Sep. 29, 2026

GMO Opportunistic Income Fund | GMO Opportunistic Income Fund

Investment objective

Capital appreciation and current income.

Fees and expenses

The table below describes the fees and expenses that you may bear for each class of shares 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.

Annual Fund operating expenses (expenses that you bear each year as a percentage of the value of your investment)

	ETF Class
Management fee		0.55%1
Distribution and/or Service (12b-1) fees		0.00%
Other expenses		0.20%2
Total annual fund operating expenses		0.75%
Expense reimbursement/waiver		(0.17%)1
Total annual fund operating expenses after expense reimbursement/waiver		0.58%

1 Includes both management fee of 0.40% and class-specific service and supplemental support fee of 0.15% for ETF Class shares. Grantham, Mayo, Van Otterloo & Co. LLC (“GMO”) has contractually agreed to reimburse the Fund for the portion of its “Specified Operating Expenses” (as defined below) that exceeds 0.02% of the Fund’s average daily net assets. If the Fund has outstanding ETF Class shares, the reimbursement will be implemented at the share class level. “Specified Operating Expenses” means only the following expenses: audit expenses, fund accounting and administration expenses, pricing service expenses, expenses of non-investment related tax services, transfer agency expenses (excluding, in the case of Class I shares, any amounts paid for sub-transfer agency, recordkeeping and other administrative services provided by financial intermediaries for the benefit of Class I shareholders), expenses of non-investment related legal services provided to the Fund by or at the direction of GMO, federal securities law filing expenses, printing expenses, state and federal registration fees, custody expenses and exchange listing fees. GMO also has contractually agreed to waive or reduce the Fund’s management fees and service and supplemental support fees to the extent necessary to offset the management fees and service and supplemental support fees paid to GMO that are directly or indirectly borne by the Fund or a class of shares of the Fund as a result of the Fund’s direct or indirect investments in other series of GMO Trust and GMO-managed ETFs (“GMO Funds”). Management fees and service and supplemental support fees will not be waived below zero. These reimbursements and waivers will continue through at least September 30, 2027 and may not be terminated prior to this date without the action or consent of the Trust’s Board of Trustees.

2 Because ETF Class shares of the Fund are new, “Other expenses” are estimated amounts for the current fiscal year based on the expenses of Class R6 shares of the Fund.

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated, regardless of whether or not you sell your shares at the end of such periods. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses with respect to ETF Class shares remain the same as those shown in the table. The one year amounts shown reflect the expense reimbursement and waiver noted in the expense table. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

			1 Year							3 Years							5 Years							10 Years
ETF Class				$	59						$	223						$	400						$	914

Portfolio turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities. A higher portfolio turnover rate may result in higher transaction costs and, for holders of Fund shares subject to U.S. taxes, higher income taxes. These transaction costs, which are not reflected in Annual Fund operating expenses or in the Example, affect the Fund’s performance. During its fiscal year ended February 28, 2026, the Fund’s portfolio turnover rate (excluding short-term investments) was 274% of the average value of its portfolio securities. That portfolio turnover rate includes investments in U.S. Treasury Fund, which the Fund uses as a short-term investment vehicle for cash management. The Fund’s portfolio turnover rate during its fiscal year ended February 28, 2026, excluding transactions in U.S. Treasury Fund and other short-term investments, was 277% of the average value of its portfolio securities.

Principal investment strategies

The Fund invests primarily in securitized credit securities. Securitized credit securities include, but are not limited to, commercial and residential (non-agency and agency) mortgage-backed securities, small balance commercial mortgages, collateralized loan obligations, collateralized debt obligations, and securities backed by pools of receivables in various industries. The interest rates for these securities may be fixed or variable. The Fund also may invest in other fixed-income instruments, including, without limitation, bonds and other similar instruments issued or guaranteed by the U.S. government and its agencies and instrumentalities, by non-U.S. governments and their agencies and instrumentalities and by private sector entities.

