N-CSR

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-22564

GMO Series Trust

(Exact name of the registrant as specified in charter)

40 Rowes Wharf, Boston, MA 02110

(Address of principal executive offices) (Zip Code)

Sheppard N. Burnett, Chief Executive Officer, 40 Rowes Wharf, Boston, MA 02110

(Name and address of agent for services)

Registrant’s telephone number, including area code: 617-346-7646

Date of fiscal year end: 02/28/17

Date of reporting period: 02/28/17

Item 1. Reports to Stockholders.

The annual reports for each series of the registrant for the period ended February 28, 2017 are filed herewith.

GMO Series Trust

Annual Report

February 28, 2017

Benchmark-Free Allocation Series Fund

Emerging Countries Series Fund

Global Asset Allocation Series Fund

Global Equity Allocation Series Fund

International Developed Equity Allocation Series Fund

International Equity Allocation Series Fund

For a free copy of the Funds’ proxy voting guidelines, shareholders may call 1-617-346-7646 (collect) or visit the Securities and Exchange Commission’s website at www.sec.gov. Information regarding how the Funds voted proxies relating to portfolio securities during the most recent 12-month period ended June 30 is available on GMO’s website www.dc.gmo.com or on the Securities and Exchange Commission’s website at www.sec.gov.

The Funds file their complete schedule of portfolio holdings with the Securities and Exchange Commission for the first and third quarter of each fiscal year on Form N-Q, which is available on the Commission’s website at www.sec.gov. The Funds’ Form N-Q may be reviewed and copied at the Commission’s Public Reference Room in Washington, D.C. Information on the operation of the Public Reference Room may be obtained by calling 1-800-SEC-0330.

This report is prepared for the general information of shareholders. It is authorized for distribution to prospective investors only when preceded or accompanied by a prospectus for GMO Series Trust, which contains a complete discussion of the risks associated with an investment in these Funds and other important information. The GMO Series Trust prospectus can be obtained at www.dc.gmo.com.

An investment in the Funds is subject to risk, including the possible loss of the principal amount invested. There can be no assurance that the Funds will achieve the stated investment objectives. Please see the Funds’ prospectus regarding specific risks for each Fund. General risks may include: market risk, management and operational risk, non-U.S. investment risk, small company risk and derivatives risk.

The Funds are distributed by Funds Distributor LLC. Funds Distributor LLC is not affiliated with GMO.

TABLE OF CONTENTS

Benchmark-Free Allocation Series Fund
Management Discussion and Analysis of Fund Performance	2
Performance Graph	2
Investment Concentration Summary	3
Schedule of Investments	4
Emerging Countries Series Fund
Management Discussion and Analysis of Fund Performance	5
Performance Graph	5
Investment Concentration Summary	6
Schedule of Investments	7
Global Asset Allocation Series Fund
Management Discussion and Analysis of Fund Performance	8
Performance Graph	8
Investment Concentration Summary	9
Schedule of Investments	10
Global Equity Allocation Series Fund
Management Discussion and Analysis of Fund Performance	11
Performance Graph	11
Investment Concentration Summary	12
Schedule of Investments	13
International Developed Equity Allocation Series Fund
Management Discussion and Analysis of Fund Performance	14
Performance Graph	14
Investment Concentration Summary	15
Schedule of Investments	16
International Equity Allocation Series Fund
Management Discussion and Analysis of Fund Performance	17
Performance Graph	17
Investment Concentration Summary	18
Schedule of Investments	19
Fund Financial Statements:
Statements of Assets and Liabilities	20
Statements of Operations	21
Statements of Changes in Net Assets	23
Financial Highlights	26
Notes to Financial Statements	32
Report of Independent Registered Public Accounting Firm	59
Fund Expenses	60
Tax Information	61
Trustees and Officers	62

GMO Benchmark-Free Allocation Series Fund

(A Series of GMO Series Trust)

Portfolio Management

Day-to-day management of the Fund’s portfolio is the responsibility of the Asset Allocation team at Grantham, Mayo, Van Otterloo & Co. LLC.

Management Discussion and Analysis of Fund Performance

Although GMO does not manage the Fund to, or control the Fund’s risk relative to, any securities index or securities benchmark, a discussion of the Fund’s performance relative to the Consumer Price Index (“CPI”) is included for comparative purposes.

Class R6 shares of GMO Benchmark-Free Allocation Series Fund returned +11.41% (net) for the fiscal year ended February 28, 2017, as compared with +2.84% for the CPI.

The Fund’s exposure to equities, particularly in emerging markets, was the primary driver of the strong performance. The Fund’s exposure to fixed income also contributed, as all of the strategies enjoyed positive performance, with emerging debt and distressed debt being most noteworthy. Alternative strategies also added value in aggregate, although one of the strategies in this grouping, relative value interest rates & FX, posted modest negative returns. Cash and short duration bond holdings had a negative impact on performance, largely due to the considerable increase in yields in the US in the fourth quarter of 2016.

Because some of the securities and instruments held directly or indirectly by the Fund had positive fair value adjustments at the beginning or end of the fiscal year (and the performance of indices are not fair valued), the Fund’s absolute and relative performance is higher than it otherwise would have been in the absence of such fair value adjustments.

The views expressed herein are exclusively those of Grantham, Mayo, Van Otterloo & Co. LLC as of the date of this report and are subject to change. GMO disclaims any responsibility to update such views. They are not meant as investment advice. References to specific securities are not recommendations of such securities and may not be representative of any GMO portfolio’s current or future investments.

Comparison of Change in Value of a $10,000,000 Investment in

GMO Benchmark-Free Allocation Series Fund Class R6 Shares and the Consumer Price Index

As of February 28, 2017

Performance data quoted represents past performance and is not indicative of future results. The investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Current performance data may be lower or higher than the performance data provided herein. To obtain performance information up to the most recent month-end, visit www.gmo.com. Performance data shown above for GMO Benchmark-Free Allocation Series Fund (the “Fund”) reflect the performance data of GMO Benchmark-Free Allocation Fund (the “Institutional Fund”) through January 24, 2013 (the commencement date of the Fund), re-stated to reflect the additional fees and expenses of the Fund. Performance data shown above for the Fund is net of all fees after reimbursement from the Manager. Returns would have been lower had certain expenses not been reimbursed during the periods shown and do not include the effect of taxes on distributions and redemptions. All information is unaudited.

The Fund invests substantially all of its assets in shares of the Institutional Fund. Prior to January 1, 2012, the Institutional Fund served as a principal component of a broader GMO real return strategy. Beginning on January 1, 2012, the Institutional Fund has been managed as a standalone investment vehicle.

2

GMO Benchmark-Free Allocation Series Fund

(A Series of GMO Series Trust)

Investment Concentration Summary

February 28, 2017 (Unaudited)

Asset Class Summary&	% of Total Net Assets
Common Stocks		42.8	%
Debt Obligations		40.5
Short-Term Investments		13.3
Preferred Stocks		1.9
Futures Contracts		0.1
Options Purchased		0.1
Loan Participations		0.1
Rights/Warrants		0.1
Forward Currency Contracts		0.0	^
Loan Assignments		0.0	^
Swap Contracts		(0.0	)^
Reverse Repurchase Agreements		(0.0	)^
Written/Credit Linked Options		(0.1	)
Securities Sold Short		(1.3	)
Other		2.5
		100.0	%
Country/Region Summary¤	Debt Obligations as a % of Total Net Assets
United States		11.9	%
Other Emerging		2.4	†
Mexico		1.3
Other Developed		0.8	‡
Euro Region		(0.1	)#
Japan		(1.4	)
United Kingdom		(2.0	)
		12.9	%
Country/Region Summary¤	Equity Investments as a % of Total Net Assets
United States		10.3	%
China		5.9
Other Emerging		4.2	†
South Korea		3.1
Other Developed		3.1	‡
Japan		2.9
Taiwan		2.7
Brazil		2.3
United Kingdom		2.1
Germany		1.6
South Africa		1.4
India		1.3
France		1.2
Netherlands		1.2
Switzerland		1.1
		44.4	%

& The table above incorporates aggregate indirect asset class exposure resulting from investments in shares of a series of GMO Trust (the “Institutional Fund”) and the series of GMO Trust in which the Institutional Fund invests (collectively referred to as the “underlying funds”), if any. Derivative financial instruments, if any, are based on

market values or unrealized appreciation/depreciation rather than notional amounts.

¤ The table above incorporates aggregate indirect country exposure associated with investments in the Institutional Fund and underlying funds, if any. The table excludes short-term investments, if any. The table includes exposure through the use certain derivative financial instruments and excludes exposure through certain currency linked derivatives such as forward currency contracts and currency options, if any. The table is based on duration adjusted net exposures (both investments and derivatives), taking into account the market value of securities and the notional amounts of swaps and other derivative financial instruments. For example, U.S. asset-backed securities may represent a relatively small percentage due to their short duration, even though they represent a large percentage of market value (direct and indirect). Duration is based on GMO’s models. The greater the duration of a bond, the greater its contribution to the concentration percentage. Credit default swap exposures are factored into the duration adjusted exposure using the reference security and applying the same methodology to that security. The tables are not normalized, thus, due to the exclusions listed above and negative exposures, which may be attributable to derivatives or short sales, if any, the tables may not total to 100%.

