Management Techniques Risk. The investment strategies, techniques, and risk analyses employed by the subadvisers, while designed to enhance potential returns, may not produce the desired results or expected returns, which may cause the Fund to not meet its investments objective, or underperform its benchmark index or funds with similar investment objectives and strategies. The subadvisers may be incorrect in their assessments of the values of securities or their assessments of market trends, which can result in losses to the Fund.

Quantitative Model Risk. One or more subadvisers to the Fund follows a quantitative model strategy to manage its allocated portion of the Fund. Quantitative models (both proprietary models developed by a quantitative-focused subadviser, and those supplied by third parties) and information and data supplied by third parties can be incorrect, misleading or incomplete, and any decisions made in reliance thereon can expose the Fund to potential risks of loss. In addition, the use of predictive models can also expose the Fund to potential risks of loss. For example, such models may incorrectly forecast future behavior, leading to potential losses on a cash flow and/or a mark-to-market basis. In addition, in unforeseen or certain low-probability scenarios (often involving a market disruption of some kind), such models may produce unexpected results, which can result in losses for the Fund.

If the assumptions made by quantitative-focused subadvisers in their underlying models are unrealistic, inaccurate or become unrealistic or inaccurate and are not promptly adjusted to account for changes in the overall market environment, it is likely that profitable trading signals will not be generated. If and to the extent that the models do not reflect certain factors, and a quantitative-focused subadviser does not successfully address such omission through its testing and evaluation, and modify the models accordingly, the Fund may experience losses. In addition, because of the complexity of quantitative-focused investment strategy programming and modeling, there is a risk that the finished model may contain an error; one or more of such errors could adversely affect the Fund’s performance.

To the extent that a quantitative-focused subadviser is not able to develop sufficiently differentiated models, the Fund’s investment objective may not be met, irrespective of whether the models are profitable in an absolute sense, as a result of “crowding” or “convergence” of the model’s output with actions taken by other market participants. In addition, to the extent a quantitative subadviser’s model focuses on identifying a certain type of stock (e.g., high relative profitability stocks), those stocks may perform differently from the market as a whole, which could cause the Fund to underperform.

The models and proprietary research of a quantitative subadviser are largely protected by the subadviser through the use of policies, procedures, agreements, and similar measures designed to create and enforce robust confidentiality, non-disclosure, and similar safeguards. However, aggressive position-level public disclosure obligations (or disclosure obligations to exchanges or regulators with insufficient privacy safeguards) could lead to opportunities for competitors to reverse-engineer a subadviser’s models and data, and thereby impair the relative or absolute performance of the Fund.

Value Stock Risk. The value of a company’s equity securities is subject to changes in the company’s financial condition, and overall market and economic conditions. Value stocks represent companies that tend to have lower than average price to book value ratios, price to earnings ratios, or other financial ratios. These companies may have relatively weak balance sheets and, during economic downturns, these companies may have insufficient cash flow to pay their debt obligations and difficulty finding additional financing needed for their operations. A particular value stock may not increase in price, as anticipated by a subadviser, if other investors fail to recognize the stock’s value or the catalyst that the subadviser believes will increase the price of the stock does not affect the price of the stock in the manner or to the degree that the subadviser anticipates. Also, cyclical stocks tend to increase in value more quickly during economic upturns than non-cyclical stocks, but also tend to lose value more quickly in economic downturns. The stocks of companies that a subadviser believes are undervalued compared to their intrinsic value can continue to be undervalued for long periods of time, may not realize their expected value, and can be volatile.

Derivatives Risk. The Fund may engage in a variety of transactions involving derivatives, such as options, futures, forwards and swap agreements. Derivatives are financial instruments, the values of which depend upon, or are derived from, the value of something else, such as one or more underlying investments, pools of investments, indices, or currencies. A subadviser may use derivatives both for hedging and non-hedging purposes, although it is anticipated that the use of derivatives by the Fund will generally be limited to maintaining exposure to certain market segments or asset classes, increasing or decreasing currency exposure, or facilitating certain portfolio transactions. A subadviser may also use derivatives such as exchange-listed equity futures contracts, swaps and currency forwards to equitize cash held in the portfolio. Investments in derivatives may be applied toward meeting a requirement to invest in a particular kind of investment if the derivatives have economic characteristics similar to that investment.

Derivatives involve special risks and may result in losses. The successful use of derivatives depends on the ability of a subadviser to manage these sophisticated instruments. The prices of derivatives may move in unexpected ways due to the use of leverage or other factors, especially in unusual market conditions, and may result in increased volatility of the Fund’s share price. Certain derivatives

are subject to counterparty risk, which is the risk that the other party to the transaction will not fulfill its contractual obligations, and risks arising from margin requirements, which include the risk that the Fund will be required to pay additional margin or set aside additional collateral to maintain open derivative positions. Certain derivatives are subject to mandatory central clearing and exchange-trading. Central clearing is intended to reduce counterparty credit risk, but central clearing does not make derivatives transactions risk-free Exchange-trading is intended to increase liquidity, but there is no guarantee the Fund could consider exchange-traded derivatives to be liquid. Some derivatives are more sensitive to interest rate changes and market movements than other instruments. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.

