned to a country based on the company’s country of primary listing, domicile, and incorporation. If a company’s primary listing is on a stock exchange in the same country as the company is domiciled and incorporated, then the company is assigned to that country. If the country of domicile is different from the country of incorporation and the primary listing is in the country of domicile, then the company is assigned to the country of primary listing and domicile. If the country of primary listing is different from the country of domicile and the country of primary listing is in the country of incorporation, then the company is assigned to the country of primary listing and incorporation. If the country of primary listing, domicile, and incorporation all differ, and for exceptions to these rules, country assignment is based on other factors including domicile of parent company, management location, source of sales, trading volume and reporting currency. The Fund is subject to the limitation on investment in emerging market securities and instruments noted in the Fund Summaries.

Investing in emerging market securities imposes risks different from, or greater than, risks of investing in domestic securities or in foreign, developed countries. These risks include: smaller market capitalization of securities markets, which may suffer periods of relative illiquidity; significant price volatility; restrictions on foreign investment; and possible repatriation of investment income and capital. In addition, foreign investors may be required to register the proceeds of sales; future economic or political crises could lead to price controls, forced mergers, expropriation or confiscatory taxation, seizure, nationalization, or creation of government monopolies. The currencies of emerging market countries may experience significant declines against the U.S. dollar, and devaluation may occur subsequent to investments in these currencies by a Fund. Many emerging market countries have experienced substantial, and in some periods extremely high, rates of inflation for many years. Inflation and rapid fluctuations in inflation rates have had, and may continue to have, negative effects on the economies and securities markets of certain emerging market countries. Additional risks of emerging market securities may include: greater social, economic and political uncertainty and instability; more substantial governmental involvement in the economy; less governmental supervision and regulation; unavailability of currency hedging techniques; companies that are newly organized and small; differences in auditing and financial reporting standards, which may result in

unavailability of material information about issuers; and less developed legal systems. In addition, emerging securities markets may have different clearance and settlement procedures, which may be unable to keep pace with the volume of securities transactions or otherwise make it difficult to engage in such transactions. Settlement problems may cause a Fund to miss attractive investment opportunities, hold a portion of its assets in cash pending investment, or be delayed in disposing of a portfolio security. Such a delay could result in possible liability to a purchaser of the security.

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Investments in Russia. The PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF may invest in securities and instruments that are economically tied to Russia. Investments in Russia are subject to various risks such as, but not limited to, political, economic, legal, market and currency risks, as discussed in the preceding “Emerging Market Securities” sub-section and in the “Investment in Russia” sub-section in the SAI. The risks include uncertain political and economic policies, short-term market volatility, poor accounting standards, corruption and crime, an inadequate regulatory system, regional armed conflict and unpredictable taxation. Investments in Russia are particularly subject to the risk that further economic sanctions may be imposed by the United States and/or other countries. Such sanctions – which may impact companies in many sectors, including energy, financial services and defense, among others –may negatively impact a Fund’s performance and/or ability to achieve its investment objective. For example, certain investments may be prohibited and/or existing investments may become illiquid (e.g., in the event that transacting in certain existing investments is prohibited), which could cause the Fund to sell other portfolio holdings at a disadvantageous time or price in order to meet shareholder redemptions. The Russian securities market is characterized by limited volume of trading, resulting in difficulty in obtaining accurate prices and trading. The Russian securities market, as compared to U.S. markets, has significant price volatility, less liquidity, a smaller market capitalization and a smaller number of traded securities. There may be little publicly available information about issuers. Settlement, clearing and registration of securities transactions are subject to risks because of registration systems that may not be subject to effective government supervision. This may result in significant delays or problems in registering the transfer of securities. Russian securities laws may not recognize foreign nominee accounts held with a custodian bank, and therefore the custodian may be considered the ultimate owner of securities they hold for their clients. Ownership of securities issued by Russian companies may be recorded by companies themselves and by registrars instead of through a central registration system. It is possible that the ownership rights of a Fund could be lost through fraud, negligence or oversight. While applicable Russian regulations impose liability on registrars for losses resulting from their errors, it may be difficult for a Fund to enforce any rights it may have against the registrar or issuer of the securities in the event of loss of share registration. To the extent that a Fund suffers a loss

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relating to title or corporate actions relating to its portfolio securities, it may be difficult for the Fund to enforce its rights or otherwise remedy the loss. Russian securities laws may not recognize foreign nominee accounts held with a custodian bank, and therefore the custodian may be considered the ultimate owner of securities they hold for their clients. Adverse currency exchange rates are a risk and there may be a lack of available currency hedging instruments. Investments in Russia may be subject to the risk of nationalization or expropriation of assets. Oil, natural gas, metals, and timber account for a significant portion of Russia’s exports, leaving the country vulnerable to swings in world prices.