† “Other Emerging” is comprised of emerging countries that each represent between (1.0)% and 1.0% of Total Net Assets.

‡ “Other Developed” is comprised of developed countries that each represent between (1.0)% and 1.0% of Total Net Assets.

# “Euro Region” is comprised of derivative financial instruments attributed to the Eurozone and not a particular country.

^ Rounds to 0.0%.

3

GMO Benchmark-Free Allocation Series Fund

(A Series of GMO Series Trust)

Schedule of Investments

(showing percentage of total net assets)

February 28, 2017

Shares		Description	Value ($)
		MUTUAL FUNDS — 98.5%
		Affiliated Issuers — 98.5%
	11,368,299	GMO Benchmark-Free Allocation Fund, Class III		293,074,743
		TOTAL MUTUAL FUNDS (Cost $299,029,816)		293,074,743
		TOTAL INVESTMENTS — 98.5% (Cost $299,029,816)		293,074,743
		Other Assets and Liabilities (net) — 1.5%		4,545,069
		TOTAL NET ASSETS — 100.0%		$297,619,812

See accompanying notes to the financial statements.

4

GMO Emerging Countries Series Fund

(A Series of GMO Series Trust)

Portfolio Management

Day-to-day management of the Fund’s portfolio is the responsibility of the Emerging Markets Equity team at Grantham, Mayo, Van Otterloo & Co. LLC.

Management Discussion and Analysis of Fund Performance

Class R6 shares of GMO Emerging Countries Series Fund returned +35.61% (net) for the fiscal year ended February 28, 2017, as compared with +30.27% for the Fund’s benchmark, the S&P/IFCI Composite Index.

Country-sector allocation contributed to the Fund’s relative returns for the fiscal year. The Fund’s overweight in Russia Financials and India Financials added to relative performance. The Fund’s overweight in Korea Consumer Discretionary and Turkey Telecommunications detracted from relative performance.

Stock selection was additive during the fiscal year. The Fund’s stock selection in Korea Information Technology and Brazil Financials helped relative performance, while the stock selection in Russia Energy and India Materials hurt relative performance.

Because some of the securities and instruments held directly or indirectly by the Fund had positive fair value adjustments at the beginning or end of the fiscal year (and the performance of indices are not fair valued), the Fund’s absolute and relative performance is higher than it otherwise would have been in the absence of such fair value adjustments.

The views expressed herein are exclusively those of Grantham, Mayo, Van Otterloo & Co. LLC as of the date of this report and are subject to change. GMO disclaims any responsibility to update such views. They are not meant as investment advice. References to specific securities are not recommendations of such securities and may not be representative of any GMO portfolio’s current or future investments.

Comparison of Change in Value of a $10,000,000 Investment in

GMO Emerging Countries Series Fund Class R6 Shares and the S&P/IFCI Composite Index

As of February 28, 2017

Performance data quoted represents past performance and is not indicative of future results. The investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Current performance data may be lower or higher than the performance data provided herein. To obtain performance information up to the most recent month-end, visit www.gmo.com. Performance data shown above for GMO Emerging Countries Series Fund (the “Fund”) reflect the performance data of GMO Emerging Countries Fund (the “Institutional Fund”) through May 2, 2014 (the commencement date of the Fund), re-stated to reflect the additional fees and expenses of the Fund. Performance data shown above for the Fund is net of all fees after reimbursement from the Manager. Returns would have been lower had certain expenses not been reimbursed during the periods shown and do not include the effect of taxes on distributions and redemptions. All information is unaudited.

The Fund invests substantially all of its assets in shares of the Institutional Fund.

For S&P disclaimers please visit http://www.gmo.com/America/_Disclaimers/_BenchmarkDisclaimers.htm.

5

GMO Emerging Countries Series Fund

(A Series of GMO Series Trust)

Investment Concentration Summary

February 28, 2017 (Unaudited)

Asset Class Summary&	% of Total Net Assets
Common Stocks		89.6	%
Preferred Stocks		4.8
Investment Funds		3.1
Short-Term Investments		0.2
Rights/Warrants		0.0	^
Futures Contracts		(0.0	)^
Other		2.3
		100.0	%
Country/Region Summary¤	% of Investments
Taiwan		22.6	%
China		21.1
South Korea		17.1
India		10.9
Russia		7.4
Turkey		6.3
United States		3.6	¥
Brazil		2.9
Thailand		2.3
Mexico		1.4
Indonesia		0.7
Greece		0.7
United Kingdom		0.6	¥
Philippines		0.6
South Africa		0.5
Qatar		0.2
Malaysia		0.2
United Arab Emirates		0.2
Vietnam		0.2
Egypt		0.2
Chile		0.1
Belgium		0.1	¥
Czech Republic		0.1
Poland		0.0	^
		100.0	%

Industry Group Summary	% of Equity Investments#
Banks		24.5	%
Technology Hardware & Equipment		16.8
Telecommunication Services		14.1
Automobiles & Components		7.7
Materials		6.8
Software & Services		6.0
Semiconductors & Semiconductor Equipment		5.1
Energy		4.4
Diversified Financials		2.8
Food, Beverage & Tobacco		2.4
Insurance		2.4
Real Estate		1.3
Transportation		0.9
Consumer Services		0.8
Utilities		0.7
Food & Staples Retailing		0.7
Consumer Durables & Apparel		0.6
Capital Goods		0.5
Household & Personal Products		0.5
Health Care Equipment & Services		0.3
Media		0.3
Pharmaceuticals, Biotechnology & Life Sciences		0.3
Retailing		0.1
		100.0	%

& The table above incorporates aggregate indirect asset class exposure resulting from investments in shares of a series of GMO Trust (the “Institutional Fund”) and the series of GMO Trust in which the Institutional Fund invests (collectively referred to as the “underlying funds”), if any. Derivative financial instruments, if any, are based on market values or unrealized appreciation/depreciation rather than notional amounts.

¤ The table above incorporates aggregate indirect country exposure associated with investments in the Institutional Fund and underlying funds. The table excludes short-term investments, if any. The table excludes exposure through other derivative financial instruments, if any. The table takes into account the market value of securities and options and the notional amounts of swap contracts and other derivative financial instruments, if any.

¥ Includes companies that derive more than 50% of their revenues or profits from emerging markets.

# Equity investments may consist of common stocks and other stock related securities, such as preferred stocks, if any. This table excludes exposure to derivative contracts, short-term investments, mutual funds and investment funds, if any. For a summary of these exposures, if any, see the Schedule of Investments of the Institutional Fund.

^ Rounds to 0.0%.

6

GMO Emerging Countries Series Fund

(A Series of GMO Series Trust)

Schedule of Investments

(showing percentage of total net assets)

February 28, 2017

Shares		Description	Value ($)
		MUTUAL FUNDS — 99.0%
		Affiliated Issuers — 99.0%
	466,622	GMO Emerging Countries Fund, Class III		12,626,796
		TOTAL MUTUAL FUNDS (Cost $12,916,021)		12,626,796
		TOTAL INVESTMENTS — 99.0% (Cost $12,916,021)		12,626,796
		Other Assets and Liabilities (net) — 1.0%		128,163
		TOTAL NET ASSETS — 100.0%		$12,754,959

See accompanying notes to the financial statements.

7

GMO Global Asset Allocation Series Fund

(A Series of GMO Series Trust)

Portfolio Management

Day-to-day management of the Fund’s portfolio is the responsibility of the Asset Allocation team at Grantham, Mayo, Van Otterloo & Co. LLC.

Management Discussion and Analysis of Fund Performance

Class R6 shares of GMO Global Asset Allocation Series Fund returned +12.87% (net) for the fiscal year ended February 28, 2017, as compared with +14.51% for the Fund’s benchmark, the GMO Global Asset Allocation Index (65% MSCI All Country World Index (“ACWI”) and 35% Barclays U.S. Aggregate Index).

The Fund’s underweight in equities, compared to the benchmark, detracted from relative performance. Within equities, the overweighting to emerging markets was helpful, but the overweighting to developed ex-US stocks and the underweighting to the US hurt relative performance. The Fund’s exposure to alternative strategies detracted from relative performance, as they significantly underperformed the very strong returns generated by equity markets. The underweighting to fixed income was beneficial to performance, and the Fund also enjoyed strong performance within fixed income, driven primarily by emerging market debt. Our exposure to cash/cash plus detracted from relative performance.

Because some of the securities and instruments held directly or indirectly by the Fund had positive fair value adjustments at the beginning or end of the fiscal year (and the performance of indices are not fair valued), the Fund’s absolute and relative performance is higher than it otherwise would have been in the absence of such fair value adjustments.