Certain derivative instruments provide the economic effect of financial leverage by creating additional investment exposure, as well as the potential for greater loss. If a subadviser uses leverage through purchasing derivative instruments, the Fund has the risk of capital losses that exceed the net assets of the allocable portion of the Fund managed by that subadviser. The net asset value of the Fund employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

Leverage Risk. If the Fund makes investments in options, futures, forwards, swap agreements and other derivative instruments, these derivative instruments provide the economic effect of financial leverage by creating additional investment exposure, as well as the potential for greater loss. If a subadviser uses leverage through purchasing derivative instruments, the Fund has the risk of capital losses that exceed the net assets of the allocable portion of the Fund managed by that subadviser. The net asset value of a Fund employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

The Fund offers four different classes of shares in this prospectus: Adviser Class shares, Class I shares, Class Y-2 shares and Class Y-3 shares. No information is shown for Adviser Class, Class I or Class Y-2 shares because there were no shares outstanding for these classes as of the last calendar year end. Performance information for these share classes will appear in a future version of the prospectus once there is a full calendar year of performance information to report. The returns of these share classes would have been substantially similar to the returns of Class Y-3 shares; however, because the Adviser Class, Class I and Class Y-2 shares are subject to a 12b-1 fee and/or a non-distribution shareholder administrative services fee, the returns of these share classes would have been lower than those shown for Class Y-3 shares.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. This may be particularly true given that other subadvisers were responsible for managing portions of the Fund’s portfolio during previous periods. Effective June 27, 2016, the Fund changed certain of its subadvisers and revised its principal investment strategies. For periods prior to June 27, 2016, the Fund’s past performance in the bar chart and table reflects the Fund’s prior subadviser lineup and principal investment strategies. Brandywine Global Investment Management, LLC assumed responsibility for managing a portion of the Fund’s portfolio on October 21, 2011. Jennison Associates LLC assumed responsibility for managing a portion of the Fund’s portfolio on April 15, 2019. O’Shaughnessy Asset Management, LLC assumed responsibility for managing a portion of the Fund’s portfolio on October 20, 2010. Parametric Portfolio Associates LLC assumed responsibility for managing a portion of the Fund’s portfolio on February 25, 2015. Polen Capital Management, LLC assumed responsibility for managing a portion of the Fund’s portfolio on April 15, 2019. Delaware Investments Fund Advisers, a series of Macquarie Investment Business Trust, assumed responsibility for managing a portion of the Fund’s portfolio on July 1, 2019.

Value Stock Risk. The value of a company’s equity securities is subject to changes in the company’s financial condition, and overall market and economic conditions. Value stocks represent companies that tend to have lower than average price to book value ratios, price to earnings ratios, or other financial ratios. These companies may have relatively weak balance sheets and, during economic downturns, these companies may have insufficient cash flow to pay their debt obligations and difficulty finding additional financing needed for their operations. A particular value stock may not increase in price, as anticipated by a subadviser, if other investors fail to recognize the stock’s value or the catalyst that the subadviser believes will increase the price of the stock does not affect the price of the stock in the manner or to the degree that the subadviser anticipates. Also, cyclical stocks tend to increase in value more quickly during economic upturns than non-cyclical stocks, but also tend to lose value more quickly in economic downturns. The stocks of companies that a subadviser believes are undervalued compared to their intrinsic value can continue to be undervalued for long periods of time, may not realize their expected value, and can be volatile.

Derivatives Risk. The Fund may engage in a variety of transactions involving derivatives, such as options, futures, forwards and swap agreements. Derivatives are financial instruments, the values of which depend upon, or are derived from, the value of something else, such as one or more underlying investments, pools of investments, indices, or currencies. A subadviser may use derivatives both for hedging and non-hedging purposes, although it is anticipated that the use of derivatives by the Fund will generally be limited to maintaining exposure to certain market segments or asset classes, increasing or decreasing currency exposure, or facilitating certain portfolio transactions. A subadviser may also use derivatives such as exchange-listed equity futures contracts, swaps and currency forwards to equitize cash held in the portfolio. Investments in derivatives may be applied toward meeting a requirement to invest in a particular kind of investment if the derivatives have economic characteristics similar to that investment.

Derivatives involve special risks and may result in losses. The successful use of derivatives depends on the ability of a subadviser to manage these sophisticated instruments. The prices of derivatives may move in unexpected ways due to the use of leverage or other factors, especially in unusual market conditions, and may result in increased volatility of the Fund’s share price. Certain derivatives are subject to counterparty risk, which is the risk that the other party to the transaction will not fulfill its contractual obligations, and risks arising from margin requirements, which include the risk that the Fund will be required to pay additional margin or set aside additional collateral to maintain open derivative positions. Certain derivatives are subject to mandatory central clearing and exchange-trading. Central clearing is intended to reduce counterparty credit risk, but central clearing does not make derivatives transactions risk-free Exchange-trading is intended to increase liquidity, but there is no guarantee the Fund could consider exchange-traded derivatives to be liquid. Some derivatives are more sensitive to interest rate changes and market movements than other instruments. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.