Foreign (Non-U.S.) Currencies

Direct investments in foreign (non-U.S.) currencies or in securities that trade in, or receive revenues in, foreign (non-U.S.) currencies will be subject to currency risk. Foreign (non-U.S.) currency exchange rates may fluctuate significantly over short periods of time. They generally are determined by supply and demand in the foreign exchange markets and the relative merits of investments in different countries, actual or perceived changes in interest rates and other complex factors. Currency exchange rates also can be affected unpredictably by intervention (or the failure to intervene) by U.S. or foreign (non-U.S.) governments or central banks, or by currency controls or political developments. Currencies in which the Funds' assets are denominated may be devalued against the U.S. dollar, resulting in a loss to the Funds.

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Foreign Currency Transactions. Funds that invest in securities denominated in foreign (non-U.S.) currencies may engage in foreign (non-U.S.) currency transactions on a spot (cash) basis, enter into forward foreign currency exchange contracts and invest in foreign currency futures contracts and options on foreign currencies and futures. A forward foreign currency exchange contract, which involves an obligation to purchase or sell a specific currency at a future date at a price set at the time of the contract, reduces a Fund’s exposure to changes in the value of the currency it will deliver and increases its exposure to changes in the value of the currency it will receive for the duration of the contract. Certain foreign currency transactions may also be settled in cash rather than the actual delivery of the relevant currency. The effect on the value of a Fund is similar to selling securities denominated in one currency and purchasing securities denominated in another currency. Foreign currency transactions, like currency exchange rates, can be affected unpredictably by intervention (or the failure to intervene) by U.S. or foreign governments or central banks, or by currency controls or political developments. Such events may prevent or restrict a Fund’s ability to enter into foreign currency transactions, force the Fund to exit a foreign currency transaction at a disadvantageous time or price or result in penalties for the Fund, any of which may result in a loss to the Fund. A contract to sell a foreign currency would limit any potential gain that might be realized if the value of the hedged currency increases. A Fund may enter into these contracts to hedge against foreign exchange risk, to increase exposure to a

foreign currency or to shift exposure to foreign currency fluctuations from one currency to another. Suitable hedging transactions may not be available in all circumstances and there can be no assurance that a Fund will engage in such transactions at any given time or from time to time. Also, such transactions may not be successful and may eliminate any chance for a Fund to benefit from favorable fluctuations in relevant foreign currencies. A Fund may use one currency (or a basket of currencies) to hedge against adverse changes in the value of another currency (or a basket of currencies) when exchange rates between the two currencies are positively correlated. In accordance with current federal securities laws, rules and staff positions, a Fund will segregate or “earmark” assets determined to be liquid by PIMCO (or, as permitted by applicable law, enter into certain offsetting positions) to cover its obligations under forward foreign currency exchange contracts.

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Redenomination. Continuing uncertainty as to the status of the euro and the European Monetary Union (the “EMU”) has created significant volatility in currency and financial markets generally. Any partial or complete dissolution of the EMU could have significant adverse effects on currency and financial markets and on the values of a Fund’s portfolio investments. If one or more EMU countries were to stop using the euro as its primary currency, a Fund’s investments in such countries may be redenominated into a different or newly adopted currency. As a result, the value of those investments could decline significantly and unpredictably. In addition, securities or other investments that are redenominated may be subject to currency risk, liquidity risk and risk of improper valuation to a greater extent than similar investments currently denominated in euros. To the extent a currency used for redenomination purposes is not specified in respect of certain EMU-related investments, or should the euro cease to be used entirely, the currency in which such investments are denominated may be unclear, making such investments particularly difficult to value or dispose of. A Fund may incur additional expenses to the extent it is required to seek judicial or other clarification of the denomination or value of such securities. There can be no assurance that if a Fund earns income or capital gains in a non-U.S. country or the Sub-Adviser otherwise seeks to withdraw the Fund’s investments from a given country, capital controls imposed by such country will not prevent, or cause significant expense in, doing so.

Borrowings

Each Fund may borrow money to the extent permitted under the 1940 Act. This means that, in general, a Fund may borrow money from banks for any purpose in an amount up to 1∕3 of the Fund’s total assets, less all liabilities and indebtedness not represented by senior securities. A Fund may also borrow money for temporary administrative purposes in an amount not to exceed 5% of the Fund’s total assets. In addition, a Fund may borrow from certain other PIMCO funds in inter-fund lending transactions to the extent permitted by an exemptive order from the SEC.

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Derivatives

Each Fund may, but is not required to, use derivative instruments for risk management purposes or as part of its investment strategies. Generally, derivatives are financial contracts whose value depends upon, or is derived from, the value of an underlying asset, reference rate or index, and may relate to stocks, bonds, interest rates, spreads between different interest rates, currencies or currency exchange rates, commodities, and related indexes. Examples of derivative instruments include options contracts, futures contracts, options on futures contracts and swap agreements (including, but not limited to swaps on ETFs). Each Fund may invest some or all of its assets in derivative instruments, subject to the Fund’s objective and policies. A portfolio manager may decide not to employ any of these strategies and there is no assurance that any derivatives strategy used by a Fund will succeed. A description of these and other derivative instruments that the Funds may use are described under “Investment Objectives and Policies” in the SAI.