The views expressed herein are exclusively those of Grantham, Mayo, Van Otterloo & Co. LLC as of the date of this report and are subject to change. GMO disclaims any responsibility to update such views. They are not meant as investment advice. References to specific securities are not recommendations of such securities and may not be representative of any GMO portfolio’s current or future investments.

Comparison of Change in Value of a $10,000,000 Investment in

GMO Global Asset Allocation Series Fund Class R6 Shares and the GMO Global Asset Allocation Index

As of February 28, 2017

Performance data quoted represents past performance and is not indicative of future results. The investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Current performance data may be lower or higher than the performance data provided herein. To obtain performance information up to the most recent month-end, visit www.gmo.com. Performance data shown above for GMO Global Asset Allocation Series Fund (the “Fund”) reflect the performance data of GMO Global Asset Allocation Fund (the “Institutional Fund”) through July 31, 2012 (the commencement date of the Fund), re-stated to reflect the additional fees and expenses of the Fund. Performance data shown above for the Fund is net of all fees after reimbursement from the Manager. Returns would have been lower had certain expenses not been reimbursed during the periods shown and do not include the effect of taxes on distributions and redemptions. All information is unaudited.

The Fund invests substantially all of its assets in shares of the Institutional Fund.

* The GMO Global Asset Allocation Index is comprised of 48.75% S&P 500 Index, 16.25% MSCI ACWI ex USA and 35% Barclays U.S. Aggregate Index through 3/31/2007, and 65% MSCI ACWI (All CountryWorld Index) and 35% Barclays U.S. Aggregate Index thereafter.

MSCI data may not be reproduced or used for any other purpose. MSCI provides no warranties, has not prepared or approved this report, and has no liability hereunder.

For S&P disclaimers please visit http://www.gmo.com/America/_Disclaimers/_BenchmarkDisclaimers.htm.

8

GMO Global Asset Allocation Series Fund

(A Series of GMO Series Trust)

Investment Concentration Summary

February 28, 2017 (Unaudited)

Asset Class Summary&	% of Total Net Assets
Common Stocks		51.9	%
Debt Obligations		24.9
Short-Term Investments		16.3
Mutual Funds		5.1
Preferred Stocks		0.8
Investment Funds		0.1
Loan Participations		0.1
Futures Contracts		0.1
Rights/Warrants		0.0	^
Options Purchased		0.0	^
Loan Assignments		0.0	^
Forward Currency Contracts		(0.0	)^
Written/Credit Linked Options		(0.0	)^
Reverse Repurchase Agreements		(0.0	)^
Swap Contracts		(0.1	)
Securities Sold Short		(0.1	)
Other		0.9
		100.0	%
Country/Region Summary¤	Debt Obligations as a % of Investments
United States		15.0	%
Other Emerging		2.0	†
Mexico		1.2
Euro Region		(0.1	)#
Other Developed		(0.3	)‡
United Kingdom		(1.5	)
		16.3	%
Country/Region Summary¤	Equity Investments as a % of Investments
United States		16.8	%
Japan		5.9
Other Developed		4.5	‡
United Kingdom		4.3
Taiwan		4.0
Other Emerging		3.7	†
China		3.1
South Korea		2.5
France		2.1
Germany		2.0
India		1.9
Switzerland		1.4
Australia		1.4
Hong Kong		1.0
Euro Region		(0.0	)#^
		54.6	%

& The table above incorporates aggregate indirect asset class exposure resulting from investments in shares of a series of GMO Trust (the “Institutional Fund”) and the series of GMO Trust in which the Institutional Fund invests (collectively referred to as the “underlying

funds”), if any, except for GMO Alpha Only Fund. Derivative financial instruments, if any, are based on market values or unrealized appreciation/depreciation rather than notional amounts.

¤ The table above incorporates aggregate indirect country exposure associated with investments in the Institutional Fund and underlying funds, if any. The table excludes short-term investments, if any. The table includes exposure through the use of certain derivative financial instruments and excludes exposure through certain currency linked derivatives such as forward currency contracts and currency options, if any. The table is based on duration adjusted net exposures (both investments and derivatives), taking into account the market value of securities and the notional amounts of swaps and other derivative financial instruments. For example, U.S. asset-backed securities may represent a relatively small percentage due to their short duration, even though they represent a large percentage of market value (direct and indirect). Duration is based on GMO’s models. The greater the duration of a bond, the greater its contribution to the concentration percentage. Credit default swap exposures are factored into the duration adjusted exposure using the reference security and applying the same methodology to that security. The tables are not normalized, thus, due to the exclusions listed above and negative exposures, which may be attributable to derivatives or short sales, if any, the tables may not total to 100%.

† “Other Emerging” is comprised of emerging countries that each represent between (1.0)% and 1.0% of Investments.

‡ “Other Developed” is comprised of developed countries that each represent between (1.0)% and 1.0% of Investments.

# “Euro Region” is comprised of derivative financial instruments attributed to the Eurozone and not a particular country.

^ Rounds to 0.0%.

9

GMO Global Asset Allocation Series Fund

(A Series of GMO Series Trust)

Schedule of Investments

(showing percentage of total net assets)

February 28, 2017

Shares		Description	Value ($)
		MUTUAL FUNDS — 98.8%
		Affiliated Issuers — 98.8%
	5,844,827	GMO Global Asset Allocation Fund, Class III		178,150,315
		TOTAL MUTUAL FUNDS (Cost $196,323,255)		178,150,315
		TOTAL INVESTMENTS — 98.8% (Cost $196,323,255)		178,150,315
		Other Assets and Liabilities (net) — 1.2%		2,189,502
		TOTAL NET ASSETS — 100.0%		$180,339,817

See accompanying notes to the financial statements.

10

GMO Global Equity Allocation Series Fund

(A Series of GMO Series Trust)

Portfolio Management

Day-to-day management of the Fund’s portfolio is the responsibility of the Asset Allocation team at Grantham, Mayo, Van Otterloo & Co. LLC.

Management Discussion and Analysis of Fund Performance

Class R6 shares of GMO Global Equity Allocation Series Fund returned +21.58% (net) for the fiscal year ended February 28, 2017, as compared with +22.07% for the Fund’s benchmark, the MSCI All Country World Index (“ACWI”).

The Fund’s exposure to emerging markets was the largest positive contributor to performance relative to the benchmark and more than offset the negative relative contributions from the underweight to the US and the overweight to Europe. The Fund’s modest cash holdings were a drag on relative performance, given the strong returns generated by equities.

Allocation between sectors proved neutral, as a positive contribution from an underweight position in Healthcare offset a negative contribution from being overweight in Telecommunication Services. Stock selection was beneficial in Utilities, Health Care, and Telecommunication Services, which outweighed negative stock selection from Information Technology and Energy.

Top stock detractors included a lack of exposure to the strongly performing Bank of America, as well as overweight positions in Nippon Telegraph and Telephone Corporation and Valero Energy Corporation. Top stock contributors included overweight positions in Sberbank Russia, Samsung Electronics Co., and Yes Bank Limited (India’s fifth largest private sector bank).

The views expressed herein are exclusively those of Grantham, Mayo, Van Otterloo & Co. LLC as of the date of this report and are subject to change. GMO disclaims any responsibility to update such views. They are not meant as investment advice. References to specific securities are not recommendations of such securities and may not be representative of any GMO portfolio’s current or future investments.

Comparison of Change in Value of a $10,000,000 Investment in

GMO Global Equity Allocation Series Fund Class R6 Shares and the MSCI ACWI +

As of February 28, 2017

Performance data quoted represents past performance and is not indicative of future results. The investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Current performance data may be lower or higher than the performance data provided herein. To obtain performance information up to the most recent month-end, visit www.gmo.com. Performance data shown above for GMO Global Equity Allocation Series Fund (the “Fund”) reflect the performance data of GMO Global Equity Allocation Fund (the “Institutional Fund”) through September 4, 2012 (the commencement date of the Fund), re-stated to reflect the additional fees and expenses of the Fund. Performance data shown above for the Fund is net of all fees after reimbursement from the Manager. Returns would have been lower had certain expenses not been reimbursed during the periods shown and do not include the effect of taxes on distributions and redemptions. All information is unaudited.

The Fund invests substantially all of its assets in shares of the Institutional Fund.

* The MSCI ACWI + represents 75% S&P 500 Index and 25% MSCI ACWI ex-USA prior to May 30, 2008 and MSCI ACWI thereafter.

MSCI data may not be reproduced or used for any other purpose. MSCI provides no warranties, has not prepared or approved this report, and has no liability hereunder.

For S&P disclaimers please visit http://www.gmo.com/America/_Disclaimers/_BenchmarkDisclaimers.htm.