Certain derivative instruments provide the economic effect of financial leverage by creating additional investment exposure, as well as the potential for greater loss. If a subadviser uses leverage through purchasing derivative instruments, the Fund has the risk of capital losses that exceed the net assets of the allocable portion of the Fund managed by that subadviser. The net asset value of the Fund employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

Management Techniques Risk. The investment strategies, techniques, and risk analyses employed by the subadvisers, while designed to enhance potential returns, may not produce the desired results or expected returns, which may cause the Fund to not meet its

investments objective, or underperform its benchmark index or funds with similar investment objectives and strategies. The subadvisers may be incorrect in their assessments of the values of securities or their assessments of market trends, which can result in losses to the Fund.

Quantitative Model Risk. One or more subadvisers to the Fund follows a quantitative model strategy to manage its allocated portion of the Fund. Quantitative models (both proprietary models developed by a quantitative-focused subadviser, and those supplied by third parties) and information and data supplied by third parties can be incorrect, misleading or incomplete, and any decisions made in reliance thereon can expose the Fund to potential risks of loss. In addition, the use of predictive models can also expose the Fund to potential risks of loss. For example, such models may incorrectly forecast future behavior, leading to potential losses on a cash flow and/or a mark-to-market basis. In addition, in unforeseen or certain low-probability scenarios (often involving a market disruption of some kind), such models may produce unexpected results, which can result in losses for the Fund.

If the assumptions made by quantitative-focused subadvisers in their underlying models are unrealistic, inaccurate or become unrealistic or inaccurate and are not promptly adjusted to account for changes in the overall market environment, it is likely that profitable trading signals will not be generated. If and to the extent that the models do not reflect certain factors, and a quantitative-focused subadviser does not successfully address such omission through its testing and evaluation, and modify the models accordingly, the Fund may experience losses. In addition, because of the complexity of quantitative-focused investment strategy programming and modeling, there is a risk that the finished model may contain an error; one or more of such errors could adversely affect the Fund’s performance.

To the extent that a quantitative-focused subadviser is not able to develop sufficiently differentiated models, the Fund’s investment objective may not be met, irrespective of whether the models are profitable in an absolute sense, as a result of “crowding” or “convergence” of the model’s output with actions taken by other market participants. In addition, to the extent a quantitative subadviser’s model focuses on identifying a certain type of stock (e.g., high relative profitability stocks), those stocks may perform differently from the market as a whole, which could cause the Fund to underperform.

The models and proprietary research of a quantitative subadviser are largely protected by the subadviser through the use of policies, procedures, agreements, and similar measures designed to create and enforce robust confidentiality, non-disclosure, and similar safeguards. However, aggressive position-level public disclosure obligations (or disclosure obligations to exchanges or regulators with insufficient privacy safeguards) could lead to opportunities for competitors to reverse-engineer a subadviser’s models and data, and thereby impair the relative or absolute performance of the Fund.

Leverage Risk. If the Fund makes investments in options, futures, forwards, swap agreements and other derivative instruments, these derivative instruments provide the economic effect of financial leverage by creating additional investment exposure, as well as the potential for greater loss. If a subadviser uses leverage through purchasing derivative instruments, the Fund has the risk of capital losses that exceed the net assets of the allocable portion of the Fund managed by that subadviser. The net asset value of a Fund employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

The Fund offers four different classes of shares in this prospectus: Adviser Class shares, Class I shares, Class Y-2 shares and Class Y-3 shares. No information is shown for Adviser Class, Class I or Class Y-2 shares because there were no shares outstanding for these classes as of the last calendar year end. Performance information for these share classes will appear in a future version of the prospectus once there is a full calendar year of performance information to report. The returns of these share classes would have been substantially similar to the returns of Class Y-3 shares; however, because the Adviser Class, Class I and Class Y-2 shares are subject to a 12b-1 fee and/or a non-distribution shareholder administrative services fee, the returns of these share classes would have been lower than those shown for Class Y-3 shares.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. This may be particularly true given that other subadvisers were responsible for managing portions of the Fund’s portfolio during previous periods. Effective June 27, 2016, the Fund changed certain of its subadvisers and revised its principal investment strategies. For periods prior to June 27, 2016, the Fund’s past performance in the bar chart and table reflects the Fund’s prior subadviser lineup and principal investment strategies. GW&K Investment Management, LLC assumed responsibility for managing a portion of the Fund’s portfolio on July 1, 2016. Loomis, Sayles & Company, L.P. assumed responsibility for managing a portion of the Fund’s portfolio on July 1, 2016. LSV Asset Management assumed responsibility for managing a portion of the Fund’s portfolio on July 1, 2016. Parametric Portfolio Associates LLC assumed responsibility for managing a portion of the Fund’s portfolio on February 25, 2015. River Road Asset Management, LLC assumed responsibility for managing a portion of the Fund’s portfolio on April 30, 2019. Westfield Capital Management Company, L.P. assumed responsibility for managing a portion of the Fund’s portfolio on August 15, 2005.

