# EDGAR Filing Document

**Accession Number:** 0001469192
**File Stem:** 0001741773-23-000558
**Filing Date:** 2023-2
**Character Count:** 51569
**Document Hash:** 809e573bcba0830fe122078bd9ebab2b
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001741773-23-000558.hdr.sgml**: 20230228

**ACCESSION NUMBER**: 0001741773-23-000558

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20230228

**DATE AS OF CHANGE**: 20230228

**EFFECTIVENESS DATE**: 20230228

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MAINSTAY FUNDS TRUST
- **CENTRAL INDEX KEY:** 0001469192
- **IRS NUMBER:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1031

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-160918
- **FILM NUMBER:** 23678729

**BUSINESS ADDRESS:**
- **STREET 1:** 51 MADISON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10010
- **BUSINESS PHONE:** 212 576 7000

**MAIL ADDRESS:**
- **STREET 1:** 51 MADISON AVENUE
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10010

## Series and Classes Contracts Data

### MainStay Equity Allocation Fund (Series ID: S000028535)

| Class ID   | Class Name     | Ticker Symbol   |
|:---|:---|:---|
| C000087365 | Investor Class | MGXNX           |
| C000087366 | Class A        | MGXAX           |
| C000087367 | Class B        | MGXBX           |
| C000087368 | Class C        | MGXCX           |
| C000087369 | Class I        | MGXIX           |
| C000166843 | Class R3       | MGXRX           |
| C000221664 | SIMPLE Class   | MGXSX           |

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| | | |
|:---|:---|:---|
| &nbsp;&nbsp;![](img_3fac685652374f1.jpg)<br>**MainStay Equity Allocation Fund** | &nbsp;&nbsp;![](img_3fac685652374f1.jpg)<br>**MainStay Equity Allocation Fund** | **Summary Prospectus**<br>February 28, 2023  |
| &nbsp;&nbsp;**Class**/Ticker | **A** MGXAX **Investor** MGXNX **B** MGXBX **C** MGXCX **I** MGXIX **R3** MGXRX **SIMPLE** MGXSX | **A** MGXAX **Investor** MGXNX **B** MGXBX **C** MGXCX **I** MGXIX **R3** MGXRX **SIMPLE** MGXSX |

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Before you invest, you may want to review the Fund's Prospectus, which contains more information about the Fund and its risks. You can find the Fund's Prospectus, reports to shareholders and other information about the Fund by going online to newyorklifeinvestments.com, by calling 800-624-6782 or by sending an e-mail to MainStayShareholderServices@nylim.com. The Fund's Prospectus and Statement of Additional Information, both dated February 28, 2023, as may be amended from time to time, are incorporated by reference into this Summary Prospectus.

**Investment Objective**

The Fund seeks long-term growth of capital.

**Fees and Expenses of the Fund** 

The table below 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.** You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in the Fund. In addition, different financial intermediary firms and financial professionals may impose different sales loads and waivers. More information about these and other discounts or waivers is available from your financial professional, in the "Information on Sales Charges" section starting on page 68 of the Prospectus and Appendix A – Intermediary-Specific Sales Charge Waivers and Discounts, and in the "Alternative Sales Arrangements" section on page 138 of the Statement of Additional Information.

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| | | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **Class A** | **Investor Class** | **Class B<sup>1</sup>** | **Class C** | **Class I** | **Class I** | **Class R3**  | **Class R3**  | **SIMPLE Class** | **SIMPLE Class** |
| **Shareholder Fees** (fees paid directly from your investment) |  |  |  |  |  |  |  |  |  |  |
| Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) | 3.00 | 2.50 |  |  |  |  |  |  |  |  |
| Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of the original offering price or redemption proceeds) | None<br><sup>2</sup>  | None<br><sup>2</sup>  | 5.00 | 1.00 |  |  |  |  |  |  |
| **Annual Fund Operating Expenses** (expenses that you pay each year as a percentage of the value of your investment) |  |  |  |  |  |  |  |  |  |  |
| Management Fees (as an annual percentage of the Fund's average daily net assets) |  |  |  |  |  |  |  |  |  |  |
| Distribution and/or Service (12b-1) Fees | 0.25 | 0.25 | 1.00 | 1.00 |  |  | 0.50 | % | 0.50 | % |
| Other Expenses | 0.12 | 0.38 | 0.38 | 0.38 | 0.12 | % | 0.22 | % | 0.26 | %<sup>3</sup> |
| Acquired (Underlying) Fund Fees and Expenses | 0.55 | 0.55 | 0.55 | 0.55 | 0.55 | % | 0.55 | % | 0.55 | % |
| Total Annual Fund Operating Expenses | 0.92 | 1.18 | 1.93 | 1.93 | 0.67 | % | 1.27 | % | 1.31 | % |
| Waivers / Reimbursements<sup>4</sup> | 0.00 | (0.08 | (0.08 | (0.08 | 0.00 | % | 0.00 | % | 0.00 | % |
| Total Annual Fund Operating Expenses After Waivers / Reimbursements<sup>4</sup> | 0.92 | 1.10 | 1.85 | 1.85 | 0.67 | % | 1.27 | % | 1.31 | % |

---

1. Class B shares are closed to all new purchases as well as additional investments by existing Class B shareholders.

2. No initial sales charge applies on investments of $250,000 or more (and certain other qualified purchases). However, a contingent deferred sales charge of 1.00% may be imposed on certain redemptions made within 18 months of the date of purchase on shares that were purchased without an initial sales charge.