11

GMO Global Equity Allocation Series Fund

(A Series of GMO Series Trust)

Investment Concentration Summary

February 28, 2017 (Unaudited)

Asset Class Summary&	% of Total Net Assets
Common Stocks		96.1	%
Short-Term Investments		1.5
Preferred Stocks		1.3
Investment Funds		0.2
Swap Contracts		0.0	^
Rights/Warrants		0.0	^
Futures Contracts		(0.0	)^
Other		0.9
		100.0	%
Country/Region Summary¤	% of Investments
United States		34.1	%
Japan		11.0
United Kingdom		7.9
Taiwan		6.2
China		4.6
France		4.1
Germany		3.9
Other Emerging		3.9	†
South Korea		3.8
Other Developed		3.4	‡
India		2.9
Switzerland		2.7
Australia		2.7
Hong Kong		2.0
Netherlands		1.6
Spain		1.5
Russia		1.5
Turkey		1.2
Canada		1.0
		100.0	%

& The table above incorporates aggregate indirect asset class exposure resulting from investments in shares of a series of GMO Trust (the “Institutional Fund”) and the series of GMO Trust in which the Institutional Fund invests (collectively referred to as the “underlying funds”), if any. Derivative financial instruments, if any, are based on market values or unrealized appreciation/depreciation rather than notional amounts.

¤ The table above incorporates aggregate indirect country exposure associated with investments in the Institutional Fund and underlying funds, if any. The table excludes short-term investments and includes exposure through the use of derivative financial instruments, if any. The table excludes exposure through forward currency contracts, if any.

† “Other Emerging” is comprised of emerging countries that each represent between (1.0)% and 1.0% of Investments.

‡ “Other Developed” is comprised of developed countries that each represent between (1.0)% and 1.0% of Investments.

^ Rounds to 0.0%.

12

GMO Global Equity Allocation Series Fund

(A Series of GMO Series Trust)

Schedule of Investments

(showing percentage of total net assets)

February 28, 2017

Shares		Description	Value ($)
		MUTUAL FUNDS — 98.8%
		Affiliated Issuers — 98.8%
	645,276	GMO Global Equity Allocation Fund, Class III		14,738,102
		TOTAL MUTUAL FUNDS (Cost $16,252,611)		14,738,102
		TOTAL INVESTMENTS — 98.8% (Cost $16,252,611)		14,738,102
		Other Assets and Liabilities (net) — 1.2%		174,354
		TOTAL NET ASSETS — 100.0%		$14,912,456

See accompanying notes to the financial statements.

13

GMO International Developed Equity Allocation Series Fund

(A Series of GMO Series Trust)

Portfolio Management

Day-to-day management of the Fund’s portfolio is the responsibility of the Asset Allocation team at Grantham, Mayo, Van Otterloo & Co. LLC.

Management Discussion and Analysis of Fund Performance

Class R6 shares of GMO International Developed Equity Allocation Series Fund returned +17.07% (net) for the fiscal year ended February 28, 2017, as compared with +15.75% for the Fund’s benchmark, the MSCI EAFE Index.

The Fund’s exposure to emerging markets was the largest positive contributor to performance relative to the benchmark. The Fund’s modest cash holdings were a drag on relative performance given the strong returns generated by equities.

Allocation between sectors proved neutral, as a positive contribution from an underweight position in Healthcare offset a negative contribution from being overweight in Telecommunication Services. Apart from very modest underperformance in Information Technology, stock selection was beneficial in all sectors with Financials, Health Care, Utilities, and Telecommunication Services of particular note.

Top stock detractors included a lack of exposure to the strongly performing HSBC and overweight positions in Nippon Telegraph and Telephone Corporation and KDDI Corporation (a Japanese telecommunication company). Top stock contributors included overweight positions in Sumitomo Mitsui Financial Group and BASF, as well as a lack of exposure to Novo Nordisk (a Danish pharmaceutical company).

Because some of the securities and instruments held directly or indirectly by the Fund had positive fair value adjustments at the beginning or end of the fiscal year (and the performance of indices are not fair valued), the Fund’s absolute and relative performance is higher than it otherwise would have been in the absence of such fair value adjustments.

The views expressed herein are exclusively those of Grantham, Mayo, Van Otterloo & Co. LLC as of the date of this report and are subject to change. GMO disclaims any responsibility to update such views. They are not meant as investment advice. References to specific securities are not recommendations of such securities and may not be representative of any GMO portfolio’s current or future investments.

Comparison of Change in Value of a $10,000,000 Investment in

GMO International Developed Equity Allocation Series Fund Class R6 Shares and the MSCI EAFE Index

As of February 28, 2017

Performance data quoted represents past performance and is not indicative of future results. The investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Current performance data may be lower or higher than the performance data provided herein. To obtain performance information up to the most recent month-end, visit www.gmo.com. Performance data shown above for GMO International Developed Equity Allocation Series Fund (the “Fund”) reflect the performance data of GMO International Developed Equity Allocation Fund (the “Institutional Fund”) through January 12, 2015 (the commencement date of the Fund), re-stated to reflect the additional fees and expenses of the Fund. Performance data shown above for the Fund is net of all fees after reimbursement from the Manager. Returns would have been lower had certain expenses not been reimbursed during the periods shown and do not include the effect of taxes on distributions and redemptions. All information is unaudited.

The Fund invests substantially all of its assets in shares of the Institutional Fund.

MSCI data may not be reproduced or used for any other purpose. MSCI provides no warranties, has not prepared or approved this report, and has no liability hereunder.

14

GMO International Developed Equity Allocation Series Fund

(A Series of GMO Series Trust)

Investment Concentration Summary

February 28, 2017 (Unaudited)

Asset Class Summary&	% of Total Net Assets
Common Stocks		97.1	%
Preferred Stocks		1.2
Short-Term Investments		1.0
Investment Funds		0.1
Swap Contracts		0.0	^
Rights/Warrants		0.0	^
Futures Contracts		(0.0	)^
Other		0.6
		100.0	%
Country/Region Summary¤	% of Investments
Japan		24.9	%
United Kingdom		15.0
France		8.7
Germany		8.4
Australia		6.0
Switzerland		5.1
Hong Kong		4.3
Spain		3.3
Other Emerging		3.1	†
Other Developed		2.8	‡
Netherlands		2.7
Taiwan		2.6
Canada		2.3
China		2.0
Norway		1.9
Italy		1.8
South Korea		1.6
India		1.2
Israel		1.2
Finland		1.1
		100.0	%

& The table above incorporates aggregate indirect asset class exposure resulting from investments in shares of a series of GMO Trust (the “Institutional Fund”) and the series of GMO Trust in which the Institutional Fund invests (collectively referred to as the “underlying funds”), if any. Derivative financial instruments, if any, are based on market values or unrealized appreciation/depreciation rather than notional amounts.

¤ The table above incorporates aggregate indirect country exposure associated with investments in the Institutional Fund and underlying funds, if any. The table excludes short-term investments and includes exposure through the use of derivative financial instruments, if any. The table excludes exposure through forward currency contracts, if any.

† “Other Emerging” is comprised of emerging countries that each represent between (1.0)% and 1.0% of Investments.

‡ “Other Developed” is comprised of developed countries that each represent between (1.0)% and 1.0% of Investments.

^ Rounds to 0.0%.

15

GMO International Developed Equity Allocation Series Fund

(A Series of GMO Series Trust)

Schedule of Investments

(showing percentage of total net assets)

February 28, 2017

Shares		Description	Value ($)
		MUTUAL FUNDS — 99.4%
		Affiliated Issuers — 99.4%
	706,158	GMO International Developed Equity Allocation Fund, Class III		10,394,649
		TOTAL MUTUAL FUNDS (Cost $10,692,687)		10,394,649
		TOTAL INVESTMENTS — 99.4% (Cost $10,692,687)		10,394,649
		Other Assets and Liabilities (net) — 0.6%		65,552
		TOTAL NET ASSETS — 100.0%		$10,460,201

See accompanying notes to the financial statements.

16

GMO International Equity Allocation Series Fund

(A Series of GMO Series Trust)

Portfolio Management

Day-to-day management of the Fund’s portfolio is the responsibility of the Asset Allocation team at Grantham, Mayo, Van Otterloo & Co. LLC.

Management Discussion and Analysis of Fund Performance

Class R6 shares of GMO International Equity Allocation Series Fund returned +21.25% (net) for the fiscal year ended February 28, 2017, as compared with +19.31% for the MSCI ACWI (All Country World Index) ex USA.

The Fund’s exposure to emerging markets was the largest positive contributor to performance relative to the benchmark. The Fund’s modest cash holdings were a drag on relative performance given the strong returns generated by equities.

Allocation between sectors proved neutral as a positive contribution from an underweight position in Healthcare offset a negative contribution from being overweight in Telecommunication Services. Apart from modest underperformance in Energy and Information Technology, stock selection was beneficial in all sectors with Financials, Utilities, Telecommunication Services, and Health Care of particular note.