A Fund’s use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other more traditional investments. Certain derivative transactions may have a leveraging effect on a Fund. For example, a small investment in a derivative instrument may have a significant impact on a Fund’s exposure to interest rates, currency exchange rates or other investments. As a result, a relatively small price movement in a derivative instrument may cause an immediate and substantial loss or gain. A Fund may engage in such transactions regardless of whether the Fund owns the asset, instrument or components of the index underlying the derivative instrument. A Fund may invest a significant portion of its assets in these types of instruments. If it does, the Fund’s investment exposure could far exceed the value of its portfolio securities and its investment performance could be primarily dependent upon securities it does not own. A description of various risks associated with particular derivative instruments is included in “Investment Objectives and Policies” in the SAI. The following provides a more general discussion of important risk factors relating to all derivative instruments that may be used by the Funds.

Management Risk. Derivative products are highly specialized instruments that require investment techniques and risk analyses different from those associated with stocks and bonds. The use of a derivative requires an understanding not only of the underlying instrument but also of the derivative itself, without the benefit of observing the performance of the derivative under all possible market conditions.

Credit Risk. The use of certain derivative instruments involves the risk that a loss may be sustained as a result of the failure of another party to the contract (usually referred to as a “counterparty”) to make required payments or otherwise comply with the contract’s terms.

Liquidity Risk. Liquidity risk exists when a particular derivative instrument is difficult to purchase or sell. If a derivative transaction is particularly large or if the relevant market is illiquid (as is the case with many privately negotiated derivatives), it may not be possible to initiate a transaction or liquidate a position at an advantageous time or price.

Leverage Risk. Because many derivatives have a leverage component, adverse changes in the value or level of the underlying asset, reference rate or index could result in a loss substantially greater than the amount invested in the derivative itself. Certain derivatives have the potential for unlimited loss, regardless of the size of the initial investment. When a Fund uses derivatives for leverage, investments in that Fund will tend to be more volatile, resulting in larger gains or losses in response to market changes. In accordance with current federal securities laws, rules and staff positions, to limit leverage risk, each Fund will segregate or “earmark” assets determined to be liquid by PIMCO (or, as permitted by applicable regulation, enter into certain offsetting positions) to cover its obligations under derivative instruments.

Lack of Availability. Because the markets for certain derivative instruments (including markets located in foreign countries) are relatively new and still developing, suitable derivatives transactions may not be available in all circumstances for risk management or other purposes. Upon the expiration of a particular contract, a portfolio manager may wish to retain a Fund’s position in the derivative instrument by entering into a similar contract, but may be unable to do so if the counterparty to the original contract is unwilling to enter into the new contract and no other suitable counterparty can be found. There is no assurance that a Fund will engage in derivatives transactions at any time or from time to time. A Fund’s ability to use derivatives may also be limited by certain regulatory and tax considerations.

Correlation Risk. In certain cases, the value of derivatives may not correlate perfectly, or at all, with the value of the assets, reference rates or indexes they are designed to closely track. For example, a swap agreement on an ETF would not correlate perfectly with the index upon which the ETF is based because the fund’s return is net of fees and expenses. In this regard, a Fund may seek to achieve its investment objective, in part, by investing in derivatives positions that are designed to closely track the performance (or inverse performance) of an index on a daily basis. However, the overall investment strategies of the Fund are not designed or expected to produce returns which replicate the performance (or inverse performance) of the particular index, and the degree of variation could be substantial, particularly over longer periods. There are a number of factors which may prevent a Fund, or derivatives or other strategies used by a Fund, from achieving a desired correlation (or inverse correlation) with an index. These may include, but are not limited to: (i) the impact of fund fees, expenses and transaction costs, including borrowing and brokerage costs/bid-ask spreads, which are not reflected in index returns; (ii) differences in the timing of daily calculations of the value of an index and the timing of the valuation of derivatives, securities and other assets held by a Fund and the determination of the NAV of Fund shares; (iii) disruptions or illiquidity in the markets for derivative instruments or securities in which a Fund invests; (iv) a Fund having exposure to or holding less than all of the securities in the Underlying Index and/or having exposure to or holding securities not included in the Underlying Index; (v) large or unexpected movements of assets into and out of a Fund (due to share purchases or redemptions, for example), potentially resulting in the Fund being over- or under-exposed to the index; (vi) the impact of accounting standards

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or changes thereto; (vii) changes to the applicable index that are not disseminated in advance; (viii) a possible need to conform a Fund’s portfolio holdings to comply with investment restrictions or policies or regulatory or tax law requirements; and (ix) fluctuations in currency exchange rates.