3. Restated to reflect the expenses expected to be incurred during the current fiscal year.

4. New York Life Investment Management LLC ("New York Life Investments") has contractually agreed to waive fees and/or reimburse expenses so that Total Annual Fund Operating Expenses (excluding taxes, interest, litigation, extraordinary expenses, brokerage and other transaction expenses relating to the purchase or sale of portfolio investments, and acquired (underlying) fund fees and expenses) for a class do not exceed the following amounts of its average daily net assets: Class A, 0.50%; Investor Class, 0.55%; Class B, 1.30%; Class C, 1.30%; Class I, 0.25%; Class R3, 0.85%; and SIMPLE Class, 0.80%.. This agreement will remain in effect until February 28, 2024, and shall renew automatically for one-year terms unless New York Life Investments provides written notice of termination prior to the start of the next term or upon approval of the Board of Trustees of the Fund.

**Example**

The Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated whether or not you redeem all of your shares at the end of those periods (except as indicated with respect to Class B and Class C shares). The Example reflects Class B and Class C shares converting into Investor Class shares in years 9-10; expenses could be lower if you are eligible to convert to Class A shares instead. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The Example reflects the contractual fee waiver and/or expense reimbursement arrangement, if applicable, for the current duration of the arrangement only. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

<br> (NYLIM) NL252 MSAEA01 -02/23

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| | | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| **&nbsp;&nbsp;&nbsp;&nbsp;Expenses After** | **Class A** | **Investor** | **Class B** | **Class B** | **Class C** | **Class C** | **Class I** | **Class R3** | **SIMPLE** |
|  |  | **Class** | Assuming no redemption | Assuming redemption at end of period | Assuming no redemption | Assuming redemption at end of period |  |  | **Class** |
| &nbsp;&nbsp;&nbsp;&nbsp;1 Year | $&nbsp;&nbsp;&nbsp;&nbsp; 391 | $&nbsp;&nbsp;&nbsp;&nbsp; 359 | $&nbsp;&nbsp;&nbsp;&nbsp; 188 | $&nbsp;&nbsp;&nbsp;&nbsp; 688 | $&nbsp;&nbsp;&nbsp;&nbsp; 188 | $&nbsp;&nbsp;&nbsp;&nbsp; 288 | $&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;68 | $&nbsp;&nbsp;&nbsp;&nbsp; 129 | $&nbsp;&nbsp;&nbsp;&nbsp; 133 |
| &nbsp;&nbsp;&nbsp;&nbsp;3 Years | $&nbsp;&nbsp;&nbsp;&nbsp; 584 | $&nbsp;&nbsp;&nbsp;&nbsp; 608 | $&nbsp;&nbsp;&nbsp;&nbsp; 598 | $&nbsp;&nbsp;&nbsp;&nbsp; 898 | $&nbsp;&nbsp;&nbsp;&nbsp; 598 | $&nbsp;&nbsp;&nbsp;&nbsp; 598 | $&nbsp;&nbsp;&nbsp;&nbsp; 214 | $&nbsp;&nbsp;&nbsp;&nbsp; 403 | $&nbsp;&nbsp;&nbsp;&nbsp; 415 |
| &nbsp;&nbsp;&nbsp;&nbsp;5 Years | $&nbsp;&nbsp;&nbsp;&nbsp; 794 | $&nbsp;&nbsp;&nbsp;&nbsp; 875 | $1034 | $1234 | $1034 | $1034 | $&nbsp;&nbsp;&nbsp;&nbsp; 373 | $&nbsp;&nbsp;&nbsp;&nbsp; 697 | $&nbsp;&nbsp;&nbsp;&nbsp; 718 |
| &nbsp;&nbsp;&nbsp;&nbsp;10 Years | $1397 | $1639 | $2052 | $2052 | $2052 | $2052 | $&nbsp;&nbsp;&nbsp;&nbsp; 835 | $1534 | $1579 |

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**Portfolio Turnover**

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 17% of the average value of its portfolio.

**Principal Investment Strategies**

The Fund is a "fund of funds" that seeks to achieve its investment objective by investing in mutual funds and exchange-traded funds managed by New York Life Investment Management LLC ("New York Life Investments") or its affiliates (the "Underlying Funds"). The Underlying Funds are described and offered for direct investment in separate prospectuses. The Fund is designed for investors with a particular risk profile as represented by the asset class allocations described below, and invests in a distinct mix of Underlying Funds.

The Fund seeks to achieve its investment objective by normally investing substantially all of its assets in Underlying Equity Funds (normally within a range of 90% to 100%). The Fund may invest approximately 25% (within a range of 15% to 35%) of its assets in Underlying International Equity Funds. The Fund may invest up to 10% of its assets in Underlying Fixed-Income Funds. New York Life Investments may change the asset class allocations, the Underlying Funds in which the Fund invests, or the target weighting without approval from shareholders. With respect to investments in Underlying Funds that invest significantly in both U.S. and non-U.S. equity securities, New York Life Investments will generally allocate such investments equally between Underlying U.S. Equity Funds and International Equity Funds.

