GMO BENCHMARK-FREE
ALLOCATION SERIES FUND Summary Prospectus October 4, 2016

Share Class:	Class R4	Class R5	Class R6	Class PS
Ticker:	—	—	GBMRX	—

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, statement of additional information and other information about the Fund online at http://dc.gmo.com. You can also get this information at no cost by calling 877-466-7778, by sending an email request to dcops@gmo.com, or by contacting your financial intermediary. The Fund’s prospectus and statement of additional information, both dated October 4, 2016, as supplemented, are incorporated by reference into this summary prospectus.

Investment objective

Positive total return not “relative” return.

Fees and expenses

The tables below describe the fees and expenses that you may bear for each class of shares if you buy and hold shares of the Fund.

Shareholder fees

	Fees paid directly from your investment			Fees paid by the Fund
Purchase premium (as a percentage of amount invested)		0.00	%		0.20	%1
Redemption fee (as a percentage of amount redeemed)		0.00	%		0.20	%1

Annual Fund operating expenses²

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

	Class R4			Class R5			Class R6			Class PS
Management fee3		0.65	%		0.65	%		0.65	%		0.65	%
Distribution and service (12b-1) fee4		0.25	%		0.10	%		None			None
Administration fee		0.05	%		0.05	%		0.05	%		0.20	%5
Other expenses		0.16	%		0.16	%		0.16	%		0.16	%
Acquired fund fees and expenses6		0.14	%		0.14	%		0.14	%		0.14	%
Total annual fund operating expenses		1.25	%		1.10	%		1.00	%		1.15	%
Expense reimbursement7		(0.01	%)		(0.01	%)		(0.01	%)		(0.01	%)
Total annual fund operating expenses after expense reimbursement		1.24	%		1.09	%		0.99	%		1.14	%

¹ These amounts are paid to and retained by GMO Benchmark-Free Allocation Fund (“BFAF”), the underlying fund in which the Fund invests, to help offset estimated portfolio transaction and other related costs.

² The information in this table and in the Example below reflects the expenses of both the Fund and BFAF.

³ The amount reflects the management fee paid by BFAF. The Fund does not charge a management fee, but indirectly bears the management fee paid by BFAF.

⁴ Distribution and service (12b-1) fees are paid to financial intermediaries for providing sub-transfer agency, recordkeeping, and other administrative services.

⁵ Includes compensation paid to Grantham, Mayo, Van Otterloo & Co. LLC (“GMO”) for bearing expenses of sub-transfer agency, recordkeeping and related administrative services.

⁶ These indirect expenses include net expenses borne by BFAF as a result of its investment in underlying funds. These expenses represent approximately less than 0.01% of net indirect operating expenses, less than 0.01% of interest expense, 0.05% of dividend expenses on short sales, and 0.08% of purchase premium and redemption fees paid by BFAF to the underlying funds.

⁷ GMO has contractually agreed to reimburse the Fund for state registration fees to the extent that they are borne by the Fund. These reimbursements will continue through at least October 4, 2017, and may not be terminated prior to this date without the action or consent of the Fund’s Board of Trustees.

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated. The example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same as those shown in the table. The one year amounts shown

GMO BENCHMARK-FREE ALLOCATION SERIES FUND

reflect the expense reimbursement noted in the expense table and all amounts shown include the expenses of both BFAF and the Fund. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	If you sell your shares								If you do not sell your shares
	1 Year		3 Years		5 Years		10 Years		1 Year		3 Years		5 Years		10 Years
Class R4	$	167	$	477	$	810	$	1,752	$	146	$	455	$	786	$	1,724
Class R5	$	152	$	431	$	731	$	1,585	$	131	$	408	$	707	$	1,556
Class R6	$	142	$	400	$	678	$	1,472	$	121	$	377	$	654	$	1,443
Class PS	$	157	$	446	$	757	$	1,641	$	136	$	424	$	734	$	1,612

Portfolio turnover

The Fund pays transaction costs when it buys and sells securities. A higher portfolio turnover rate may result in higher transaction costs and, when Fund shares are held in a taxable account, higher 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 29, 2016, the Fund’s portfolio turnover rate (excluding short-term investments) was 27% of the average value of its portfolio.