Market and Other Risks. Like most other investments, derivative instruments are subject to the risk that the market value of the instrument will change in a way detrimental to a Fund's interest. If a portfolio manager incorrectly forecasts the values of securities, currencies or interest rates or other economic factors in using derivatives for a Fund, the Fund might have been in a better position if it had not entered into the transaction at all. While some strategies involving derivative instruments can reduce the risk of loss, they can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other Fund investments. A Fund may also have to buy or sell a security at a disadvantageous time or price because the Fund is legally required to maintain offsetting positions or asset coverage in connection with certain derivatives transactions. The regulation of the derivatives markets has increased over the past several years, and additional future regulation of the derivatives markets may make derivatives more costly, may limit the availability or reduce the liquidity of derivatives, or may otherwise adversely affect the value or performance of derivatives. Any such adverse future developments could impair the effectiveness or raise the costs of a Fund's derivative transactions, or impede the employment of a Fund's derivatives strategies, or adversely affect a Fund's performance.

Other risks in using derivatives include the risk of mispricing and/or improper valuation of derivatives. Many derivatives, in particular privately negotiated derivatives, are complex and often valued subjectively. Improper valuations can result in increased cash payment requirements to counterparties or a loss of value to a Fund. In addition, a Fund's use of derivatives may cause the Fund to realize higher amounts of short-term capital gains (generally taxed at ordinary income tax rates) than if the Fund had not used such instruments.

Investment in Other Investment Companies

A Fund may invest in securities of other investment companies, such as open-end or closed-end management investment companies, including ETFs or in pooled accounts or other unregistered accounts or investment vehicles to the extent permitted by the 1940 Act and the rules and regulations thereunder and any exemptive relief therefrom. A Fund may invest in other investment companies to gain broad market or sector exposure, including during periods when it has large amounts of uninvested cash or when PIMCO believes share prices of other investment companies offer attractive values. As a shareholder of an investment company or other pooled vehicle, a Fund may indirectly bear investment advisory fees, supervisory and administrative fees, service fees and other fees which are in addition to the fees the Fund pays its service providers.

Subject to the restrictions and limitations of the 1940 Act, and the rules and regulations thereunder and any exemptive relief therefrom, each Fund may, in the future, elect to pursue its investment objective either

by investing directly in securities or by investing in one or more underlying investment vehicles or companies that have substantially similar investment objectives and policies as the Fund.

Cash and Short-Term Securities

Each Fund may invest its assets in cash, cash equivalents, highly rated short-term securities, including securities issued or guaranteed by the U.S. government, its agencies or instrumentalities, money market funds and/or short-term bond funds. Securities issued by U.S. government agencies or instrumentalities may not be guaranteed by the U.S. Treasury.

Illiquid Investments

Each Fund may invest up to 15% of its net assets (taken at the time of investment) in illiquid investments that are assets. Certain illiquid investments may require pricing at fair value as determined in good faith under the supervision of the Board of Trustees. A portfolio manager may be subject to significant delays in disposing of illiquid investments, and transactions in illiquid investments may entail registration expenses and other transaction costs that are higher than those for transactions in liquid investments. The term “illiquid investments” for this purpose means investments that a 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. Restricted securities, i.e., securities subject to legal or contractual restrictions on resale, may be illiquid. However, some restricted securities (such as certain commercial paper) may be treated as liquid (i.e., classified by the Fund in a liquidity category other than “illiquid” pursuant to the Fund's liquidity risk management procedures), although they may be relatively less liquid than registered securities traded on established secondary markets. Additional discussion of illiquid investments and related regulatory limits and requirements is available under “Investment Objectives and Policies” in the SAI.

Loans of Portfolio Securities

For the purpose of achieving income, each Fund may lend its portfolio securities to brokers, dealers, and other financial institutions provided that a number of conditions are satisfied, including that the loan is fully collateralized. Please see “Investment Objectives and Policies” in the SAI for details. When a Fund lends portfolio securities, its investment performance will continue to reflect changes in the value of the securities loaned, and the Fund will also receive a fee or interest on the collateral. Securities lending involves the risk of loss of rights in the collateral or delay in recovery of the collateral if the borrower fails to return the security loaned or becomes insolvent. A Fund may pay lending fees to a party arranging the loan, which may be an affiliate of the Fund. Cash collateral received by a Fund in securities lending transactions may be invested in short-term liquid fixed income instruments or in money market or short-term mutual funds, or similar investment vehicles, including affiliated money market or short-term mutual funds. A Fund bears the risk of such investments.