The Fund invests, under normal circumstances, at least 80% of its assets (net assets plus any borrowings for investment purposes) in Underlying Equity Funds. New York Life Investments will determine each Underlying Fund's asset class, and for Underlying Funds that may potentially fall into multiple asset classes, New York Life Investments will classify them based on certain factors, including, but not limited to, the Underlying Fund's investment strategy and portfolio characteristics. The Underlying Funds may engage in strategies involving non-traditional asset classes (e.g., master limited partnerships), non-traditional investment strategies (e.g., non-correlated returns or short sales) or illiquid assets.

New York Life Investments uses a two-step asset allocation process to create the Fund's portfolio. The first step includes a strategic review of the target allocations to the equity and fixed-income asset classes and a determination of any tactical allocation adjustments to establish the portion of the Fund's investable portfolio (meaning the Fund's assets available for investment, other than working cash balances) to be invested in each asset class.

The following table illustrates the Fund's target allocations among asset classes (the target allocations and/or actual holdings will vary from time to time as a result of the tactical allocation process, although these variations will remain within the ranges described above):

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| | | | | |
|:---|:---|:---|:---|:---|
|  | **U.S. Equity** | **International Equity**  | **Total Equity**  | **Fixed-Income** |
| MainStay Equity Allocation Fund | 75% | 25% | 100% | 0% |

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The second step in the portfolio's construction process involves the actual selection of Underlying Funds to represent the asset classes indicated above and determination of target weightings among the Underlying Funds. The Fund may invest in any or all of the Underlying Funds within an asset class, but will not normally invest in every Underlying Fund at one time. Selection of individual Underlying Funds is based on several factors, including, but not limited to, past performance and total portfolio characteristics (e.g., size, style, credit quality and duration). For cash management purposes, the Fund may hold a portion of its assets in U.S. government securities, cash or cash equivalents. The Fund also may invest in Underlying Funds that are money market funds.

New York Life Investments monitors the Fund's portfolio daily to ensure that the Fund's actual asset class allocations among the Underlying Funds continue to conform to the Fund's target allocations over time and may periodically adjust target asset class allocations based on various quantitative and qualitative data relating to the U.S. and international economies, securities markets, and various segments within those markets. In response to adverse market or other conditions, the Fund may, regardless of its normal asset class allocations, temporarily hold all or a portion of its assets in U.S. government securities, money market funds, cash, or cash equivalents. In connection with the asset allocation process, the Fund may from time to time invest more than 25% of its assets in one Underlying Fund.

The Fund may invest in derivatives, such as total return swaps, to seek to enhance returns or reduce the risk of loss by hedging certain of its holdings.

**Principal Risks of the Fund**

You can lose money by investing in the Fund. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. The investments selected by New York Life Investments may underperform the market in which the Fund invests or other investments. The Fund may receive large purchase or redemption orders, which may have adverse effects on performance if the Fund were required to sell securities, invest cash or hold a relatively large amount of cash at times when it would not otherwise do so.

The principal risks of investing in the Fund are summarized below.

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**Asset Allocation Risk:** Although allocation among different asset classes generally limits the Fund's exposure to the risks of any one class, the risk remains that New York Life Investments may favor an asset class that performs poorly relative to the other asset classes. For example, deteriorating economic conditions might cause an overall weakness in corporate earnings that reduces the absolute level of stock prices in that market. Under these circumstances, if the Fund, through its holdings of Underlying Funds, were invested primarily in stocks, it would perform poorly relative to a portfolio invested primarily in bonds. The Underlying Funds selected by New York Life Investments may underperform the market or other investments. Similarly, the portfolio managers of the Underlying Funds could be incorrect in their analysis of economic trends, countries, industries, companies, the relative attractiveness of asset classes or other investments. Moreover, because the Fund has set limitations on the amount of assets that normally may be allocated to each asset class, the Fund has less flexibility in its investment strategy than mutual funds that are not subject to such limitations. In addition, the asset allocations made by the Fund may not be ideal for all investors and may not effectively increase returns or decrease risk for investors.

**Conflicts of Interest:** Potential conflicts of interest situations could arise. For example, New York Life Investments may be subject to potential conflicts of interest in selecting or allocating assets among the Underlying Funds because the fees paid to it and its affiliates by some Underlying Funds are higher than the fees paid by other Underlying Funds. In addition, the Fund's portfolio managers may also serve as portfolio managers to one or more Underlying Funds and may have an incentive to select certain Underlying Funds due to compensation considerations or to support new investment strategies or cash flow needs of Underlying Funds. Moreover, a situation could occur where the best interests of the Fund could be adverse to the best interests of Underlying Funds or vice versa. New York Life Investments will analyze any such situation and take all steps it believes to be necessary to minimize and, where possible, eliminate potential conflicts.