Certain subadvisers may employ a quantitative investment process in seeking to achieve the Fund’s investment objective, which may lead to higher than expected portfolio turnover for the Fund.

Value Stock Risk. The value of a company’s equity securities is subject to changes in the company’s financial condition, and overall market and economic conditions. Value stocks represent companies that tend to have lower than average price to book value ratios, price to earnings ratios, or other financial ratios. These companies may have relatively weak balance sheets and, during economic downturns, these companies may have insufficient cash flow to pay their debt obligations and difficulty finding additional financing needed for their operations. A particular value stock may not increase in price, as anticipated by a subadviser, if other investors fail to recognize the stock’s value or the catalyst that the subadviser believes will increase the price of the stock does not affect the price of the stock in the manner or to the degree that the subadviser anticipates. Also, cyclical stocks tend to increase in value more quickly during economic upturns than non-cyclical stocks, but also tend to lose value more quickly in economic downturns. The stocks of companies that a subadviser believes are undervalued compared to their intrinsic value can continue to be undervalued for long periods of time, may not realize their expected value, and can be volatile.

Derivatives Risk. The Fund may engage in a variety of transactions involving derivatives, such as options, futures, forwards and swap agreements. Derivatives are financial instruments, the values of which depend upon, or are derived from, the value of something else, such as one or more underlying investments, pools of investments, indices, or currencies. A subadviser may use derivatives both for hedging and non-hedging purposes, although it is anticipated that the use of derivatives by the Fund will generally be limited to maintaining exposure to certain market segments or asset classes, increasing or decreasing currency exposure, or facilitating certain portfolio transactions. A subadviser may also use derivatives such as exchange-listed equity futures contracts, swaps and currency forwards to equitize cash held in the portfolio. Investments in derivatives may be applied toward meeting a requirement to invest in a particular kind of investment if the derivatives have economic characteristics similar to that investment.

Derivatives involve special risks and may result in losses. The successful use of derivatives depends on the ability of a subadviser to manage these sophisticated instruments. The prices of derivatives may move in unexpected ways due to the use of leverage or other factors, especially in unusual market conditions, and may result in increased volatility of the Fund’s share price. Certain derivatives are subject to counterparty risk, which is the risk that the other party to the transaction will not fulfill its contractual obligations, and risks arising from margin requirements, which include the risk that the Fund will be required to pay additional margin or set aside additional collateral to maintain open derivative positions. Certain derivatives are subject to mandatory central clearing and exchange-trading. Central clearing is intended to reduce counterparty credit risk, but central clearing does not make derivatives transactions risk-free Exchange-trading is intended to increase liquidity, but there is no guarantee the Fund could consider exchange-traded derivatives to be liquid. Some derivatives are more sensitive to interest rate changes and market movements than other instruments. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.

Certain derivative instruments provide the economic effect of financial leverage by creating additional investment exposure, as well as the potential for greater loss. If a subadviser uses leverage through purchasing derivative instruments, the Fund has the risk of capital losses that exceed the net assets of the allocable portion of the Fund managed by that subadviser. The net asset value of the Fund employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

Emerging Markets Investments Risk. Emerging markets securities involve unique risks, such as exposure to economies that are less diverse and mature than those of the United States or more established foreign markets. Also, emerging markets securities are subject to the same risks as foreign investments, described above. Generally, these risks are more severe for issuers in countries with emerging capital markets. Also, economic or political instability may cause larger price changes in emerging markets securities than in other foreign investments. Additionally, companies in emerging market countries may not be subject to accounting, auditing, financial reporting and recordkeeping requirements that are as robust as those in more developed countries and therefore, material information about a company may be unavailable or unreliable, and U.S. regulators may be unable to enforce a company’s regulatory obligations.

Quantitative Model Risk. One or more subadvisers to the Fund follows a quantitative model strategy to manage its allocated portion of the Fund. Quantitative models (both proprietary models developed by a quantitative-focused subadviser, and those supplied by third parties) and information and data supplied by third parties can be incorrect, misleading or incomplete, and any decisions made in reliance thereon can expose the Fund to potential risks of loss. In addition, the use of predictive models can also expose the Fund to potential risks of loss. For example, such models may incorrectly forecast future behavior, leading to potential losses on a cash flow and/or a mark-to-market basis. In addition, in unforeseen or certain low-probability scenarios (often involving a market disruption of some kind), such models may produce unexpected results, which can result in losses for the Fund.

If the assumptions made by quantitative-focused subadvisers in their underlying models are unrealistic, inaccurate or become unrealistic or inaccurate and are not promptly adjusted to account for changes in the overall market environment, it is likely that profitable trading signals will not be generated. If and to the extent that the models do not reflect certain factors, and a quantitative-focused subadviser does not successfully address such omission through its testing and evaluation, and modify the models accordingly, the Fund may experience losses. In addition, because of the complexity of quantitative-focused investment strategy programming and modeling, there is a risk that the finished model may contain an error; one or more of such errors could adversely affect the Fund’s performance.