Top stock detractors included overweight positions in Nippon Telegraph and Telephone Corporation, KDDI Corporation (a Japanese telecommunication company), and Swiss Re. Top stock contributors included overweight positions in Sberbank Russia and Samsung Electronics Co., as well as a lack of exposure to Novo Nordisk (a Danish pharmaceutical company).

The views expressed herein are exclusively those of Grantham, Mayo, Van Otterloo & Co. LLC as of the date of this report and are subject to change. GMO disclaims any responsibility to update such views. They are not meant as investment advice. References to specific securities are not recommendations of such securities and may not be representative of any GMO portfolio’s current or future investments.

Comparison of Change in Value of a $10,000,000 Investment in

GMO International Equity Allocation Series Fund Class R6 Shares and the MSCI ACWI ex USA

As of February 28, 2017

Performance data quoted represents past performance and is not indicative of future results. The investment return and principal value of an investment will fluctuate so that an investor’s shares, when redeemed, may be worth more or less than their original cost. Current performance data may be lower or higher than the performance data provided herein. To obtain performance information up to the most recent month-end, visit www.gmo.com. Performance data shown above for GMO International Equity Allocation Series Fund (the “Fund”) reflect the performance data of GMO International Equity Allocation Fund (the “Institutional Fund”) through March 30, 2012 (the commencement date of the Fund), re-stated to reflect the additional fees and expenses of the Fund. Performance data shown above for the Fund is net of all fees after reimbursement from the Manager. Returns would have been lower had certain expenses not been reimbursed during the periods shown and do not include the effect of taxes on distributions and redemptions. All information is unaudited.

The Fund invests substantially all of its assets in shares of the Institutional Fund.

MSCI data may not be reproduced or used for any other purpose. MSCI provides no warranties, has not prepared or approved this report, and has no liability hereunder.

17

GMO International Equity Allocation Series Fund

(A Series of GMO Series Trust)

Investment Concentration Summary

February 28, 2017 (Unaudited)

Asset Class Summary&	% of Total Net Assets
Common Stocks		95.8	%
Preferred Stocks		1.9
Short-Term Investments		1.3
Investment Funds		0.2
Swap Contracts		0.0	^
Rights/Warrants		0.0	^
Futures Contracts		(0.0	)^
Other		0.8	^
		100.0	%
Country/Region Summary¤	% of Investments
Japan		18.4	%
United Kingdom		11.2
Taiwan		8.4
China		6.6
France		6.5
Germany		6.3
South Korea		5.4
Australia		4.5
India		4.1
Other Emerging		4.1	†
Switzerland		3.8
Other Developed		3.6	‡
Hong Kong		3.3
Spain		2.5
Russia		2.1
Netherlands		2.0
Canada		1.7
Turkey		1.7
Norway		1.4
Italy		1.3
Brazil		1.1
		100.0	%

& The table above incorporates aggregate indirect asset class exposure resulting from investments in shares of a series of GMO Trust (the “Institutional Fund”) and the series of GMO Trust in which the Institutional Fund invests (collectively referred to as the “underlying funds”), if any. Derivative financial instruments, if any, are based on market values or unrealized appreciation/depreciation rather than notional amounts.

¤ The table above incorporates aggregate indirect country exposure associated with investments in the Institutional Fund and underlying funds. The table excludes short-term investments and includes exposure through the use of derivative financial instruments, if any. The table excludes exposure through forward currency contracts, if any.

† “Other Emerging” is comprised of emerging countries that each represent between (1.0)% and 1.0% of Investments.

‡ “Other Developed” is comprised of developed countries that each represent between (1.0)% and 1.0% of Investments.

^ Rounds to 0.0%.

18

GMO International Equity Allocation Series Fund

(A Series of GMO Series Trust)

Schedule of Investments

(showing percentage of total net assets)

February 28, 2017

Shares		Description	Value ($)
		MUTUAL FUNDS — 99.1%
		Affiliated Issuers — 99.1%
	8,105,413	GMO International Equity Allocation Fund, Class III		222,817,799
		TOTAL MUTUAL FUNDS (Cost $236,239,318)		222,817,799
		TOTAL INVESTMENTS — 99.1% (Cost $236,239,318)		222,817,799
		Other Assets and Liabilities (net) — 0.9%		2,052,396
		TOTAL NET ASSETS — 100.0%		$224,870,195

See accompanying notes to the financial statements.

19

GMO Series Trust

Statements of Assets and Liabilities — February 28, 2017

	Benchmark- Free Allocation Series Fund				Emerging Countries Series Fund				Global Asset Allocation Series Fund				Global Equity Allocation Series Fund				International Developed Equity Allocation Series Fund				International Equity Allocation Series Fund
Assets:
Investments in affiliated issuers, at value (Notes 2 and 10)(a)		$	293,074,743			$	12,626,796			$	178,150,315			$	14,738,102			$	10,394,649			$	222,817,799
Cash			2,509,465				145,038				2,222,450				174,200				70,131				2,078,467
Receivable for Fund shares sold			79,777,372				—				79,571				3,356				98				6,946
Receivable for reimbursement by GMO (Note 5)			—				652				—				140				224				280
Total assets			375,361,580				12,772,486				180,452,336				14,915,798				10,465,102				224,903,492
Liabilities:
Payable for investments purchased			77,458,603				—				—				—				—				—
Payable for Fund shares repurchased			254,580				11,675				96,889				26				100				19,146
Payable to affiliate for (Note 5):
Administration fee			8,346				890				6,873				572				402				8,651
Accrued expenses			20,239				4,962				8,757				2,744				4,399				5,500
Total liabilities			77,741,768				17,527				112,519				3,342				4,901				33,297
Net assets		$	297,619,812			$	12,754,959			$	180,339,817			$	14,912,456			$	10,460,201			$	224,870,195
Net assets consist of:
Paid-in capital		$	311,025,209			$	13,690,739			$	218,847,743			$	17,373,217			$	10,777,415			$	245,928,778
Accumulated undistributed net investment income			9,030				448				40,607				7,554				3,939				41,830
Accumulated net realized loss			(7,459,354	)			(647,003	)			(20,375,593	)			(953,806	)			(23,115	)			(7,678,894	)
Net unrealized depreciation			(5,955,073	)			(289,225	)			(18,172,940	)			(1,514,509	)			(298,038	)			(13,421,519	)
		$	297,619,812			$	12,754,959			$	180,339,817			$	14,912,456			$	10,460,201			$	224,870,195
Net assets attributable to:
Class R6		$	297,619,812			$	12,754,959			$	180,339,817			$	14,912,456			$	10,460,201			$	224,870,195
Shares outstanding:
Class R6			29,896,184				1,335,081				20,155,165				1,532,904				1,095,694				24,989,188
Net asset value per share:
Class R6		$	9.96			$	9.55			$	8.95			$	9.73			$	9.55			$	9.00
(a)    Cost of investments — affiliated issuers:		$	299,029,816			$	12,916,021			$	196,323,255			$	16,252,611			$	10,692,687			$	236,239,318

See accompanying notes to the financial statements.

20

GMO Series Trust

Statements of Operations — Year Ended February 28, 2017

	Benchmark- Free Allocation Series Fund				Emerging Countries Series Fund				Global Asset Allocation Series Fund
Investment Income:
Dividends from affiliated issuers (Note 10)		$	3,424,085			$	146,755			$	4,623,951
Interest			267				—				315
Total investment income			3,424,352				146,755				4,624,266
Expenses:
Administration fee — (Note 5)			113,233				5,442				120,858
Registration fees			28,918				6,285				19,320
Total expenses			142,151				11,727				140,178
Fees and expenses reimbursed by GMO (Note 5)			(28,918	)			(6,285	)			(19,320	)
Net expenses			113,233				5,442				120,858
Net investment income (loss)			3,311,119				141,313				4,503,408
Realized and unrealized gain (loss):
Net realized gain (loss) on:
Investments in affiliated issuers			(6,434,598	)			(260,010	)			(17,791,431	)
Net realized gain (loss)			(6,434,598	)			(260,010	)			(17,791,431	)
Change in net unrealized appreciation (depreciation) on:
Investments in affiliated issuers			28,607,118				3,292,490				44,187,614
Net change in unrealized appreciation (depreciation)			28,607,118				3,292,490				44,187,614
Net realized and unrealized gain (loss)			22,172,520				3,032,480				26,396,183
Net increase (decrease) in net assets resulting from operations		$	25,483,639			$	3,173,793			$	30,899,591

See accompanying notes to the financial statements.