**Exchange-Traded Fund ("ETF") Risk:** The risks of owning an ETF generally reflect the risks of owning the underlying securities that the ETF is designed to track, although lack of liquidity in an ETF's shares could result in the market price of the ETF's shares being more volatile than the value of the underlying portfolio of securities. In addition, ETFs are subject to the following risks that do not apply to conventional funds: (i) the market price of an ETF's shares may trade at a premium or a discount to their NAV; (ii) an ETF may fail to accurately track the market segment or index that underlies its investment objective and, therefore, may not produce the intended results; (iii) an active trading market for an ETF's shares may not develop or be maintained; (iv) trading in an ETF's shares on an exchange may be halted due to market conditions or other reasons; and (v) an ETF may fail to meet the requirements of the exchange necessary to maintain the listing of the ETF. Although ETFs will generally trade close to NAV, market volatility, lack of an active trading market for ETF shares, disruptions at market participants (such as authorized participants or market makers), or determinations by market participants to cease serving as authorized participants or market makers (including during times of markets stress), and any other disruptions in the ordinary functioning of the creation and redemption process may result in a lack of liquidity of ETF shares or their trading significantly at a premium or a discount to NAV. If an ETF's shares are traded outside a collateralized settlement system, the number of financial institutions that can act as authorized participants that can post collateral on an agency basis is limited, which may result in a lack of liquidity of ETF shares or their trading significantly at a premium or discount to NAV. Disruptions in the markets for the securities underlying ETFs purchased or sold by the Fund could result in losses on the Fund's investment in ETFs. If the market for an ETF's shares is open during times when the markets for some or all of the ETF's underlying investments are closed, there may be changes to the value of such investments from the last quotes of the closed market, which could lead to differences between the market value of the ETF's shares and NAV. As with conventional funds, ETFs also incur management fees, trading costs, marketing expenses and licensing fees that increase their costs versus the costs of owning the underlying securities directly.

**Focused Portfolio Risk:** To the extent that the Fund invests a significant portion of its assets in a single Underlying Fund, it will be particularly sensitive to the risks associated with that Underlying Fund and changes in the value of that Underlying Fund may have a significant effect on the net asset value of the Fund. Similarly, the extent to which an Underlying Fund invests a significant portion of its assets in a single industry or economic sector will impact the Fund's sensitivity to adverse developments affecting such industry or sector.

**Large Transaction Risks: To minimize disruptions to the operations of the Fund and the Underlying Funds, New York Life Investments seeks to maintain existing target allocations and to implement small changes to target allocations through the netting of purchases and redemptions of Fund shares. These practices may temporarily affect New York Life Investments' ability to fully implement the Fund's investment strategies.**

**Portfolio Management Risk:** The investment strategies, practices and risk analyses used by New York Life Investments may not produce the desired results or expected returns.

**Derivatives Risk:** Derivatives are investments whose value depends on (or is derived from) the value of an underlying instrument, such as a security, asset, reference rate or index. Derivative strategies may be riskier than investing directly in the underlying instrument and often involve leverage, which may exaggerate a loss, potentially causing the Fund to lose more money than it originally invested and would have lost had it invested directly in the underlying instrument. Derivatives may be difficult to sell, unwind and/or value. Derivatives may also be subject to counterparty risk, which is the risk that the counterparty (the party on the other side of the transaction) on a derivative transaction will be unable or unwilling to honor its contractual obligations to the Fund. Swaps may be subject to counterparty credit, correlation, valuation, liquidity and leveraging risks. Swap transactions tend to shift a Fund's investment exposure from one type of investment to another and may entail the risk that a party will default on its payment obligations to the Fund. Additionally, applicable regulators have adopted rules imposing certain margin requirements, including minimums on uncleared swaps, which may result in the Fund and its counterparties posting higher margin amounts for uncleared swaps. Certain standardized swaps are subject to mandatory central clearing and exchange trading. Central clearing, which interposes a central clearinghouse to each participant's swap, and exchange trading are intended to reduce counterparty credit risk and increase liquidity but neither makes swap transactions risk-free. Derivatives may also increase the expenses of the Fund.

**Principal Risks of the Underlying Funds**

The principal risks of the Underlying Funds in which the Fund invests, which could adversely affect the performance of the Fund, may include the risks summarized below. For purposes of the risks summarized below, the terms "Fund" and "Funds" may also refer to "Underlying Fund" or "Underlying Funds" as the context requires.

**Market Risk:** Changes in markets may cause the value of investments to fluctuate, which could cause the Fund to underperform other funds with similar investment objectives and strategies. Such changes may be rapid and unpredictable. From time to time, markets may experience periods of stress as a result

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of various market and economic factors for potentially prolonged periods that may result in: (i) increased market volatility; (ii) reduced market liquidity; and (iii) increased redemptions of shares. Such conditions may add significantly to the risk of volatility in the net asset value of the Fund's shares and adversely affect the Fund and its investments.

**Portfolio Management Risk:** The investment strategies, practices and risk analyses used by a Fund's manager or subadvisor may not produce the desired results or expected returns. A Fund's manager or subadvisor may give consideration to certain ESG criteria when evaluating an investment opportunity. The application of ESG criteria may result in a Fund (i) having exposure to certain securities or industry sectors that are significantly different than the composition of the Fund's benchmark; and (ii) performing differently than other funds and strategies in its peer group that do not take into account ESG criteria or the Fund's benchmark.