To the extent that a quantitative-focused subadviser is not able to develop sufficiently differentiated models, the Fund’s investment objective may not be met, irrespective of whether the models are profitable in an absolute sense, as a result of “crowding” or “convergence” of the model’s output with actions taken by other market participants. In addition, to the extent a quantitative subadviser’s model focuses on identifying a certain type of stock (e.g., high relative profitability stocks), those stocks may perform differently from the market as a whole, which could cause the Fund to underperform.

The models and proprietary research of a quantitative subadviser are largely protected by the subadviser through the use of policies, procedures, agreements, and similar measures designed to create and enforce robust confidentiality, non-disclosure, and similar safeguards. However, aggressive position-level public disclosure obligations (or disclosure obligations to exchanges or regulators with insufficient privacy safeguards) could lead to opportunities for competitors to reverse-engineer a subadviser’s models and data, and thereby impair the relative or absolute performance of the Fund.

Management Techniques Risk. The investment strategies, techniques, and risk analyses employed by the subadvisers, while designed to enhance potential returns, may not produce the desired results or expected returns, which may cause the Fund to not meet its investments objective, or underperform its benchmark index or funds with similar investment objectives and strategies. The subadvisers may be incorrect in their assessments of the values of securities or their assessments of market trends, which can result in losses to the Fund.

Leverage Risk. If the Fund makes investments in options, futures, forwards, swap agreements and other derivative instruments, these derivative instruments provide the economic effect of financial leverage by creating additional investment exposure, as well as the potential for greater loss. If a subadviser uses leverage through purchasing derivative instruments, the Fund has the risk of capital losses that exceed the net assets of the allocable portion of the Fund managed by that subadviser. The net asset value of a Fund employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

The Fund offers four different classes of shares in this prospectus: Adviser Class shares, Class I shares, Class Y-2 shares and Class Y-3 shares. No information is shown for Adviser Class or Class Y-2 shares because there were no shares outstanding for these classes as of the last calendar year end. No information is shown for Class I shares because Class I shares commenced operations on July 22, 2021 and do not have a full calendar year of performance as of the date of the prospectus. Performance information for Adviser Class shares, Class I shares and Class Y-2 will appear in a future version of the prospectus once there is a full calendar year of performance information to report. The returns of these share classes would have been substantially similar to the returns of Class Y-3 shares; however, because the Adviser Class, Class I and Class Y-2 shares are subject to a 12b-1 fee and/or a non-distribution shareholder administrative services fee, the returns of these share classes would have been lower than those shown for Class Y-3 shares.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. This may be particularly true given that other subadvisers were responsible for managing portions of the Fund’s portfolio during previous periods. American Century Investment Management, Inc. assumed responsibility for managing a portion of the Fund’s portfolio on November 15, 2013. Arrowstreet Capital, Limited Partnership assumed responsibility for managing a portion of the Fund’s portfolio on December 16, 2010. LSV Asset Management assumed responsibility for managing a portion of the Fund’s portfolio on July 2, 2015. Massachusetts Financial Services Company assumed responsibility for managing a portion of the Fund’s portfolio on November 13, 2009. Parametric Portfolio Associates LLC assumed responsibility for managing a portion of the Fund’s portfolio on February 25, 2015.

Certain subadvisers may employ a systematic and quantitative investment process in seeking to achieve the Fund’s investment objective, which may lead to higher than expected portfolio turnover for the Fund.

Emerging market countries include all countries represented by the MSCI Emerging Markets Index. In determining if a security is economically tied to an emerging market country the Fund generally looks to the country of incorporation of the issuer as listed on Bloomberg, a widely recognized provider of market information. The Fund’s subadvisers may determine a security is economically tied to an emerging market country based on other factors, such as an issuer’s country of domicile, where the majority of an issuer’s revenues are generated or where an issuer’s primary exchange is located. As a result, a security may be economically tied to more than one country. With respect to derivative instruments, the Fund generally considers such instruments to be economically tied to emerging market countries if the underlying assets of the derivatives are (i) foreign currencies (or baskets or indices of such currencies); (ii) instruments or securities that are issued by foreign governments or by an issuer economically tied to an emerging market country as described above; or (iii) for certain money market instruments, if either the issuer or the guarantor of such money market instrument is economically tied to an emerging market country as described above.

Value Stock Risk. The value of a company’s equity securities is subject to changes in the company’s financial condition, and overall market and economic conditions. Value stocks represent companies that tend to have lower than average price to book value ratios, price to earnings ratios, or other financial ratios. These companies may have relatively weak balance sheets and, during economic downturns, these companies may have insufficient cash flow to pay their debt obligations and difficulty finding additional financing needed for their operations. A particular value stock may not increase in price, as anticipated by a subadviser, if other investors fail to

recognize the stock’s value or the catalyst that the subadviser believes will increase the price of the stock does not affect the price of the stock in the manner or to the degree that the subadviser anticipates. Also, cyclical stocks tend to increase in value more quickly during economic upturns than non-cyclical stocks, but also tend to lose value more quickly in economic downturns. The stocks of companies that a subadviser believes are undervalued compared to their intrinsic value can continue to be undervalued for long periods of time, may not realize their expected value, and can be volatile.