21

GMO Series Trust

Statements of Operations — Year Ended February 28, 2017 — (Continued)

	Global Equity Allocation Series Fund				International Developed Equity Allocation Series Fund				International Equity Allocation Series Fund
Investment Income:
Dividends from affiliated issuers (Note 10)		$	446,104			$	384,204			$	7,244,066
Interest			18				—				288
Total investment income			446,122				384,204				7,244,354
Expenses:
Administration fee (Note 5)			7,066				4,815				112,223
12b-1 fee — Class R5 (Note 5)			—				—				3,421	*
Registration fees			4,825				8,920				9,650
Total expenses			11,891				13,735				125,294
Fees and expenses reimbursed by GMO (Note 5)			(4,825	)			(8,920	)			(9,650	)
Net expenses			7,066				4,815				115,644
Net investment income (loss)			439,056				379,389				7,128,710
Realized and unrealized gain (loss):
Net realized gain (loss) on:
Investments in affiliated issuers			(650,074	)			(16,577	)			(7,172,413	)
Realized gain distributions from affiliated issuers (Note 10)			262,437				—				—
Net realized gain (loss)			(387,637	)			(16,577	)			(7,172,413	)
Change in net unrealized appreciation (depreciation) on:
Investments in affiliated issuers			2,696,438				1,129,261				44,031,314
Net change in unrealized appreciation (depreciation)			2,696,438				1,129,261				44,031,314
Net realized and unrealized gain (loss)			2,308,801				1,112,684				36,858,901
Net increase (decrease) in net assets resulting from operations		$	2,747,857			$	1,492,073			$	43,987,611

* Class R5 liquidated on May 20, 2016.

See accompanying notes to the financial statements.

22

GMO Series Trust

Statements of Changes in Net Assets

	Benchmark-Free Allocation Series Fund								Emerging Countries Series Fund
	Year Ended February 28/29,								Year Ended February 28/29,
	2017				2016				2017				2016
Increase (decrease) in net assets:
Operations:
Net investment income (loss)		$	3,311,119			$	3,596,092			$	141,313			$	273,323
Net realized gain (loss)			(6,434,598	)			2,655,153				(260,010	)			(295,053	)
Change in net unrealized appreciation (depreciation)			28,607,118				(40,547,732	)			3,292,490				(2,953,407	)
Net increase (decrease) in net assets from operations			25,483,639				(34,296,487	)			3,173,793				(2,975,137	)
Distributions to shareholders from:
Net investment income
Class R6			(3,280,214	)			(4,023,611	)			(140,103	)			(273,280	)
Net realized gains
Class R6			—				(5,674,620	)			—				—
Return of capital
Class R6			—				—				—				(13,299	)
Net share transactions (Note 9):
Class R6			7,493,454				30,808,107				547,432				(1,359,313	)
Increase (decrease) in net assets resulting from net share transactions			7,493,454				30,808,107				547,432				(1,359,313	)
Total increase (decrease) in net assets			29,696,879				(13,186,611	)			3,581,122				(4,621,029	)
Net assets:
Beginning of period			267,922,933				281,109,544				9,173,837				13,794,866
End of period		$	297,619,812			$	267,922,933			$	12,754,959			$	9,173,837
Accumulated undistributed net investment income		$	9,030			$	—			$	448			$	—
Distributions in excess of net investment income		$	—			$	(21,875	)		$	—			$	(762	)

See accompanying notes to the financial statements.

23

GMO Series Trust

Statements of Changes in Net Assets — (Continued)

	Global Asset Allocation Series Fund								Global Equity Allocation Series Fund
	Year Ended February 28/29,								Year Ended February 28/29,
	2017				2016				2017				2016
Increase (decrease) in net assets:
Operations:
Net investment income (loss)		$	4,503,408			$	11,548,653			$	439,056			$	384,551
Net realized gain (loss)			(17,791,431	)			30,828,023				(387,637	)			583,532
Change in net unrealized appreciation (depreciation)			44,187,614				(85,504,307	)			2,696,438				(3,610,444	)
Net increase (decrease) in net assets from operations			30,899,591				(43,127,631	)			2,747,857				(2,642,361	)
Distributions to shareholders from:
Net investment income
Class R6			(4,759,069	)			(11,683,073	)			(435,329	)			(383,520	)
Net realized gains
Class R6			—				(47,114,249	)			(233,246	)			(1,042,868	)
Net share transactions (Note 9):
Class R6			(135,518,235	)			(424,331,521	)			(140,500	)			250,021
Increase (decrease) in net assets resulting from net share transactions			(135,518,235	)			(424,331,521	)			(140,500	)			250,021
Total increase (decrease) in net assets			(109,377,713	)			(526,256,474	)			1,938,782				(3,818,728	)
Net assets:
Beginning of period			289,717,530				815,974,004				12,973,674				16,792,402
End of period		$	180,339,817			$	289,717,530			$	14,912,456			$	12,973,674
Accumulated undistributed net investment income		$	40,607			$	296,268			$	7,554			$	3,876

See accompanying notes to the financial statements.

24

GMO Series Trust

Statements of Changes in Net Assets — (Continued)

	International Developed Equity Allocation Series Fund								International Equity Allocation Series Fund
	Year Ended February 28/29,								Year Ended February 28/29,
	2017				2016				2017				2016
Increase (decrease) in net assets:
Operations:
Net investment income (loss)		$	379,389			$	292,948			$	7,128,710			$	7,611,600
Net realized gain (loss)			(16,577	)			45,605				(7,172,413	)			9,897,712
Change in net unrealized appreciation (depreciation)			1,129,261				(2,373,979	)			44,031,314				(73,508,121	)
Net increase (decrease) in net assets from operations			1,492,073				(2,035,426	)			43,987,611				(55,998,809	)
Distributions to shareholders from:
Net investment income
Class R5			—				—				—	*			(507,233	)
Class R6			(377,438	)			(290,923	)			(7,271,019	)			(7,076,063	)
Total distributions from net investment income			(377,438	)			(290,923	)			(7,271,019	)			(7,583,296	)
Net realized gains
Class R5			—				—				—	*			(831,911	)
Class R6			—				(60,556	)			—				(11,037,606	)
Total distributions from net realized gains			—				(60,556	)			—				(11,869,517	)
Net share transactions (Note 9):
Class R5			—				—				(15,691,732	)*			(1,161,713	)
Class R6			729,516				392,568				(23,036,147	)			25,420,473
Increase (decrease) in net assets resulting from net share transactions			729,516				392,568				(38,727,879	)			24,258,760
Total increase (decrease) in net assets			1,844,151				(1,994,337	)			(2,011,287	)			(51,192,862	)
Net assets:
Beginning of period			8,616,050				10,610,387				226,881,482				278,074,344
End of period		$	10,460,201			$	8,616,050			$	224,870,195			$	226,881,482
Accumulated undistributed net investment income		$	3,939			$	1,988			$	41,830			$	184,139

* Class R5 liquidated on May 20, 2016.

See accompanying notes to the financial statements.

25

GMO Series Trust

Financial Highlights

(For a share outstanding throughout each period)

BENCHMARK-FREE ALLOCATION SERIES FUND

	Class R6 Shares
	Year Ended February 28/29,								Period from May 1, 2014 through February 28, 2015(a)				Year Ended April 30, 2014				Period from January 24, 2013 (commencement of operations) through April 30, 2013
	2017				2016
Net asset value, beginning of period		$	9.08			$	10.61			$	10.84			$	10.35			$	10.00
Income (loss) from investment operations:
Net investment income (loss)(b)†			0.14				0.12				0.23				0.15				(0.00	)(c)
Net realized and unrealized gain (loss)			0.89				(1.31	)			0.03				0.58				0.35
Total from investment operations			1.03				(1.19	)			0.26				0.73				0.35
Less distributions to shareholders:
From net investment income			(0.15	)			(0.14	)			(0.32	)			(0.23	)			—
From net realized gains			—				(0.20	)			(0.17	)			(0.01	)			—
Total distributions			(0.15	)			(0.34	)			(0.49	)			(0.24	)			—
Net asset value, end of period		$	9.96			$	9.08			$	10.61			$	10.84			$	10.35
Total Return(d)			11.41	%			(11.48	)%			2.47	%**			7.15	%			3.50	%**
Ratios/Supplemental Data:
Net assets, end of period (000’s)		$	297,620			$	267,923			$	281,110			$	164,442			$	160,138
Net expenses to average daily net assets(e)			0.05	%			0.05	%			0.05	%*			0.05	%			0.05	%*
Net investment income (loss) to average daily net assets(b)			1.46	%			1.26	%			2.53	%*			1.41	%			(0.05	)%*
Portfolio turnover rate			34	%			27	%			6	%**			8	%			0	%**
Fees and expenses reimbursed and/or waived by GMO to average daily net assets:			0.01	%			0.01	%			0.02	%*			0.00	%(f)			0.01	%*

(a) On September 18, 2014, the Trustees approved a change in the fiscal year end of the Fund from April 30 to February 28/29 which resulted in a ten month period.

(b) Net investment income is affected by the timing of the declaration of dividends by the Institutional Fund in which the Fund invests.

(c) Rounds to less than $0.01.

(d) The total returns would have been lower had certain expenses not been reimbursed during the periods shown and assumes the effect of reinvested distributions, if any.

(e) Net expenses exclude expenses incurred indirectly through investment in the Institutional Fund and Underlying Funds, if any (Note 5).