**Derivatives Risk:** Derivatives are investments whose value depends on (or is derived from) the value of an underlying instrument, such as a security, asset, reference rate or index. Derivative strategies may be riskier than investing directly in the underlying instrument and often involve leverage, which may exaggerate a loss, potentially causing a Fund to lose more money than it originally invested and would have lost had it invested directly in the underlying instrument. For example, if a Fund is the seller of credit protection in a credit default swap, the Fund effectively adds leverage to its portfolio and is subject to the credit exposure on the full notional value of the swap. Derivatives may be difficult to sell, unwind and/or value. Derivatives may also be subject to counterparty risk, which is the risk that the counterparty (the party on the other side of the transaction) on a derivative transaction will be unable or unwilling to honor its contractual obligations to a Fund. Futures may be more volatile than direct investments in the instrument underlying the contract, and may not correlate perfectly to the underlying instrument. Futures and other derivatives also may involve a small initial investment relative to the risk assumed, which could result in losses greater than if they had not been used. Due to fluctuations in the price of the underlying instrument, a Fund may not be able to profitably exercise an option and may lose its entire investment in an option. To the extent that the Fund writes or sells an option, if the decline in the value of the underlying instrument is significantly below the exercise price in the case of a written put option or increase above the exercise price in the case of a written call option, the Fund could experience a substantial loss. Forward commitments entail the risk that the instrument may be worth less when it is issued or received than the price a Fund agreed to pay when it made the commitment. The use of foreign currency forwards may result in currency exchange losses due to fluctuations in currency exchange rates or an imperfect correlation between portfolio holdings denominated in a particular currency and the forward contracts entered into by a Fund.

Swaps may be subject to counterparty credit, correlation, valuation, liquidity and leveraging risks. Swap transactions tend to shift a Fund's investment exposure from one type of investment to another and may entail the risk that a party will default on its payment obligations to the Fund. Additionally, applicable regulators have adopted rules imposing certain margin requirements, including minimums on uncleared swaps, which may result in a Fund and its counterparties posting higher margin amounts for uncleared swaps. Certain standardized swaps are subject to mandatory central clearing and exchange trading. Central clearing, which interposes a central clearinghouse to each participant's swap, and exchange trading are intended to reduce counterparty credit risk and increase liquidity but neither makes swap transactions risk-free. Derivatives may also increase the expenses of a Fund.

**Equity Securities Risk:** Investments in common stocks and other equity securities are particularly subject to the risk of changing economic, stock market, industry and company conditions and the risks inherent in the ability to anticipate such changes that can adversely affect the value of portfolio holdings.

**Debt Securities Risk:** The risks of investing in debt or fixed-income securities include (without limitation): (i) credit risk, e.g., the issuer or guarantor of a debt security may be unable or unwilling (or be perceived as unable or unwilling) to make timely principal and/or interest payments or otherwise honor its obligations, or changes in an issuer's credit rating or the market's perception of an issuer's creditworthiness may affect the value of the Fund's investments; (ii) maturity risk, e.g., a debt security with a longer maturity may fluctuate in value more than one with a shorter maturity; (iii) market risk, e.g., low demand for debt securities may negatively impact their price; (iv) interest rate risk, e.g., when interest rates go up, the value of a debt security generally goes down, and when interest rates go down, the value of a debt security generally goes up (long-term debt securities are generally more susceptible to interest rate risk than short-term debt securities); and (v) call or prepayment risk, e.g., during a period of falling interest rates, the issuer may redeem a security by repaying it early, which may reduce a Fund's income if the proceeds are reinvested at lower interest rates.

Interest rate risk is the risk that the value of a Fund's investments in fixed income or debt securities will change because of changes in interest rates. There is a risk that interest rates across the financial system may change, possibly significantly and/or rapidly. Changes in interest rates or a lack of market participants may lead to decreased liquidity and increased volatility in the fixed-income or debt markets, making it more difficult for a Fund to sell its fixed-income or debt holdings. Decreased liquidity in the fixed-income or debt markets also may make it more difficult to value some or all of a Fund's fixed-income or debt holdings. For most fixed-income investments, when market interest rates fall, prices of fixed-rate debt securities rise. However, when market interest rates fall, prices of certain variable and fixed-rate debt securities may be adversely affected (i.e., falling interest rates bring the possibility of prepayment risk, as an instrument may be redeemed before maturity). Very low or negative interest rates may magnify interest rate risk. Low interest rates (or negative interest rates) may magnify the risks associated with rising interest rates. The Fund may also be subject to heightened interest rate risk when the Federal Reserve raises interest rates. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, may result in heightened market volatility and may detract from Fund performance to the extent a Fund is exposed to such interest rates and/or volatility. Other factors that may affect the value of debt securities include, but are not limited to, economic, political, public health, and other crises and responses by governments and companies to such crises.

Not all U.S. government debt securities are guaranteed by the U.S. government—some are backed only by the issuing agency, which must rely on its own resources to repay the debt. The Fund's yield will fluctuate with changes in short-term interest rates.