The Fund also may invest in the following: interest-only, principal-only, or inverse floating rate debt; mortgage dollar rolls; securities on a when-issued, delayed delivery or forward commitment basis through the “to-be-announced” market; mortgage loans; securities of any

maturity or duration with fixed, floating, or variable rates; equity and debt securities issued by real estate investment trusts; debt securities issued by business development companies; corporate debt securities of any quality and maturity, including high-yield securities (commonly referred to as “junk bonds”); and securities that are not rated by any rating agency.

GMO utilizes both a top-down and bottom-up security selection approach. GMO allocates Fund assets among various asset classes within the structured fixed income market based on its views regarding the best value relative to what is currently available in the market. In managing the Fund’s portfolio, GMO typically analyzes a variety of factors including, among others, maturity, yield and ratings information, opportunities for price appreciation, collateral quality, credit support, structure, and market conditions. GMO attempts to diversify risks that arise from position sizes, sectors and geographies, ratings, duration, deal structure and collateral values and seeks to further limit risk of principal loss by causing the Fund to invest in securities or other instruments that it considers undervalued. To a lesser extent, GMO may use quantitative models to capitalize on price momentum across fixed income sectors. GMO does not manage the Fund to, or control the Fund’s risk relative to, any securities index or securities benchmark.

From time to time, the Fund may have some direct or indirect exposure to equities. The Fund may invest in securities of companies of any market capitalization, as well as in securities of any maturity, duration, or credit quality.

The Fund also may invest in exchange-traded funds (ETFs) and exchange-traded and over-the-counter (OTC) derivatives, including swap contracts (such as credit default swaps, swaps on securities and securities indices, total return swaps and interest rate swaps), futures contracts, forward currency contracts, currency and interest rate options, swaptions (including credit default swaptions), reverse repurchase agreements, and repurchase agreements. In addition, the Fund may lend its portfolio securities. The Fund is not limited in its use of derivatives or in the total notional value of its derivative positions. Leverage is not a principal component of the Fund’s investment strategy. However, because of its derivative positions, the Fund may at times have gross investment exposure in excess of its net assets (i.e., the Fund may be leveraged) and, therefore, may be subject to higher risk of loss during those times than if the Fund were not leveraged. The Fund’s performance can depend substantially on the performance of assets or indices underlying its derivatives even though it does not own those assets or indices.

In seeking to achieve the Fund’s investment objective, GMO may invest a significant portion of the Fund’s net assets in cash and cash equivalents.

The Fund also may invest in U.S. Treasury Fund, in money market funds unaffiliated with GMO, and directly in the types of investments typically held by money market funds. The Fund may, but is not required to, hedge part or all of its net foreign currency exposure into U.S. dollars.

The Fund’s ETF Class operates as an actively managed exchange-traded fund (“ETF”).

Performance

The bar chart and table below provide some indication of the risks of investing in the Fund by showing changes in the Fund’s annual total returns from year to year for the periods indicated and by comparing the Fund’s average annual total returns for different calendar periods with those of the Bloomberg U.S. Securitized Index and an additional comparative index intended solely to represent, in satisfaction of regulatory requirements, the overall fixed income market. The Fund’s ETF Class shares are a new class and, as of the date of this Prospectus, had not commenced operations. Returns shown are those of Class VI shares of the Fund, a mutual fund class of shares of the Fund not offered in this Prospectus, and have not been adjusted to reflect the fees and expenses attributable to ETF Class shares. Class VI shares would have substantially similar annual returns to ETF Class shares because the shares are invested in the same portfolio of securities, and the annual returns at NAV (assuming ETF Class shares are bought and sold without any premium or discount) would differ only to the extent that Class VI shares do not have the same expenses as ETF Class shares. Share classes that bear higher expenses than the share classes shown below would have lower returns. After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on your tax situation and may differ from those shown. After-tax returns shown are not relevant if you are tax-exempt or if you hold your Fund shares through tax-advantaged arrangements (such as a 401(k) plan or individual retirement account). After-tax returns are shown for Class VI shares only; after-tax returns for other classes will vary. Updated performance information for the Fund is available at https://www.gmo.com/americas/investment-capabilities/etfs/. Past performance (before and after taxes) is not an indication of future performance.