(f) Fees and expenses reimbursed and/or waived by GMO to average daily net assets were less than 0.01%.

† Calculated using average shares outstanding throughout the period.

* Annualized.

** Not annualized.

See accompanying notes to the financial statements.

26

GMO Series Trust

Financial Highlights

(For a share outstanding throughout each period)

EMERGING COUNTRIES SERIES FUND

	Class R6 Shares
	Year Ended February 28/29,								Period from May 2, 2014 (commencement of operations) through February 28, 2015
	2017				2016
Net asset value, beginning of period		$	7.13			$	9.51			$	10.00
Income (loss) from investment operations:
Net investment income (loss)(a)†			0.11				0.20				0.35
Net realized and unrealized gain (loss)			2.42				(2.36	)			(0.47	)
Total from investment operations			2.53				(2.16	)			(0.12	)
Less distributions to shareholders:
From net investment income			(0.11	)			(0.21	)			(0.35	)
From net realized gains			—				—				(0.02	)
Return of capital			—				(0.01	)			—
Total distributions			(0.11	)			(0.22	)			(0.37	)
Net asset value, end of period		$	9.55			$	7.13			$	9.51
Total Return(b)			35.61	%			(22.92	)%			(1.01	)%**
Ratios/Supplemental Data:
Net assets, end of period (000’s)		$	12,755			$	9,174			$	13,795
Net expenses to average daily net assets(c)			0.05	%			0.05	%			0.05	%*
Net investment income (loss) to average daily net assets(a)			1.30	%			2.36	%			4.17	%*
Portfolio turnover rate			11	%			9	%			17	%**
Fees and expenses reimbursed and/or waived by GMO to average daily net assets:			0.06	%			0.03	%			0.01	%*

(a) Net investment income is affected by the timing of the declaration of dividends by the Institutional Fund in which the Fund invests.

(b) The total returns would have been lower had certain expenses not been reimbursed during the periods shown and assumes the effect of reinvested distributions, if any.

(c) Net expenses exclude expenses incurred indirectly through investment in the Institutional Fund and Underlying Funds, if any (Note 5).

† Calculated using average shares outstanding throughout the period.

* Annualized.

** Not annualized.

See accompanying notes to the financial statements.

27

GMO Series Trust

Financial Highlights

(For a share outstanding throughout each period)

GLOBAL ASSET ALLOCATION SERIES FUND

	Class R6 Shares
	Year Ended February 28/29,								Period from May 1, 2014 through February 28, 2015(a)				Year Ended April 30, 2014				Period from July 31, 2012 (commencement of operations) through April 30, 2013
	2017				2016
Net asset value, beginning of period		$	8.13			$	10.90			$	11.52			$	10.84			$	10.00
Income (loss) from investment operations:
Net investment income (loss)(b)†			0.16				0.28				0.41				0.27				0.32
Net realized and unrealized gain (loss)			0.88				(1.40	)			(0.17	)			0.69				0.79
Total from investment operations			1.04				(1.12	)			0.24				0.96				1.11
Less distributions to shareholders:
From net investment income			(0.22	)			(0.37	)			(0.42	)			(0.26	)			(0.27	)
From net realized gains			—				(1.28	)			(0.44	)			(0.02	)			(0.00	)(c)
Total distributions			(0.22	)			(1.65	)			(0.86	)			(0.28	)			(0.27	)
Net asset value, end of period		$	8.95			$	8.13			$	10.90			$	11.52			$	10.84
Total Return(d)			12.87	%			(10.95	)%			2.31	%**			9.02	%			11.36	%**
Ratios/Supplemental Data:
Net assets, end of period (000’s)		$	180,340			$	289,718			$	815,974			$	802,733			$	592,415
Net expenses to average daily net assets(e)			0.05	%			0.05	%			0.05	%*			0.05	%			0.05	%*
Net investment income (loss) to average daily net assets(b)			1.86	%			2.76	%			4.33	%*			2.46	%			4.07	%*
Portfolio turnover rate			2	%			7	%			6	%**			2	%			6	%**
Fees and expenses reimbursed and/or waived by GMO to average daily net assets:			0.01	%			0.01	%			0.00	%*(f)			0.00	%(f)			0.00	%*(f)

(a) On September 18, 2014, the Trustees approved a change in the fiscal year end of the Fund from April 30 to February 28/29 which resulted in a ten month period.

(b) Net investment income is affected by the timing of the declaration of dividends by the Institutional Fund in which the Fund invests.

(c) Rounds to less than $0.01.

(d) The total returns would have been lower had certain expenses not been reimbursed during the periods shown and assumes the effect of reinvested distributions, if any.

(e) Net expenses exclude expenses incurred indirectly through investment in the Institutional Fund and Underlying Funds, if any (Note 5).

(f) Fees and expenses reimbursed and/or waived by GMO to average daily net assets were less than 0.01%.

† Calculated using average shares outstanding throughout the period.

* Annualized.

** Not annualized.

See accompanying notes to the financial statements.

28

GMO Series Trust

Financial Highlights

(For a share outstanding throughout each period)

GLOBAL EQUITY ALLOCATION SERIES FUND

	Class R6 Shares
	Year Ended February 28/29,								Period from May 1, 2014 through February 28, 2015(a)				Year Ended April 30, 2014				Period from September 4, 2012 (commencement of operations) through April 30, 2013
	2017				2016
Net asset value, beginning of period		$	8.39			$	11.05			$	12.02			$	11.14			$	10.00
Income (loss) from investment operations:
Net investment income (loss)(b)†			0.29				0.25				0.53				0.45				0.26
Net realized and unrealized gain (loss)			1.49				(1.93	)			(0.52	)			1.14				1.23
Total from investment operations			1.78				(1.68	)			0.01				1.59				1.49
Less distributions to shareholders:
From net investment income			(0.29	)			(0.27	)			(0.38	)			(0.49	)			(0.35	)
From net realized gains			(0.15	)			(0.71	)			(0.60	)			(0.22	)			—
Total distributions			(0.44	)			(0.98	)			(0.98	)			(0.71	)			(0.35	)
Net asset value, end of period		$	9.73			$	8.39			$	11.05			$	12.02			$	11.14
Total Return(c)			21.58	%			(16.02	)%			0.28	%**			14.70	%			15.29	%**
Ratios/Supplemental Data:
Net assets, end of period (000’s)		$	14,912			$	12,974			$	16,792			$	6,335			$	1,461
Net expenses to average daily net assets(d)			0.05	%			0.05	%			0.05	%*			0.05	%			0.05	%*
Net investment income (loss) to average daily net assets(b)			3.11	%			2.51	%			5.55	%*			3.94	%			3.76	%*
Portfolio turnover rate			14	%			18	%			23	%**			28	%			46	%**
Fees and expenses reimbursed and/or waived by GMO to average daily net assets:			0.03	%			0.02	%			0.02	%*			0.03	%			0.58	%*

(a) On September 18, 2014, the Trustees approved a change in the fiscal year end of the Fund from April 30 to February 28/29 which resulted in a ten month period.

(b) Net investment income is affected by the timing of the declaration of dividends by the Institutional Fund in which the Fund invests.

(c) The total returns would have been lower had certain expenses not been reimbursed during the periods shown and assumes the effect of reinvested distributions, if any.

(d) Net expenses exclude expenses incurred indirectly through investment in the Institutional Fund and Underlying Funds, if any (Note 5).

† Calculated using average shares outstanding throughout the period.

* Annualized.

** Not annualized.

See accompanying notes to the financial statements.

29

GMO Series Trust

Financial Highlights

(For a share outstanding throughout each period)

INTERNATIONAL DEVELOPED EQUITY ALLOCATION SERIES FUND

	Class R6 Shares
	Year Ended February 28/29,								Period from January 12, 2015 (commencement of operations) through February 28, 2015
	2017				2016
Net asset value, beginning of period		$	8.48			$	11.00			$	10.00
Income (loss) from investment operations:
Net investment income (loss)(a)†			0.37				0.31				0.00	(b)
Net realized and unrealized gain (loss)			1.06				(2.47	)			1.00
Total from investment operations			1.43				(2.16	)			1.00
Less distributions to shareholders:
From net investment income			(0.36	)			(0.30	)			—
From net realized gains			—				(0.06	)			—
Total distributions			(0.36	)			(0.36	)			—
Net asset value, end of period		$	9.55			$	8.48			$	11.00
Total Return(c)			17.07	%			(19.90	)%			10.00	%**
Ratios/Supplemental Data:
Net assets, end of period (000’s)		$	10,460			$	8,616			$	10,610
Net expenses to average daily net assets(d)			0.05	%			0.05	%			0.05	%*
Net investment income (loss) to average daily net assets(a)			3.94	%			3.04	%			(0.05	)%*
Portfolio turnover rate			3	%			7	%			2	%**
Fees and expenses reimbursed and/or waived by GMO to average daily net assets:			0.09	%			0.07	%			0.05	%*

(a) Net investment income is affected by the timing of the declaration of dividends by the Institutional Fund in which the Fund invests.