Principal investment strategies

The Fund invests substantially all of its assets in GMO Benchmark-Free Allocation Fund (“BFAF”), a series of GMO Trust not offered in this Prospectus. BFAF invests primarily in shares of other funds managed by GMO (“GMO Funds”). The Fund’s investment objective and principal investment strategies are substantially similar to those of BFAF. Except as otherwise indicated, references to the Fund may also refer to BFAF, and references to actions undertaken or investments held by the Fund may also refer to those by BFAF. GMO serves as investment adviser for both the Fund and BFAF.

The Fund seeks annualized returns of 5% (net of fees) above the Consumer Price Index and annualized volatility (standard deviation) of 5-10%, each over a complete market cycle. GMO does not manage the Fund to, or control the Fund’s risk relative to, any securities index or securities benchmark.

GMO seeks to achieve the Fund’s investment objective by investing in asset classes GMO believes offer the most attractive return and risk opportunities. GMO uses its multi-year forecasts of returns among asset classes, together with its assessment of the relative risks of such asset classes, to determine the Fund’s allocations to various asset classes. An important component of those forecasts is GMO’s expectation that valuations ultimately revert to their fundamental fair (or intrinsic) value. The factors GMO considers and investment methods GMO uses can change over time.

The Fund is structured as a fund of funds and gains its investment exposures primarily by investing in GMO Implementation Fund (“Implementation Fund”). In addition, the Fund may invest in any other GMO Fund (together with Implementation Fund, the “underlying GMO Funds”), whether now existing or created in the future. These underlying GMO Funds may include, among others, GMO Alpha Only Fund, GMO Debt Opportunities Fund, GMO Emerging Country Debt Fund, GMO Special Opportunities Fund, and GMO SGM Major Markets Fund. Implementation Fund is permitted to invest in any asset class. The Fund also may invest directly in securities (including other underlying funds) and derivatives.

The Fund is permitted to invest (directly or through Implementation Fund or other underlying GMO Funds) in any asset class (including, for example, U.S. and non-U.S. equities (including emerging country equities), U.S. and non-U.S. fixed income securities (including emerging country debt securities), real estate, and commodities), sector, country, or region, and at times may have substantial exposure to a single asset class, sector, country, or region. In addition, the Fund is not restricted in its exposure to any particular market and may invest in securities of companies of any market capitalization, credit quality (including below investment grade securities (commonly referred to as “junk bonds”)), maturity or duration. The Fund may have indirect exposure to derivatives and short sales through its investment in Implementation Fund and the other underlying GMO Funds. GMO’s ability to shift investments within Implementation Fund and between it and the other underlying GMO Funds is not subject to any limits.

Prior to January 1, 2012, BFAF served as a principal component of a broader GMO real return strategy that also included a pooled investment vehicle with a cash-like benchmark. Since January 1, 2012, BFAF has been managed as a standalone investment.

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. GMO would not consider such investments to be “temporary defensive positions.”

The Fund also may invest in GMO U.S. Treasury Fund, in money market funds unaffiliated with GMO, or directly in the types of investments typically held by money market funds.

Benchmark-Free Allocation Series Fund may hold cash, cash equivalents, and/or U.S. government securities to manage cash inflows and outflows as a result of shareholder purchases and redemptions.

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Principal risks of investing in the Fund

The value of the Fund’s shares changes with the value of the Fund’s investments. Many factors can affect this value, and you may lose money by investing in the Fund. References to investments include those held directly by the Fund and indirectly through the Fund’s investments in underlying funds (including underlying GMO Funds). Because the Fund invests substantially all of its assets in BFAF, the most significant risks of investing in the Fund are the risks to which the Fund is exposed through BFAF, which include those outlined in the following brief summary of principal risks. Some of the underlying funds of BFAF are non-diversified investment companies under the Investment Company Act of 1940, as amended, and therefore a decline in the market price of a particular security held by those underlying funds may affect the performance of those underlying funds more than if they were diversified investment companies. In addition to the risks to which the Fund is exposed through its investment in BFAF, the Fund is subject to the risk that cash flows into or out of the Fund will cause its performance to be worse than the performance of BFAF.

• Management and Operational Risk – The Fund runs the risk that GMO’s investment techniques will fail to produce desired results (including the annualized volatility and the annualized returns above the Consumer Price Index that the Fund seeks). In addition, the Fund could produce results consistent with annualized volatility over a complete market cycle yet experience shorter periods of significantly higher or lower volatility. GMO often uses quantitative models as part of its investment process. GMO’s models are not necessarily predictive of future market events and use simplifying assumptions that can limit their effectiveness. In addition, the data on which the models are based is subject to limitations (e.g., inaccuracies, staleness) that could adversely affect the Fund’s performance. The Fund also runs the risk that GMO’s assessment of an investment (including a company’s fundamental fair (or intrinsic) value) may be wrong or that deficiencies in GMO’s or another service provider’s internal systems or controls will cause losses for the Fund or impair Fund operations.