Annual Total Returns/Class VI Shares1 Years Ending December 31

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1. The Fund is the accounting and performance successor to GMO Debt Opportunities Fund, a former series of GMO Trust (the “Predecessor Fund”). The Predecessor Fund merged into the Fund (which was known as “GMO Short-Duration Collateral Fund” prior to the merger) on February 12, 2014. Performance of the Fund for periods prior to February 12, 2014 is that of the Predecessor Fund and reflects the Predecessor Fund’s annual operating expenses (0.01% lower than those of the Fund immediately following the merger). From February 12, 2014 through December 31, 2016, the Fund operated as “GMO Debt Opportunities Fund” and had the same investment objective and pursued substantially identical investment strategies as the Predecessor Fund. Effective January 1, 2017, the Fund’s investment objective changed from “positive total return” to “capital appreciation and current income” and, in conjunction with a change in the Fund’s name from “GMO Debt Opportunities Fund” to “GMO Opportunistic Income Fund,” the Fund eliminated its name policy that required the Fund to invest at least 80% of its assets in debt investments. Also effective January 1, 2017, the Fund’s investment management fee increased from 0.25% to 0.40% of the Fund’s average daily net assets. Performance of the Fund for periods prior to January 1, 2017 reflects the Fund’s annual operating expenses during those periods, and would have been lower if the current management fee were in effect.

Highest Quarter: 4.55% 2Q 2020
Lowest Quarter: -4.05% 1Q 2020
Year-to-Date: 1.34% As of 6/30/2026

Average Annual Total Returns1,2 Periods Ending December 31, 2025

	1 Year			5 Years			10 Years			Incept.
Class VI										10/03/2011
Return Before Taxes		6.47	%		4.02	%		4.28	%		4.64	%
Return After Taxes on Distributions		4.33	%		2.08	%		2.49	%		3.01	%
Return After Taxes on Distributions and Sales of Fund Shares		3.80	%		2.24	%		2.52	%		2.94	%
Bloomberg U.S. Securitized Index (returns reflect no deduction for fees, expenses, or taxes)		8.49	%		0.22	%		1.68	%		1.86	%
Bloomberg U.S. Aggregate Index (returns reflect no deduction for fees, expenses, or taxes)		7.30	%		-0.36	%		2.01	%		2.05	%

1 The Fund is the accounting and performance successor to GMO Debt Opportunities Fund, a former series of GMO Trust (the “Predecessor Fund”). The Predecessor Fund merged into the Fund (which was known as “GMO Short-Duration Collateral Fund” prior to the merger) on February 12, 2014. Performance of the Fund for periods prior to February 12, 2014 is that of the Predecessor Fund and reflects the Predecessor Fund’s annual operating expenses (0.01% lower than those of the Fund immediately following the merger). From February 12, 2014 through December 31, 2016, the Fund operated as “GMO Debt Opportunities Fund” and had the same investment objective and pursued substantially identical investment strategies as the Predecessor Fund. Effective January 1, 2017, the Fund’s investment objective changed from “positive total return” to “capital appreciation and current income” and, in conjunction with a change in the Fund’s name from “GMO Debt Opportunities Fund” to “GMO Opportunistic Income Fund,” the Fund eliminated its name policy that required the Fund to invest at least 80% of its assets in debt investments. Also effective January 1, 2017, the Fund’s investment management fee increased from 0.25% to 0.40% of the Fund’s average daily net assets. Performance of the Fund for periods prior to January 1, 2017 reflects the Fund’s annual operating expenses during those periods, and would have been lower if the current management fee were in effect.

2 On December 21, 2015, GMO changed the primary pricing source for certain fixed income asset-backed securities held by the Fund, which resulted in an increase of $0.04 to the December 21, 2015 net asset value of Class VI shares of the Fund.