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Portfolio Turnover

The length of time a Fund has held a particular security is not generally a consideration in investment decisions. A change in the securities held by a Fund is known as “portfolio turnover.” When the portfolio manager deems it appropriate and particularly during periods of volatile market movements, a Fund may engage in frequent and active trading of portfolio securities to achieve its investment objective including, without limitation, to reflect changes in a Fund’s Underlying Index, such as reconstitutions, additions or deletions of component securities. To the extent that Creation Unit purchases from and redemptions by a Fund are effected in cash, frequent purchases and redemptions may increase the rate of portfolio turnover. Higher portfolio turnover (e.g., an annual rate greater than 100% of the average value of the Fund’s portfolio) involves correspondingly greater expenses to a Fund, including brokerage commissions or dealer markups and other transaction costs on the sale of securities and reinvestments in other securities. Such sales may also result in realization of taxable capital gains, including short-term capital gains (which are generally taxed at ordinary income tax rates). The trading costs and tax effects associated with portfolio turnover may adversely affect a Fund’s performance. Please see a Fund's “Fund Summary—Portfolio Turnover” or the “Financial Highlights” in this prospectus for the portfolio turnover rates of the Funds that were operational during the last fiscal year. In addition, large movements of cash into or out of a Fund may negatively impact the Fund’s ability to achieve its investment objective or maintain a consistent level of operating expenses.

Changes in Investment Objectives and Policies

The investment objective of each Fund is non-fundamental and may be changed by the Board of Trustees without shareholder approval. Unless otherwise stated, all other investment policies of the Funds may be changed by the Board of Trustees without shareholder approval. In addition, the Trust may determine to cease operating any Fund as an “exchange-traded” fund and cause the Fund’s shares to stop trading on a securities exchange.

Percentage Investment Limitations

Unless otherwise stated, all percentage limitations on Fund investments listed in this prospectus will apply at the time of investment. A Fund would not violate these limitations unless an excess or deficiency occurs or exists immediately after and as a result of an investment.

Other Investments and Techniques

The Funds may invest in other types of securities and use a variety of investment techniques and strategies that are not described in this prospectus. These securities and techniques may subject the Funds to additional risks. Please see the SAI for additional information about the securities and investment techniques described in this prospectus and about additional securities and techniques that may be used by the Funds.

Cyber Security

As the use of technology has become more prevalent in the course of business, the Funds have become potentially more susceptible to operational and information security risks resulting from breaches in cyber security. A breach in cyber security refers to both intentional and unintentional cyber events from outside threat actors or internal resources that may, among other things, cause a Fund to lose proprietary information, suffer data corruption and/or destruction or lose operational capacity, result in the unauthorized release or other misuse of confidential information, or otherwise disrupt normal business operations. Cyber security breaches may involve unauthorized access to a Fund’s digital information systems (e.g., through “hacking” or malicious software coding) and may come from multiple sources, including outside attacks such as denial-of-service attacks (i.e., efforts to make network services unavailable to intended users) or cyber extortion, including exfiltration of data held for ransom and/or “ransomware” attacks that renders systems inoperable until ransom is paid, or insider actions. In addition, cyber security breaches involving a Fund’s third party service providers (including but not limited to advisers, sub-advisers, administrators, transfer agents, custodians, vendors, suppliers, distributors and other third parties), trading counterparties or issuers in which a Fund invests can also subject a Fund to many of the same risks associated with direct cyber security breaches. Cyber security breaches have the potential to interfere with the processing of Authorized Participant transactions and shareholder transactions in Fund shares on an exchange. Moreover, cyber security breaches involving trading counterparties or issuers in which a Fund invests could adversely impact such counterparties or issuers and cause the Fund’s investment to lose value.

Cyber security failures or breaches may result in financial losses to a Fund and its shareholders. These failures or breaches may also result in disruptions to business operations, potentially resulting in financial losses; interference with a Fund’s ability to calculate its NAV, process shareholder transactions or otherwise transact business with shareholders; impediments to trading; violations of applicable privacy and other laws; regulatory fines; penalties; third party claims in litigation; reputational damage; reimbursement or other compensation costs; additional compliance and cyber security risk management costs and other adverse consequences. In addition, substantial costs may be incurred in order to prevent any cyber incidents in the future.

Like with operational risk in general, the Funds have established business continuity plans and risk management systems designed to reduce the risks associated with cyber security. However, there are inherent limitations in these plans and systems, including that certain risks may not have been identified, in large part because different or unknown threats may emerge in the future. As such, there is no guarantee that such efforts will succeed, especially because the Funds do not directly control the cyber security systems of issuers in which a Fund may invest, trading counterparties or third party service providers to the Funds. Such entities have experienced cyber attacks and other attempts to gain unauthorized access to systems from time to time, and there is no guarantee that efforts to prevent or mitigate the effects of