• Market Risk – Equities – The market price of an equity may decline due to factors affecting the issuer, its industry or the economy and equity markets generally. If an underlying fund purchases an equity for less than its fundamental fair (or intrinsic) value as determined by GMO, the Fund runs the risk that the market price of the equity will not appreciate or will decline due to GMO’s incorrect assessment of the equity’s fundamental fair (or intrinsic) value. An underlying fund also may purchase equities that typically trade at higher multiples of current earnings than other securities, and the market prices of these equities often are more sensitive to changes in future earnings expectations than the market prices of equities trading at lower multiples. Declines in stock market prices generally are likely to reduce the net asset value of the Fund’s shares.

• Non-U.S. Investment Risk – The market prices of many non-U.S. securities fluctuate more than those of U.S. securities. Many non-U.S. securities markets are less stable, smaller, less liquid, and less regulated than U.S. securities markets, and the cost of trading in those markets often is higher than in U.S. securities markets. Transactions in non-U.S. securities generally involve higher commission rates, transfer taxes, and custodial costs than similar transactions in U.S. securities. In addition, the Fund may be subject to non-U.S. taxes, including potentially on a retroactive basis, on (i) capital gains it realizes or dividends, interest, or other amounts it realizes or accrues in respect of non-U.S. investments; (ii) transactions in those investments; and (iii) repatriation of proceeds generated from the sale or other disposition of those investments. Also, the Fund needs a license to invest directly in many non-U.S. securities markets, and the Fund is subject to the risk that it could not invest if its license were terminated or suspended. In some non-U.S. securities markets, prevailing custody and trade settlement practices (e.g., the requirement to pay for securities prior to receipt) expose the Fund to credit and other risks. Further, adverse changes in investment regulations, capital requirements or exchange controls could adversely affect the value of the Fund’s investments. These and other risks (e.g., nationalization, expropriation or other confiscation of assets of non-U.S. issuers) tend to be greater for investments in companies tied economically to emerging countries, the economies of which may be predominantly based on only a few industries or dependent on revenues from particular commodities and which often are more volatile than the economies of developed countries.

• Market Risk – Fixed Income Investments – The market price of a fixed income investment can decline due to market-related factors, including rising interest rates and widening credit spreads, or decreased liquidity stemming from the market’s uncertainty about the value of a fixed income investment (or class of fixed income investments).

• Derivatives and Short Sales Risk – The use of derivatives involves the risk that their value may not change as expected relative to changes in the value of the underlying assets, rates, or indices. Derivatives also present other risks, including market risk, illiquidity risk, currency risk, credit risk, and counterparty risk. The market price of an option is affected by many factors, including changes in the market prices or dividend rates of underlying securities (or in the case of indices, the securities in such indices); the time remaining before expiration; changes in interest rates or exchange rates; and changes in the actual or perceived volatility of the relevant stock market and underlying securities. The Fund may create short investment exposure by taking a derivative position in which the value of the derivative moves in the opposite direction from the price of an underlying investment, pool of investments, index or currency. The risks of loss associated with derivatives that provide short investment exposure and short sales of securities are theoretically unlimited.

• Futures Contracts Risk – The risk of loss to the Fund resulting from its use of futures contracts is potentially unlimited. Futures markets are highly volatile and the use of futures contracts may increase the volatility of the Fund’s net asset value. A liquid secondary market may not exist for any particular futures contract at any particular time and the Fund might be unable to effect closing transactions to terminate its exposure to the contract. If the Fund uses futures contracts for hedging purposes, it runs the risk of imperfect correlation between changes in the prices of the contracts and changes in the securities, index, or other asset underlying the contracts or movements

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GMO BENCHMARK-FREE ALLOCATION SERIES FUND

in the prices of the Fund’s investments that are the subject of the hedge. In addition, the Fund may be delayed or prevented from recovering margin or other amounts deposited with a futures commission merchant or futures clearinghouse. Foreign futures contracts may be less liquid and more volatile than U.S. contracts.