Leverage Risk. If the Fund makes investments in options, futures, forwards, swap agreements and other derivative instruments, these derivative instruments provide the economic effect of financial leverage by creating additional investment exposure, as well as the potential for greater loss. If a subadviser uses leverage through purchasing derivative instruments, the Fund has the risk of capital losses that exceed the net assets of the allocable portion of the Fund managed by that subadviser. The net asset value of a Fund employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

Quantitative Model Risk. One or more subadvisers to the Fund follows a quantitative model strategy to manage its allocated portion of the Fund. Quantitative models (both proprietary models developed by a quantitative-focused subadviser, and those supplied by third parties) and information and data supplied by third parties can be incorrect, misleading or incomplete, and any decisions made in reliance thereon can expose the Fund to potential risks of loss. In addition, the use of predictive models can also expose the Fund to potential risks of loss. For example, such models may incorrectly forecast future behavior, leading to potential losses on a cash flow and/or a mark-to-market basis. In addition, in unforeseen or certain low-probability scenarios (often involving a market disruption of some kind), such models may produce unexpected results, which can result in losses for the Fund.

If the assumptions made by quantitative-focused subadvisers in their underlying models are unrealistic, inaccurate or become unrealistic or inaccurate and are not promptly adjusted to account for changes in the overall market environment, it is likely that profitable trading signals will not be generated. If and to the extent that the models do not reflect certain factors, and a quantitative-focused subadviser does not successfully address such omission through its testing and evaluation, and modify the models accordingly, the Fund may experience losses. In addition, because of the complexity of quantitative-focused investment strategy programming and modeling, there is a risk that the finished model may contain an error; one or more of such errors could adversely affect the Fund’s performance.

To the extent that a quantitative-focused subadviser is not able to develop sufficiently differentiated models, the Fund’s investment objective may not be met, irrespective of whether the models are profitable in an absolute sense, as a result of “crowding” or “convergence” of the model’s output with actions taken by other market participants. In addition, to the extent a quantitative subadviser’s model focuses on identifying a certain type of stock (e.g., high relative profitability stocks), those stocks may perform differently from the market as a whole, which could cause the Fund to underperform.

The models and proprietary research of a quantitative subadviser are largely protected by the subadviser through the use of policies, procedures, agreements, and similar measures designed to create and enforce robust confidentiality, non-disclosure, and similar safeguards. However, aggressive position-level public disclosure obligations (or disclosure obligations to exchanges or regulators with insufficient privacy safeguards) could lead to opportunities for competitors to reverse-engineer a subadviser’s models and data, and thereby impair the relative or absolute performance of the Fund.

Management Techniques Risk. The investment strategies, techniques, and risk analyses employed by the subadvisers, while designed to enhance potential returns, may not produce the desired results or expected returns, which may cause the Fund to not meet its investments objective, or underperform its benchmark index or funds with similar investment objectives and strategies. The subadvisers may be incorrect in their assessments of the values of securities or their assessments of market trends, which can result in losses to the Fund.

Derivatives Risk. The Fund may engage in a variety of transactions involving derivatives, such as options, futures, forwards and swap agreements. Derivatives are financial instruments, the values of which depend upon, or are derived from, the value of something else, such as one or more underlying investments, pools of investments, indices, or currencies. A subadviser may use derivatives both for hedging and non-hedging purposes, although it is anticipated that the use of derivatives by the Fund will generally be limited to maintaining exposure to certain market segments or asset classes, increasing or decreasing currency exposures, or facilitating certain portfolio transactions. A subadviser may also use derivatives such as exchange-listed equity futures contracts, swaps and currency forwards to equitize cash held in the portfolio. Investments in derivatives may be applied toward meeting a requirement to invest in a particular kind of investment if the derivatives have economic characteristics similar to that investment.

Derivatives involve special risks and may result in losses. The successful use of derivatives depends on the ability of a subadviser to manage these sophisticated instruments. The prices of derivatives may move in unexpected ways due to the use of leverage or other factors, especially in unusual market conditions, and may result in increased volatility of the Fund’s share price. Certain derivatives are subject to counterparty risk, which is the risk that the other party to the transaction will not fulfill its contractual obligations, and risks arising from margin requirements, which include the risk that the Fund will be required to pay additional margin or set aside additional collateral to maintain open derivative positions. Certain derivatives are subject to mandatory central clearing and exchange-trading. Central clearing is intended to reduce counterparty credit risk, but central clearing does not make derivatives transactions risk-free Exchange-trading is intended to increase liquidity, but there is no guarantee the Fund could consider exchange-traded derivatives to be liquid. Some derivatives are more sensitive to interest rate changes and market movements than other instruments. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.