November1, 2021 | Prospectus 39

Prospectus

Underlying Indexes

©2018 RAFI Indices, LLC. The trade name RAFI™ is a registered trademark of Research Affiliates, LLC. The RAFI™ Index is calculated by RAFI Indices, LLC. and all intellectual property rights in the “The RAFI ESG US Index,” “The RAFI Dynamic Multi-Factor Emerging Markets Index,” “The RAFI Dynamic Multi-Factor Developed Ex-U.S. Index,” and “The RAFI Dynamic Multi-Factor U.S. Index” (collectively, the “Index” or the “RAFI Indexes”) are the property of RAFI Indices, LLC. The RAFI Indexes are reprinted with permission. PIMCO has entered into a license agreement with RAFI Indices, LLC to use each RAFI Index. Solactive AG is the Index calculator and benchmark administrator. The value of an Index is calculated on each day on which the U.S. market or U.K. market is open for trading (“Business Day”) based on the prices on the respective Exchanges on which the Component Securities are listed. For each update, the most recent prices of all Component Securities are used. Prices of Component Securities not listed in U.S. Dollars are converted using spot foreign exchange rates quoted by Reuters. The daily index closing value is calculated using WM/Reuters closing spot rates from 4:00 pm London time. Should there be no current price available on Reuters, the most recent price or the Trading Price (as defined below) on Reuters for the preceding Trading Day (as defined below) is used in the calculation. The Index is calculated continuously every Business Day from 9:00 am to 10:30 pm, CET, with updates every 15 seconds. In the event that data cannot be provided to Reuters or to the pricing services of Boerse Stuttgart AG, the Index cannot be distributed. Any incorrect calculation is adjusted on a retrospective basis. At the time of the calculation and publication of the Index, the prices used for the calculation may already have changed.

A committee (the “Committee”) composed of staff from Solactive AG is responsible for any amendments to the rules; provided that the starting universe for the composition of an Index and its relevant specifications are established by RAFI Indices, LLC. The future composition of any Index is determined on the last business day of February, May, August and November according to the procedures outlined in the Index rulebook. The Committee shall decide about the future composition of the Index in the event that any Extraordinary Events (as defined below) should occur and the implementation of any necessary adjustments. Notwithstanding the above, Solactive AG may consult RAFI Indices, LLC for decisions regarding the composition of an Index. Members of the Committee can recommend changes to the guideline and submit them to the Committee for approval.

All specifications and information relevant for calculating the Index are made available on the https://www.solactive.de web page and sub-pages.

With regard to a Component Security, the “Trading Price” in respect of a Trading Day is the closing price on this Trading Day determined in accordance with the Exchange regulations. If the Exchange has no closing price for a Component Security, the Index calculator shall determine the Trading Price and the time of the quote for the share in question in a manner that appears reasonable to the Index calculator.

A “Trading Day” is, in relation to the Index or a Component Security, a Trading Day on the Exchange (or a day that would have been such a day if a market disruption had not occurred), excluding days on which trading may be ceased prior to the normal Exchange closing time. The Index Calculator is ultimately responsible as to whether a certain day is a Trading Day with regard to the Index or a Component Security.

An “Extraordinary Event” is

■

A merger

■

A takeover bid

■

A delisting

■

The nationalization of a company

■

Insolvency

The Trading Price for a Component Security on the day the Extraordinary Event came into effect is the last available market price for this Component Security quoted on the Exchange on the day the event came into effect (or, if a market price is not available for the day the event came into effect, the last available market price quoted on the Exchange on a day specified as appropriate by the Index Calculator), as determined by the Index Calculator, and this price is used as the Trading Price of the particular Component Security until the end of the day on which the composition of the Index is next set.

In the event of the insolvency of an issuer of a Component Security, the Component Security shall remain in the Index until the next rebalancing day. As long as a market price for the affected Component Security is available on a Business Day, this shall be applied as the Trading Price for this Component Security on the relevant Business Day, as determined in each case by the Index Calculator. If a market price is not available on a Business Day the Trading Price for this Component Security is set to zero. The Committee may also decide to eliminate the respective Component Security at an earlier point in time prior to the next rebalancing day. The procedure in this case is identical to an elimination due to an Extraordinary Event.

A Component Security is “delisted” if the Exchange announces pursuant to the Exchange regulations that the listing of, the trading in or the issuing of public quotes on the Component Security at the Exchange has ceased immediately or will cease at a later date, for whatever reason (provided delisting is not because of a Merger or a Takeover Bid), and the Component Security is not immediately listed, traded or quoted again on an exchange, trading, or listing system, acceptable to the Index Calculator.

“Insolvency” occurs with regard to a Component Security if (A) all shares of the respective issuer must be transferred to a trustee, liquidator, insolvency administrator, or a similar public officer as result of a voluntary or compulsory liquidation, insolvency or winding-up proceedings, or comparable proceedings affecting the issuer of the Component Security, or (B) the holders of the shares of this issuer are legally enjoined from transferring the shares.

A “Takeover Bid” is a bid to acquire, an exchange offer or any other offer or act of a legal person that results in the related legal person acquiring as part of an exchange or otherwise more than 10% and less than 100% of the voting shares in circulation from the issuer of the

November1, 2021 | Prospectus 41

PIMCO Equity Series

Component Security or the right to acquire these shares, as determined by the Index Calculator based on notices submitted to public or self-regulatory authorities or other information considered by the Index Calculator to be relevant.