• Credit Risk – The Fund runs the risk that the issuer or guarantor of a fixed income investment or the obligor of an obligation underlying an asset-backed security will be unable or unwilling to satisfy its obligation to pay principal and interest or otherwise to honor its obligations in a timely manner. The market price of a fixed income investment will normally decline as a result of the issuer’s, guarantor’s, or obligor’s failure to meet its payment obligations, or in anticipation of such failure. Below investment grade securities have speculative characteristics, and changes in economic conditions or other circumstances are more likely to impair the ability of issuers of those securities to make principal and interest payments than is the case with issuers of investment grade securities.

• Currency Risk – Fluctuations in exchange rates can adversely affect the market value of the Fund’s foreign currency holdings and investments denominated in foreign currencies.

• Fund of Funds Risk – The Fund is indirectly exposed to all of the risks of an investment in BFAF and the underlying funds (including underlying GMO Funds) in which it invests, including the risk that BFAF and those underlying funds will not perform as expected.

• Commodities Risk – Commodity prices can be extremely volatile, and exposure to commodities can cause the net asset value of the Fund’s shares to decline or fluctuate in a rapid and unpredictable manner.

• Merger Arbitrage Risk – If the Fund purchases securities in anticipation of a proposed merger, exchange offer, tender offer, or other similar transaction and that transaction later appears unlikely to be consummated or, in fact, is not consummated or is delayed, the market prices of the securities purchased by the Fund may decline sharply, resulting in losses to the Fund. The risk/reward payout of merger arbitrage strategies typically is asymmetric, as the losses in failed transactions often far exceed the gains in successful transactions. Merger arbitrage strategies are subject to the risk of overall market movements, and the Fund may experience losses even if a transaction is consummated.

• Illiquidity Risk – Low trading volume, lack of a market maker, large position size, or legal restrictions may limit or prevent the Fund or an underlying fund from selling particular securities or closing derivative positions at desirable prices.

• Leveraging Risk – The use of reverse repurchase agreements and other derivatives and securities lending creates leverage. Leverage increases the Fund’s losses when the value of its investments (including derivatives) declines.

• Counterparty Risk – The Fund runs the risk that the counterparty to a derivatives contract, a clearing member used by the Fund to hold a cleared derivatives contract, or a borrower of the Fund’s securities will be unable or unwilling to make timely settlement payments, return the Fund’s margin or otherwise honor its obligations.

• Small Company Risk – Smaller companies may have limited product lines, markets, or financial resources, may lack the competitive strength of larger companies, may have inexperienced managers or may depend on a few key employees. The securities of companies with smaller market capitalizations often are less widely held and trade less frequently and in lesser quantities, and their market prices often fluctuate more, than the securities of companies with larger market capitalizations.

• Market Disruption and Geopolitical Risk – Geopolitical and other events may disrupt securities markets and adversely affect global economies and markets. Those events, as well as other changes in non-U.S. and U.S. economic and political conditions, could adversely affect the value of the Fund’s investments.

• Market Risk – Asset-Backed Securities – The market price of fixed income investments with complex structures, such as asset-backed securities, can decline due to a variety of factors, including market uncertainty about their credit quality and the reliability of their payment streams. Payment streams associated with asset-backed securities held by the Fund depend on many factors (e.g., the cash flow generated by the assets backing the securities, the deal structure, the creditworthiness of any credit-support provider, and the reliability of various other service providers with access to the payment stream), and a problem in any one of these factors can lead to a reduction in the payment stream GMO expected the Fund to receive at the time the Fund purchased the asset-backed security.

• Focused Investment Risk – Investments focused in countries, regions, sectors, industries, or issuers that are subject to the same or similar risk factors and investments whose prices are closely correlated are subject to greater overall risk than investments that are more diversified or whose prices are not as closely correlated.

• Large Shareholder Risk – To the extent that a large number of shares of the Fund is held by a single shareholder (e.g., an institutional investor or financial intermediary), the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its Fund shares will require the Fund to sell securities at disadvantageous prices or otherwise disrupt the Fund’s operations.

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GMO BENCHMARK-FREE ALLOCATION SERIES FUND

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 Barclays U.S. Treasury Inflation Notes: 1-10 Year Index and the Consumer Price Index. The Fund commenced operations on January 24, 2013. Returns prior to the date the Fund commenced operations are those of BFAF (Class III shares), adjusted to reflect the estimated gross operating expenses (on a percentage basis) that were expected to be borne by shareholders of each class of shares of the Fund as of the commencement of the Fund’s operations. The returns shown for periods prior to January 1, 2012 are for Class III shares of BFAF under BFAF’s prior fee arrangement. Under BFAF’s current fee arrangement, the returns for periods prior to January 1, 2012 would have been lower. The effect of purchase premiums and redemption fees paid by the Fund to BFAF are not reflected in the bar chart or table below for portions of the periods prior to the date on which the Fund commenced operations. If the effect of these payments were reflected, returns for periods prior to the date on which the Fund commenced operations would be less than those shown. 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 R4 shares only; after-tax returns for other classes will vary. Updated performance information for the Fund and BFAF is available at www.gmo.com. Past performance (before and after taxes) is not an indication of future performance.