**Foreign Securities Risk:** Investments in foreign (non-U.S.) securities may be riskier than investments in U.S. securities. Foreign regulatory regimes and securities markets can have less stringent investor protections and disclosure standards and less liquid trading markets than U.S. regulatory regimes and securities markets, and can experience political, social and economic developments that may affect the value of investments in foreign securities. Foreign securities may also subject the Fund's investments to changes in currency rates. Changes in the value of foreign currencies may make the return on an investment increase or decrease, unrelated to the quality or performance of the investment itself. Economic sanctions may be, and have been, imposed against certain countries, organizations, companies, entities and/or individuals. Economic sanctions and other similar governmental actions or developments

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could, among other things, effectively restrict or eliminate the Fund's ability to purchase or sell certain foreign securities or groups of foreign securities, and thus may make the Fund's investments in such securities less liquid or more difficult to value. Such sanctions may also cause a decline in the value of securities issued by the sanctioned country or companies located in or economically tied to the sanctioned country. In addition, as a result of economic sanctions and other similar governmental actions or developments, the Fund may be forced to sell or otherwise dispose of foreign investments at inopportune times or prices. The Fund may seek to hedge against its exposure to changes in the value of foreign currency, but there is no guarantee that such hedging techniques will be successful in reducing any related foreign currency valuation risk.

**Growth Stock Risk:** If growth companies do not increase their earnings at a rate expected by investors, the market price of the stock may decline significantly, even if earnings show an absolute increase. Growth company stocks also typically lack the dividend yield that can cushion stock prices in market downturns.

**High-Yield Securities Risk:** Investments in high-yield securities or non-investment grade securities (commonly referred to as "junk bonds") are considered speculative because investments in such securities present a greater risk of loss than investments in higher quality securities. Such securities may, under certain circumstances, be less liquid than higher rated securities. These securities pay investors a premium (a high interest rate or yield) because of the potential illiquidity and increased risk of loss. These securities can also be subject to greater price volatility. In times of unusual or adverse market, economic or political conditions, these securities may experience higher than normal default rates.

**Liquidity and Valuation Risk:** A Fund's investments may be illiquid at the time of purchase or liquid at the time of purchase and subsequently become illiquid due to, among other things, events relating to the issuer of the securities, market events, operational issues, economic conditions, investor perceptions or lack of market participants. The lack of an active trading market may make it difficult to sell or obtain an accurate price for a security. If market conditions or issuer specific developments make it difficult to value securities, a Fund may value these securities using more subjective methods, such as fair value pricing. In such cases, the value determined for a security could be different than the value realized upon such security's sale. As a result, an investor could pay more than the market value when buying shares or receive less than the market value when selling shares. This could affect the proceeds of any redemption or the number of shares an investor receives upon purchase. The Fund is subject to the risk that it could not meet redemption requests within the allowable time period without significant dilution of remaining investors' interests in the Fund. To meet redemption requests or to raise cash to pursue other investment opportunities, the Fund may be forced to sell securities at an unfavorable time and/or under unfavorable conditions, which may adversely affect the Fund's performance.

**Market Capitalization Risk:** Investments in securities issued by small-, mid-, or large-cap companies will be subject to the risks associated with securities issued by companies of the applicable market capitalization. Securities of small-cap and mid-cap companies may be subject to greater price volatility, significantly lower trading volumes, cyclical, static or moderate growth prospects and greater spreads between their bid and ask prices than securities of larger companies. Smaller capitalization companies frequently rely on narrower product lines and niche markets and may be more vulnerable to adverse business or market developments. Securities issued by larger companies may have less growth potential and may not be able to attain the high growth rates of successful smaller companies, especially during strong economic periods. In addition, larger companies may be less capable of responding quickly to competitive challenges and industry changes, including those resulting from improvements in technology, and may suffer sharper price declines as a result of earnings disappointments. There is a risk that the securities issued by companies of a certain market capitalization may underperform the broader market at any given time.

**Mortgage-Related and Other Asset-Backed Securities Risk:** Investments in mortgage-related securities (such as mortgage-backed securities) and other asset-backed securities generally involve a stream of payments based on the underlying obligations. These payments, which are often part interest and part return of principal, vary based on the rate at which the underlying borrowers repay their loans or other obligations. Asset-backed securities are subject to the risk that borrowers may default on the underlying obligations and that, during periods of falling interest rates, these obligations may be called or prepaid and, during periods of rising interest rates, obligations may be paid more slowly than expected. Impairment of the underlying obligations or collateral, such as by non-payment, will reduce the security's value. Enforcing rights against such collateral in events of default may be difficult or insufficient. The value of these securities may be significantly affected by changes in interest rates, the market's perception of issuers, and the creditworthiness of the parties involved. The ability of a Fund to successfully utilize these instruments may depend on the ability of the Fund's manager or subadvisor to forecast interest rates and other economic factors correctly. These securities may have a structure that makes their reaction to interest rate changes and other factors difficult to predict, making their value highly volatile.

**Real Estate Investment Trust ("REIT") Risk:** Investments in REITs involve risks associated with direct ownership of real estate, including decline in property values, extended vacancies, increases in property taxes and changes in interest rates. Additionally, the appreciation of securities issued by a REIT depends, in part, on the skills of the REIT's manager. REITs may not be diversified, may experience substantial cost in the event of borrower or lessee defaults and are subject to heavy cash flow dependency.

**Short Sales Risk:** If a security sold short increases in price, a Fund may have to cover its short position at a higher price than the short sale price, resulting in a loss, which could be theoretically unlimited. A Fund may have substantial short positions and must borrow those securities to make delivery to the buyer. A Fund may not be able to borrow a security that it needs to deliver or it may not be able to close out a short position at an acceptable price and may have to sell related long positions before it had intended to do so. Thus, a Fund may not be able to successfully implement its short sale strategy due to limited availability of desired securities or for other reasons. By investing the proceeds received from selling securities short, a Fund is employing a form of leverage which creates special risks.