With regard to a Component Security, a “Merger” is: 1. a change in the security class or a conversion of this share class that results in a transfer or an ultimate definite obligation to transfer all the shares in circulation to another legal person; 2. a merger (either by acquisition or through forming a new structure) or a binding obligation on the part of the issuer to exchange shares with another legal person (except in a merger or share exchange under which the issuer of this Component Security is the acquiring or remaining company and which does not involve a change in security class or a conversion of all the shares in circulation); 3. a takeover offer, exchange offer, other offer or another act of a legal person for the purposes of acquiring or otherwise obtaining from the issuer 100% of the shares issued that entails a transfer or the irrevocable obligation to transfer all shares (with the exception of shares which are held and controlled by the legal person); or 4. a merger (either by acquisition or through forming a new structure) or a binding obligation on the part of the issuer of the share or its subsidiaries to exchange shares with another legal person, whereby the issuer of the share is the acquiring or remaining company and it does not involve a change in the class or a conversion of the all shares issued, but the shares in circulation directly prior to such an event (except for shares held and controlled by the legal person) represent in total less than 50% of the shares in circulation directly subsequent to such an event.

The “Merger Date” is the date on which a Merger is concluded or the date specified by the Index Calculator if such a date cannot be determined under the law applicable to the Merger. “Nationalization” is a process whereby all shares or the majority of the assets of the issuer of the shares are nationalized or are expropriated or otherwise must be transferred to public bodies, authorities, or institutions. For purposes of this section only, “Exchange” is, in respect of the Index and every Component Security, the respective primary exchange where the Component Security has its primary listing. The Committee may decide to declare a different stock exchange the “Exchange” for trading reasons, even if the company is only listed there via a Stock Substitute. “Stock Substitute” includes, in particular, American Depositary Receipts (ADRs) and Global Depositary Receipts (GDRs).

Disclaimers

The Funds are not sponsored, promoted, offered, sold or supported in any other manner by RAFI Indices, LLC or any of its affiliates, licensors or contractors (the “RAFI Parties”) nor do any of the RAFI Parties offer any express or implicit guarantee, warranty or assurance either with regard to the results of using the RAFI Indexes or the Index prices at any time or in any other respect. The RAFI Indexes are calculated and published by the RAFI Parties. The RAFI Parties use commercially reasonable efforts to ensure that each RAFI Index is calculated correctly. None of the RAFI Parties shall be liable for any error, omission, inaccuracy, incompleteness, delay, or interruption in the RAFI Indexes or any data related thereto or have any obligation to point out errors in the RAFI Indexes to any person. Neither publication of the RAFI Indexes by the

RAFI Parties nor the licensing of the RAFI Indexes or RAFI Index trademark for the purpose of use in connection with the Funds constitutes a recommendation by any of the RAFI Parties to invest in nor does it in any way represent an assurance, endorsement or opinion of any of the RAFI Parties with regard to any investment in the Funds. The trade name RAFI™ is a registered trademark of Research Affiliates, LLC in the U.S. and other countries.

Shares of the Funds are not sponsored, endorsed or promoted by NYSE Arca. NYSE Arca makes no representation or warranty, express or implied, to the owners of shares of the Funds or any member of the public regarding the ability of the Funds to track the investment results of an Underlying Index or the ability of an Underlying Index to track fixed income performance. NYSE Arca is not responsible for, nor has it participated in, the determination of the compilation or the calculation of an Underlying Index, nor in the determination of the timing of, prices of or quantities of shares of the Funds to be issued, nor in the determination or calculation of the equation by which the shares are redeemable. NYSE Arca has no obligation or liability to owners of shares of the Funds in connection with the administration, marketing or trading of shares of the Funds. NYSE Arca does not guarantee the accuracy and/or the completeness of an Underlying Index or any data included therein. NYSE Arca makes no warranty, express or implied, as to results to be obtained by the Trust, on behalf of the Funds as licensee, licensee’s customers and counterparties, owners of shares of the Funds or any other person or entity, from the use of an Underlying Index or any data included therein in connection with the rights licensed as described herein or for any other use.

NYSE Arca makes no express or implied warranties and hereby expressly disclaims all warranties of merchantability or fitness for a particular purpose with respect to an Underlying Index or any data included therein. Without limiting any of the foregoing, in no event shall NYSE Arca have any liability for any direct, indirect, special, punitive, consequential or any other damages (including lost profits) even if notified of the possibility of such damages.

42 Prospectus | PIMCO Equity Series

PIMCO Equity Series

Financial Highlights

The financial highlights table is intended to help a shareholder understand the financial performance of each Fund for the last five fiscal years or, if shorter, the period since a Fund commenced operations. Certain information reflects financial results for a single Fund share. The total returns in the table represent the rate that an investor would have earned or lost on an investment in shares of a Fund (assuming reinvestment of all dividends and distributions). This information has been audited by PricewaterhouseCoopers LLP, whose report, along with each Fund’s financial statements, are included in the Trust’s annual report to shareholders. The annual report is available free of charge by calling the Trust at the phone number on the back of this prospectus. The annual report is also available for download free of charge on the Trust’s website at pimcoetfs.com. Note: All footnotes to the financial highlights tables appear at the end of the tables.