Annual Total Returns/Class R4 Shares

Years Ending December 31

Highest Quarter: 9.10% (2Q2009)

Lowest Quarter: – 6.98% (4Q2008)

Year-to-Date (as of 6/30/16): 0.82%

Average Annual Total Returns

Periods Ending December 31, 2015

	1 Year		5 Years		10 Years		Inception
								7/23/03	*
Class R4
Return Before Taxes		– 4.52%		3.77%		5.28%		8.44%
Return After Taxes on Distributions		– 5.51%		2.93%		3.65%		6.62%
Return After Taxes on Distributions and Sale of Fund Shares		– 2.13%		2.69%		3.78%		6.40%
Class R5
Return Before Taxes		– 4.37%		3.93%		5.44%		8.60%
Class R6
Return Before Taxes		– 4.26%		4.04%		5.55%		8.72%
Class PS
Return Before Taxes		– 4.42%		3.88%		5.39%		8.55%
Barclays U.S. Treasury Inflation Notes: 1-10 Year Index (reflects no deduction for fees, expenses, or taxes)		– 0.52%		1.64%		3.51%		3.76%
Consumer Price Index (reflects no deduction for fees, expenses, or taxes)		0.72%		1.55%		1.87%		2.10%

* Inception date for BFAF (Class III shares).

Management of the Fund

Investment Adviser: Grantham, Mayo, Van Otterloo & Co. LLC

Investment Team and Senior Members of GMO primarily responsible for portfolio management of the Fund:

Investment Team	Senior Member (Length of Service with Fund)	Title
Asset Allocation	Ben Inker (since the Fund’s inception in 2013)	Co-Head, Asset Allocation Team and Co-Head, Developed Fixed Income Team, GMO.
Asset Allocation	Sam Wilderman* (since the Fund’s inception in 2013)	Co-Head, Asset Allocation Team and Co-Head, Developed Fixed Income Team, GMO.

* As part of a transition plan, Mr. Wilderman will be reducing his involvement in the day-to-day management of the Fund through December 31, 2016, after which he will no longer serve as the Co-Head of the Asset Allocation and Developed Fixed Income Teams or be involved in the management of the Fund’s portfolio.

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GMO BENCHMARK-FREE ALLOCATION SERIES FUND

Purchase and sale of Fund shares

In general, shareholders of record may purchase and redeem shares of the Fund on days when the New York Stock Exchange is open for business. Investors purchasing shares of the Fund through an intermediary (e.g., retirement plan participants purchasing through a retirement plan administrator) should contact their intermediary to purchase and redeem shares of the Fund. There is no minimum initial investment for retirement plan participants and similar investors purchasing shares of the Fund through an intermediary. The minimum initial investment for shareholders of record that establish an omnibus account with the Fund is $10 million, but that amount may be waived or reduced at the discretion of GMO. There is no minimum subsequent investment for shareholders of the Fund. The Trust in its sole discretion and without notice may change the minimum initial or subsequent investment requirements for any class of shares of the Fund.

Tax information

The Fund expects to distribute net investment income and net realized capital gains, if any, to shareholders. These distributions generally are taxable to shareholders whose Fund shares are held in a taxable account as ordinary income and/or capital gain. Retirement plan participants investing in the Fund through a tax-qualified retirement plan generally will not be subject to tax on these Fund distributions so long as their Fund shares remain in the qualified plan. Retirement plan participants, however, may be taxed upon withdrawals from their qualified plan. Retirement plan participants and others investing in the Fund through another type of tax-advantaged plan or account should consult with their tax adviser and plan administrator or other designated financial intermediary for information regarding the specific U.S. federal income tax consequences to them of receiving Fund distributions and their Fund investment more generally.

Financial intermediary compensation

If you purchase shares of the Fund through a broker, agent, or other financial intermediary (such as a bank), the Fund or GMO may pay that party for services relating to Fund shares. These payments may create a conflict of interest by influencing the broker or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or consult your financial intermediary’s website for more information.

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