A Fund may also be required to pay a premium and other transaction costs, which would increase the cost of the security sold short. The amount of any gain will be decreased, and the amount of any loss increased, by the amount of the premium, dividends, interest or expenses a Fund may be required to pay in connection with the short sale.

Until a Fund replaces a borrowed security, it is required to maintain a segregated account of cash or liquid assets with a broker or custodian to cover a Fund's short position. Generally, securities held in a segregated account cannot be sold unless they are replaced with other liquid assets. A Fund's ability to access the pledged collateral may also be impaired in the event the broker fails to comply with the terms of the contract. In such instances, a Fund may not

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be able to substitute or sell the pledged collateral. Additionally, a Fund must maintain sufficient liquid assets (less any additional collateral pledged to or held by the broker), marked-to-market daily, to cover the short sale obligation. This may limit a Fund's investment flexibility, as well as its ability to meet redemption requests or other current obligations.

Because losses on short sales arise from increases in the value of the security sold short, such losses are theoretically unlimited. By contrast, a loss on a long position arises from decreases in the value of the security and is limited by the fact that a security's value cannot go below zero.

**Regulatory Risk:** A Fund as well as the issuers of the securities and other instruments in which the Fund invests are subject to considerable regulation and the risks associated with adverse changes in laws and regulations governing their operations. For example, regulatory authorities in the United States or other countries may prohibit or restrict the ability of a Fund to fully implement its short-selling strategy, either generally or with respect to certain industries or countries, which may impact the Fund's ability to fully implement its investment strategies.

**Value Stock Risk:** Value stocks may never reach what a Fund's portfolio manager believes is their full value or they may go down in value. In addition, different types of stocks tend to shift in and out of favor depending on market and economic conditions, and therefore the performance of Funds that invest in value stocks may be lower or higher than that of funds that invest in other types of equity securities.

**Master Limited Partnerships ("MLPs") and Other Natural Resources Sector Companies Risks:** Natural resources sector companies, including energy companies and MLPs, are subject to risks, including, but not limited to, fluctuations in the prices of commodities, a significant decrease in the production of or a sustained decline in demand for commodities, and construction risk, development risk, acquisition risk or other risks arising from their specific business strategies. Energy companies are affected by worldwide energy prices and may suffer losses as a result of adverse changes in these prices and market volatility. Additionally, energy companies may be at risk for increased government regulation and intervention and litigation. In addition, investing in MLPs involves certain risks related to investing in the underlying assets of the MLPs and risks associated with pooled investment vehicles. MLPs are subject to certain risks inherent in the structure of MLPs, including (i) tax risks; (ii) the limited ability to elect or remove management or the general partner or managing member; (iii) limited voting rights; and (iv) conflicts of interest between the general partner or managing member and its affiliates, on the one hand, and the limited partners or members, on the other hand, including those arising from incentive distribution payments or corporate opportunities. Securities issued by MLPs may experience limited trading volumes and, thus, may be relatively illiquid.

**Past Performance**

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual returns compare with those of two broad-based securities market indices as well as a composite index over time. Sales loads, if any, are not reflected in the bar chart. If they were, returns would be less than those shown. The Fund has selected the Standard & Poor's 500<sup><sup>®</sup></sup> Index ("S&P 500<sup><sup>®</sup></sup>Index") as its primary benchmark. The Fund has selected the MSCI EAFE<sup><sup>®</sup></sup> Index (Net) as its secondary benchmark. The Fund has selected the Equity Allocation Composite Index as an additional benchmark, which is comprised of the Fund's primary and secondary benchmark indices as described below.

Index returns reflect no deductions for fees, expenses or taxes, except for foreign withholding taxes where applicable.

Performance data for the classes varies based on differences in their fee and expense structures. Performance data is not shown for classes with less than one calendar year of performance. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Please visit newyorklifeinvestments.com/funds for more recent performance information.

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#### Annual Returns, Class I Shares

#### (by calendar year 2013-2022)
![PerformanceBarChartData(2013:32.64, 2014:5.33, 2015:-3.17, 2016:7.74, 2017:21.53, 2018:-13.55, 2019:24.63, 2020:15.69, 2021:20.79, 2022:-17.24)](img_38b51094a0e34f1.jpg)

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| | |
|:---|:---|
| **Best Quarter** | **Best Quarter** |
| 2020, Q2 | 20.50% |
| **Worst Quarter** | **Worst Quarter** |
| 2020, Q1 | -22.40% |

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**Average Annual Total Returns** (for the periods ended December 31, 2022)