		Investment Operations			Less Distributions(c)

Selected Per Share Data for the Year or Period Ended^:	Net Asset Value Beginning of Year or Period(a)	Net Investment Income (Loss)(b)	Net Realized/ Unrealized Gain (Loss)	Total	From Net Investment Income	From Net Realized Capital Gains	Total
PIMCO RAFI Dynamic Multi-Factor Emerging Markets Equity ETF
06/30/2021	$20.84	$0.50	$10.14	$10.64	$(0.42)	$0.00	$(0.42)
06/30/2020	24.24	0.59	(3.41)	(2.82)	(0.58)	0.00	(0.58)
06/30/2019	23.94	0.64	0.39	1.03	(0.73)	0.00	(0.73)
08/31/2017 - 06/30/2018	25.00	0.42	(1.41)	(0.99)	(0.07)	0.00	(0.07)
PIMCO RAFI Dynamic Multi-Factor International Equity ETF
06/30/2021	$22.86	$0.69	$6.53	$7.22	$(0.42)	$0.00	$(0.42)
06/30/2020	24.94	0.53	(1.84)	(1.31)	(0.77)	0.00	(0.77)
06/30/2019	25.87	0.72	(0.89)	(0.17)	(0.76)	0.00	(0.76)
08/31/2017 - 06/30/2018	25.00	0.62	0.44	1.06	(0.19)	0.00	(0.19)
PIMCO RAFI Dynamic Multi-Factor U.S. Equity ETF
06/30/2021	$27.74	$0.52	$11.28	$11.80	$(0.54)	$0.00	$(0.54)
06/30/2020	29.21	0.62	(1.44)	(0.82)	(0.65)	0.00	(0.65)
06/30/2019	28.30	0.59	0.91	1.50	(0.59)	0.00	(0.59)
08/31/2017 - 06/30/2018	25.00	0.43	3.17	3.60	(0.30)	0.00	(0.30)
PIMCO RAFI ESG U.S. ETF
06/30/2021	$21.40	$0.51	$9.32	$9.83	$(0.51)	$0.00	$(0.51)
12/18/2019 - 06/30/2020	25.00	0.33	(3.72)	(3.39)	(0.21)	0.00	(0.21)

A zero balance may reflect actual amounts rounding to less than $0.01 or 0.01%.

Annualized, except for organization expense, if any.

(a)

Includes adjustments required by U.S. GAAP and may differ from net asset values and performance reported elsewhere by the Funds.

(b)

Per share amounts based on average number of shares outstanding during the year or period.

(c)

The tax characterization of distributions is determined in accordance with Federal income tax regulations. See Note 2, Distributions to Shareholders, in the Notes to Financial Statements for more information.

44 Prospectus | PIMCO Equity Series

		Ratios/Supplemental Data
			Ratios to Average Net Assets
Net Asset Value End of Year or Period(a)	Total Return(a)	Net Assets End of Year or Period (000s)	Expenses	Expenses Excluding Waivers	Expenses Excluding Interest Expense	Expenses Excluding Interest Expense and Waivers	Net Investment Income (Loss)	Portfolio Turnover Rate

$ 31.06	51.62%	$ 494,452	0.50 %	0.51 %	0.50 %	0.51 %	1.91 %	58 %
20.84	(11.86)	619,324	0.49	0.50	0.49	0.50	2.66	59
24.24	4.53	477,943	0.49	0.50	0.49	0.50	2.75	43
23.94	(3.99)	357,169	0.50 *	0.55 *	0.50 *	0.55 *	1.94 *	52

$29.66	31.87%	$88,978	0.40 %	0.40 %	0.40 %	0.40 %	2.54 %	48 %
22.86	(5.37)	24,231	0.40	0.41	0.40	0.41	2.21	35
24.94	(0.59)	42,888	0.39	0.40	0.39	0.40	2.96	24
25.87	4.22	28,976	0.40 *	0.87 *	0.40 *	0.87 *	2.81 *	36

$39.00	43.02%	$82,677	0.29 %	0.30 %	0.29 %	0.30 %	1.53 %	63 %
27.74	(2.80)	25,525	0.30	0.31	0.30	0.31	2.12	36
29.21	5.50	96,980	0.29	0.30	0.29	0.30	2.08	40
28.30	14.43	65,658	0.29 *	0.60 *	0.29 *	0.60 *	1.89 *	56

$30.72	46.63%	$20,584	0.30 %	0.31 %	0.30 %	0.31 %	1.91 %	32 %
21.40	(13.42)	8,988	0.30 *	0.86 *	0.30 *	0.86 *	2.75 *	12