Certain derivative instruments provide the economic effect of financial leverage by creating additional investment exposure, as well as the potential for greater loss. If a subadviser uses leverage through purchasing derivative instruments, the Fund has the risk of capital losses that exceed the net assets of the allocable portion of the Fund managed by that subadviser. The net asset value of the Fund employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

The Fund offers four different classes of shares in this prospectus: Adviser Class shares, Class I shares, Class Y-2 shares and Class Y-3 shares. No information is shown for Adviser Class, Class I or Class Y-2 shares because these there were no shares outstanding for these classes as of the last calendar year end. Performance information for these share classes will appear in a future version of the prospectus once there is a full calendar year of performance information to report. The returns of these share classes would have been substantially similar to the returns of Class Y-3 shares; however, because the Adviser Class, Class I and Class Y-2 shares are subject to a 12b-1 fee and/or a non-distribution shareholder administrative services fee, the returns of these share classes would have been lower than those shown for Class Y-3 shares.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. This may be particularly true given that other subadvisers were responsible for managing portions of the Fund’s portfolio during previous periods. Parametric Portfolio Associates LLC assumed responsibility for managing a portion of the Fund’s portfolio on February 25, 2015. William Blair Investment Management, LLC assumed responsibility for managing a portion of the Fund’s portfolio on June 21, 2016. Origin Asset Management LLP assumed responsibility for managing a portion of the Fund’s portfolio on July 1, 2019. BennBridge US LLC, Grantham, Mayo, Van Otterloo & Co. LLC and Schroder Investment Management North America Inc. and Schroder Investment Management North America Limited assumed responsibility for managing portions of the Fund’s portfolio on March 15, 2021.

These costs, which are not reflected in Annual Fund Operating Expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 59% of the average value of its portfolio.

Certain subadvisers may employ a systematic and quantitative investment process in seeking to achieve the Fund’s investment objective, which may lead to higher than expected portfolio turnover for the Fund.

Management Techniques Risk. The investment strategies, techniques, and risk analyses employed by the subadvisers, while designed to enhance potential returns, may not produce the desired results or expected returns, which may cause the Fund to not meet its investments objective, or underperform its benchmark index or funds with similar investment objectives and strategies. The subadvisers may be incorrect in their assessments of the values of securities or their assessments of market trends, which can result in losses to the Fund.

Quantitative Model Risk. One or more subadvisers to the Fund follows a quantitative model strategy to manage its allocated portion of the Fund. Quantitative models (both proprietary models developed by a quantitative-focused subadviser, and those supplied by third parties) and information and data supplied by third parties can be incorrect, misleading or incomplete, and any decisions made in reliance thereon can expose the Fund to potential risks of loss. In addition, the use of predictive models can also expose the Fund to potential risks of loss. For example, such models may incorrectly forecast future behavior, leading to potential losses on a cash flow and/or a mark-to-market basis. In addition, in unforeseen or certain low-probability scenarios (often involving a market disruption of some kind), such models may produce unexpected results, which can result in losses for the Fund.

If the assumptions made by quantitative-focused subadvisers in their underlying models are unrealistic, inaccurate or become unrealistic or inaccurate and are not promptly adjusted to account for changes in the overall market environment, it is likely that profitable trading signals will not be generated. If and to the extent that the models do not reflect certain factors, and a quantitative-focused subadviser does not successfully address such omission through its testing and evaluation, and modify the models accordingly, the Fund may experience losses. In addition, because of the complexity of quantitative-focused investment strategy programming and modeling, there is a risk that the finished model may contain an error; one or more of such errors could adversely affect the Fund’s performance.

To the extent that a quantitative-focused subadviser is not able to develop sufficiently differentiated models, the Fund’s investment objective may not be met, irrespective of whether the models are profitable in an absolute sense, as a result of “crowding” or “convergence” of the model’s output with actions taken by other market participants. In addition, to the extent a quantitative

subadviser’s model focuses on identifying a certain type of stock (e.g., high relative profitability stocks), those stocks may perform differently from the market as a whole, which could cause the Fund to underperform.

The models and proprietary research of a quantitative subadviser are largely protected by the subadviser through the use of policies, procedures, agreements, and similar measures designed to create and enforce robust confidentiality, non-disclosure, and similar safeguards. However, aggressive position-level public disclosure obligations (or disclosure obligations to exchanges or regulators with insufficient privacy safeguards) could lead to opportunities for competitors to reverse-engineer a subadviser’s models and data, and thereby impair the relative or absolute performance of the Fund.