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| | | | | |
|:---|:---|:---|:---|:---|
| | <br>Inception<br>| <br>&nbsp;&nbsp;&nbsp;&nbsp; 1 Year<br> | <br>5 Years<br> | 10 Years or<br>Since<br>Inception |
| Return Before Taxes |  |  |  |  |
| &nbsp;&nbsp;&nbsp;Class I | 4/4/2005 | -17.24% | 4.50% | 8.24% |
| Return After Taxes on Distributions |  |  |  |  |
| &nbsp;&nbsp;&nbsp;Class I |  | -19.32% | 2.20% | 6.48% |
| Return After Taxes on Distributions and Sale of Fund Shares |  |  |  |  |
| &nbsp;&nbsp;&nbsp;Class I |  | -8.94% | 3.22% | 6.42% |
| Return Before Taxes |  |  |  |  |
| &nbsp;&nbsp;&nbsp;Class A | 4/4/2005 | -19.96% | 3.04% | 7.35% |
| &nbsp;&nbsp;&nbsp;Investor Class | 2/28/2008 | -19.68% | 2.88% | 7.18% |
| &nbsp;&nbsp;&nbsp;Class B | 4/4/2005 | -21.97% | 3.00% | 6.99% |
| &nbsp;&nbsp;&nbsp;Class C | 4/4/2005 | -18.97% | 3.29% | 7.00% |
| &nbsp;&nbsp;&nbsp;Class R3 | 2/29/2016 | -17.80% | 3.85% | 8.07% |
| &nbsp;&nbsp;&nbsp;SIMPLE Class | 8/31/2020 | -17.77% | N/A | 4.00% |
| S&P 500<sup>®</sup> Index<sup>1</sup> | S&P 500<sup>®</sup> Index<sup>1</sup> | -18.11% | 9.42% | 12.56% |
| MSCI EAFE<sup>®</sup> Index (Net)<sup>2</sup> | MSCI EAFE<sup>®</sup> Index (Net)<sup>2</sup> | -14.45% | 1.54% | 4.67% |
| Equity Allocation Composite Index<sup>3</sup> | Equity Allocation Composite Index<sup>3</sup> | -17.13% | 7.47% | 10.64% |

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1. The S&P 500<sup><sup>®</sup></sup> Index is widely regarded as the standard index for measuring large-cap U.S. stock market performance.

2. The MSCI EAFE<sup><sup>®</sup></sup> Index (Net) consists of international stocks representing the developed world outside of North America.

3. The Equity Allocation Composite Index consists of the S&P 500<sup><sup>®</sup></sup> Index and the MSCI EAFE<sup><sup>®</sup></sup> Index weighted 75% and 25%, respectively.

After-tax returns are calculated using the highest individual federal marginal income tax rates in effect at the time of each distribution or capital gain or upon the sale of Fund shares, and do not reflect the impact of state and local taxes. 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 shares at the end of the measurement period. Actual after-tax returns depend on your tax situation and may differ from those shown. After-tax returns are not relevant if you hold your shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns shown are for Class I shares. After-tax returns for the other share classes may vary.

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**Management**

New York Life Investment Management LLC serves as the Manager. The individuals listed below are jointly and primarily responsible for day-to-day portfolio management.

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| | | |
|:---|:---|:---|
| **Manager** | **Portfolio Managers** | **Service Date** |

---

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| | | |
|:---|:---|:---|
| New York Life Investment Management LLC | Jae S. Yoon, Senior Managing Director | Since 2011 |
|  | Jonathan Swaney, Managing Director | Since 2005 |
|  | Poul Kristensen, Managing Director | Since 2013 |
|  | Amit Soni, Director | Since 2016 |

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**How to Purchase and Sell Shares**

You may purchase or sell shares of the Fund on any day the Fund is open for business by contacting your financial adviser or financial intermediary firm, or by contacting the Fund by telephone at **800-624-6782**, by mail at MainStay Funds, P.O. Box 219003, Kansas City, MO 64121-9000, by overnight mail to 430 West 7<sup>th</sup> Street, Suite 219003, Kansas City, MO 64105-1407, or by accessing our website at newyorklifeinvestments.com/accounts. SIMPLE Class shares are generally only available to SIMPLE IRA Plan accounts. SIMPLE Class shares are generally not available to retail accounts. Generally, an initial investment minimum of $1,000 applies if you invest in Investor Class or Class C shares, $15,000 for Class A shares and $1,000,000 for individual investors in Class I shares investing directly (i) with the Fund; or (ii) through certain private banks and trust companies that have an agreement with NYLIFE Distributors LLC, the Fund's principal underwriter and distributor, or its affiliates. A subsequent investment minimum of $50 applies to investments in Investor Class and Class C shares. However, for Investor Class and Class C shares purchased through AutoInvest, MainStay's systematic investment plan, a $500 initial investment minimum and a $50 minimum for subsequent purchases applies. Class A shares have no subsequent investment minimum. Class R3 shares, SIMPLE Class shares and institutional shareholders in Class I shares have no initial or subsequent investment minimums. Class B shares are closed to all new purchases and additional investments by existing Class B shareholders.

Certain financial intermediaries through whom you may invest may impose their own investment minimums, fees, policies and procedures for purchasing and selling Fund shares, which are not described in this Prospectus or the Statement of Additional Information, and which will depend on the policies, procedures and trading platforms of the financial intermediary. Consult a representative of your financial intermediary about the availability of shares of the Fund and the intermediary's policies, procedures and other information.

**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.

**Compensation to Financial Intermediary Firms**

If you purchase Fund shares through a financial intermediary firm (such as a broker/dealer or bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the financial intermediary firm or your financial adviser to recommend the Fund over another investment. Ask your financial adviser or visit your financial intermediary firm's website for more information.

"New York Life Investments" is both a service mark, and the common trade name, of certain investment advisors affiliated with New York Life Insurance Company.

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