Value Stock Risk. The value of a company’s equity securities is subject to changes in the company’s financial condition, and overall market and economic conditions. Value stocks represent companies that tend to have lower than average price to book value ratios, price to earnings ratios, or other financial ratios. These companies may have relatively weak balance sheets and, during economic downturns, these companies may have insufficient cash flow to pay their debt obligations and difficulty finding additional financing needed for their operations. A particular value stock may not increase in price, as anticipated by a subadviser, if other investors fail to recognize the stock’s value or the catalyst that the subadviser believes will increase the price of the stock does not affect the price of the stock in the manner or to the degree that the subadviser anticipates. Also, cyclical stocks tend to increase in value more quickly during economic upturns than non-cyclical stocks, but also tend to lose value more quickly in economic downturns. The stocks of companies that a subadviser believes are undervalued compared to their intrinsic value can continue to be undervalued for long periods of time, may not realize their expected value, and can be volatile.

Emerging Markets Investments Risk. Emerging markets securities involve unique risks, such as exposure to economies that are less diverse and mature than those of the United States or more established foreign markets. Also, emerging markets securities are subject to the same risks as foreign investments, described above. Generally, these risks are more severe for issuers in countries with emerging capital markets. Also, economic or political instability may cause larger price changes in emerging markets securities than in other foreign investments. Additionally, companies in emerging market countries may not be subject to accounting, auditing, financial reporting and recordkeeping requirements that are as robust as those in more developed countries and therefore, material information about a company may be unavailable or unreliable, and U.S. regulators may be unable to enforce a company’s regulatory obligations.

Derivatives Risk. The Fund may engage in a variety of transactions involving derivatives, such as options, futures, forwards and swap agreements. Derivatives are financial instruments, the values of which depend upon, or are derived from, the value of something else, such as one or more underlying investments, pools of investments, indices, or currencies. A subadviser may use derivatives both for hedging and non-hedging purposes, although it is anticipated that the use of derivatives by the Fund will generally be limited to maintaining exposure to certain market segments or asset classes, increasing or decreasing currency exposure, or facilitating certain portfolio transactions. A subadviser may also use derivatives such as exchange-listed equity futures contracts, swaps and currency

forwards to equitize cash held in the portfolio. Investments in derivatives may be applied toward meeting a requirement to invest in a particular kind of investment if the derivatives have economic characteristics similar to that investment.

Derivatives involve special risks and may result in losses. The successful use of derivatives depends on the ability of a subadviser to manage these sophisticated instruments. The prices of derivatives may move in unexpected ways due to the use of leverage or other factors, especially in unusual market conditions, and may result in increased volatility of the Fund’s share price. Certain derivatives are subject to counterparty risk, which is the risk that the other party to the transaction will not fulfill its contractual obligations, and risks arising from margin requirements, which include the risk that the Fund will be required to pay additional margin or set aside additional collateral to maintain open derivative positions. Certain derivatives are subject to mandatory central clearing and exchange-trading. Central clearing is intended to reduce counterparty credit risk, but central clearing does not make derivatives transactions risk-free Exchange-trading is intended to increase liquidity, but there is no guarantee the Fund could consider exchange-traded derivatives to be liquid. Some derivatives are more sensitive to interest rate changes and market movements than other instruments. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately.

Certain derivative instruments provide the economic effect of financial leverage by creating additional investment exposure, as well as the potential for greater loss. If a subadviser uses leverage through purchasing derivative instruments, the Fund has the risk of capital losses that exceed the net assets of the allocable portion of the Fund managed by that subadviser. The net asset value of the Fund employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

Leverage Risk. If the Fund makes investments in options, futures, forwards, swap agreements and other derivative instruments, these derivative instruments provide the economic effect of financial leverage by creating additional investment exposure, as well as the potential for greater loss. If a subadviser uses leverage through purchasing derivative instruments, the Fund has the risk of capital losses that exceed the net assets of the allocable portion of the Fund managed by that subadviser. The net asset value of a Fund employing leverage will be more volatile and sensitive to market movements. Leverage may involve the creation of a liability that requires the Fund to pay interest.

The Fund offers four different classes of shares in this prospectus: Adviser Class shares, Class I shares, Class Y-2 shares and Class Y-3 shares. No information is shown for Adviser Class, Class I or Class Y-2 shares because there were no shares outstanding for these classes as of the last calendar year end. Performance information for these share classes will appear in a future version of the prospectus once there is a full calendar year of performance information to report. The returns of these share classes would have been substantially similar to the returns of Class Y-3 shares; however, because the Adviser Class, Class I and Class Y-2 shares are subject to a 12b-1 fee and/or a non-distribution shareholder administrative services fee, the returns of these share classes would have been lower than those shown for Class Y-3 shares.

The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. This may be particularly true given that other subadvisers were responsible for managing portions of the Fund’s portfolio during previous periods. Acadian Asset Management LLC assumed responsibility for managing a portion of the Fund’s portfolio on October 12, 2012. Martingale Asset Management, L.P. assumed responsibility for managing a portion of the Fund’s portfolio on February 23, 2015. Parametric Portfolio Associates LLC assumed responsibility for managing a portion of the Fund’s portfolio on February 25, 2015. Veritas Asset Management LLP assumed responsibility for managing a portion of the Fund’s portfolio on December 10, 2018. Ninety One North America, Inc. assumed responsibility for managing a portion of the Fund’s portfolio on April 30, 2021.