(b) Rounds to less than $0.01.

(c) The total returns would have been lower had certain expenses not been reimbursed during the periods shown and assumes the effect of reinvested distributions, if any.

(d) Net expenses exclude expenses incurred indirectly through investment in the Institutional Fund and Underlying Funds, if any (Note 5).

† Calculated using average shares outstanding throughout the period.

* Annualized.

** Not annualized.

See accompanying notes to the financial statements.

30

GMO Series Trust

Financial Highlights

(For a share outstanding throughout each period)

INTERNATIONAL EQUITY ALLOCATION SERIES FUND

	Class R6 Shares
	Year Ended February 28/29,								Period from May 1, 2014 through February 28, 2015(a)				Year Ended April 30,
	2017				2016								2014				2013
Net asset value, beginning of period		$	7.68			$	10.51			$	12.10			$	10.97			$	9.77
Income (loss) from investment operations:
Net investment income (loss)(b)†			0.28				0.29				0.45				0.33				0.33
Net realized and unrealized gain (loss)			1.33				(2.37	)			(1.00	)			1.19				1.18
Total from investment operations			1.61				(2.08	)			(0.55	)			1.52				1.51
Less distributions to shareholders:
From net investment income			(0.29	)			(0.29	)			(0.44	)			(0.34	)			(0.31	)
From net realized gains			—				(0.46	)			(0.60	)			(0.05	)			—
Total distributions			(0.29	)			(0.75	)			(1.04	)			(0.39	)			(0.31	)
Net asset value, end of period		$	9.00			$	7.68			$	10.51			$	12.10			$	10.97
Total Return(c)			21.25	%			(20.53	)%			(4.45	)%**			14.04	%			15.77	%
Ratios/Supplemental Data:
Net assets, end of period (000’s)		$	224,870			$	212,327			$	256,975			$	307,375			$	280,869
Net expenses to average daily net assets(d)			0.05	%			0.05	%			0.05	%*			0.05	%			0.05	%
Net investment income (loss) to average daily net assets(b)			3.23	%			3.05	%			4.85	%*			2.92	%			3.26	%
Portfolio turnover rate			3	%			4	%			8	%**			6	%			3	%
Fees and expenses reimbursed and/or waived by GMO to average daily net assets:(e)			0.00	%			0.00	%			0.00	%*			0.00	%			0.00	%

(a) On September 18, 2014, the Trustees approved a change in the fiscal year end of the Fund from April 30 to February 28/29 which resulted in a ten month period.

(b) Net investment income is affected by the timing of the declaration of dividends by the Institutional Fund in which the Fund invests.

(c) The total returns would have been lower had certain expenses not been reimbursed during the periods shown and assumes the effect of reinvested distributions, if any.

(d) Net expenses exclude expenses incurred indirectly through investment in the Institutional Fund and Underlying Funds, if any (Note 5).

(e) Fees and expenses reimbursed and/or waived by GMO to average daily net assets were less than 0.01%.

† Calculated using average shares outstanding throughout the period.

* Annualized.

** Not annualized.

See accompanying notes to the financial statements.

31

GMO Series Trust

Notes to Financial Statements

February 28, 2017

1. Organization

Each of Benchmark-Free Allocation Series Fund, Emerging Countries Series Fund, Global Asset Allocation Series Fund, Global Equity Allocation Series Fund, International Developed Equity Allocation Series Fund and International Equity Allocation Series Fund (each a “Fund” and collectively the “Funds”) is a series of GMO Series Trust (the “Trust”). The Trust is registered under the Investment Company Act of 1940, as amended (the “1940 Act”), as an open-end management investment company. The Trust was established as a Massachusetts business trust under the laws of The Commonwealth of Massachusetts on May 27, 2011. The Declaration of Trust of the Trust permits the Trustees of the Trust (“Trustees”) to create an unlimited number of series of shares (Funds) and to subdivide Funds into classes. The Funds are diversified as that term is defined in the 1940 Act. The Funds are advised and managed by Grantham, Mayo, Van Otterloo & Co. LLC (“GMO”).

On September 18, 2014, the Trustees approved a change in the fiscal year end of the Funds from April 30 to February 28/29. Accordingly, the Funds’ financial statements and related notes include information for the ten month period ended February 28, 2015 and the one year period ended April 30 of prior years, if applicable.

Each Fund invests substantially all of its assets in shares of another fund that is a series of GMO Trust and is managed by GMO (each an “Institutional Fund”). The performance and operations of each Fund are directly affected by the performance and operations of the relevant Institutional Fund. Each Institutional Fund, except GMO Emerging Countries Fund, is a fund of funds that invests primarily in shares of other GMO Funds (“underlying funds”). Information about the Institutional Funds for their year ended February 28, 2017 is contained in the Institutional Funds’ financial statements of the same date. Additional selected information about the Institutional Funds and underlying funds as of the date of this report can be found in Note 11, “Institutional Fund information.” The Funds’ financial statements should be read in conjunction with the financial statements of the Institutional Funds and underlying funds, which can be obtained from the Securities and Exchange Commission’s (“SEC”) EDGAR database on its website at www.sec.gov or by calling (617) 346-7646 (collect) or visiting www.gmo.com.

The following table provides information about each Fund’s benchmark (if any), investment objective and the portion of the corresponding Institutional Fund owned by the Fund as of February 28, 2017:

Fund Name	Benchmark	Investment Objective	Percent of Institutional Fund Owned
Benchmark-Free Allocation Series Fund	Not Applicable	Positive total return not “relative” return		2.1%
Emerging Countries Series Fund	S&P/IFCI Composite Index	Total return in excess of benchmark		45.6%
Global Asset Allocation Series Fund	GMO Global Asset Allocation Index (65% MSCI ACWI and 35% Barclays U.S. Aggregate Index)	Total return greater than benchmark		7.3%
Global Equity Allocation Series Fund	MSCI ACWI	Total return greater than benchmark		0.7%
International Developed Equity Allocation Series Fund	MSCI EAFE Index	Total return greater than benchmark		1.7%
International Equity Allocation Series Fund	MSCI ACWI ex USA	Total return greater than benchmark		20.5%

2. Significant accounting policies

The following is a summary of significant accounting policies followed by each Fund in the preparation of its financial statements. These policies are in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and have been consistently followed by the Funds in preparing these financial statements. The preparation of financial statements in accordance with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts and

32

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

disclosures in the financial statements. Actual results could differ from those estimates. The accounting records of the Funds are maintained in U.S. dollars.

Portfolio valuation

Investments in shares of the Institutional Funds are valued at their most recent net asset value. See Note 11 for details on Institutional Fund valuation policies.

U.S. GAAP requires the Funds to disclose the fair value of their investments in a three-level hierarchy (Levels 1, 2 and 3). The valuation hierarchy is based upon the relative observability of inputs to the valuation of the Funds’ investments. The inputs or methodologies used for valuing securities are not necessarily an indication of the risk associated with investing in those securities.

Changes in valuation techniques may result in transfers into or out of an investment’s assigned level within the fair value hierarchy. In addition, in periods of market dislocation, the observability of prices and inputs may be reduced for many instruments. This condition, as well as changes related to the liquidity of investments, could cause a security to be reclassified between levels.

U.S. GAAP requires additional disclosures about fair value measurements for material Level 3 securities and derivatives, if any (determined by each category of asset or liability as compared to a Fund’s total net assets). At February 28, 2017, there were no direct material Level 3 classes of investments or derivatives with significant unobservable inputs subject to this additional disclosure.

The three levels are defined as follows:

Level 1 – Valuations based on quoted prices for identical securities in active markets.

Level 2 – Valuations determined using other significant direct or indirect observable inputs.

Level 3 – Valuations based primarily on inputs that are unobservable and significant.

Each Fund classified its investments as Level 1 as of February 28, 2017. For the summary of valuation inputs of the Institutional Funds and the series of GMO Trust in which the Institutional Funds and underlying funds invest, if any, please refer to their most recent financial statements and/or for the net aggregate indirect exposure to these valuation methodologies as of the date of this report, see Note 11. The Institutional Funds and underlying funds have a February 28/29 fiscal year end.

The Funds had no transfers between levels of the fair value hierarchy during the year ended February 28, 2017.

Cash

Cash, if any, on the Statements of Assets and Liabilities consists of cash balances held with the custodian.

Taxes and distributions

Each Fund has elected to be treated and intends to qualify each tax year as a regulated investment company under Subchapter M of the Internal Revenue Code of 1986, as amended (the “Code”). Each Fund intends to distribute its net investment income, if any, and its net realized short-term and long-term capital gains, if any, after giving effect to any available capital loss carryforwards for U.S. federal income tax purposes. Therefore, each Fund makes no provision for U.S. federal income or excise taxes.

The policy of each Fund is to declare and pay dividends of its net investment income, if any, at least annually, although the Funds are permitted to, and will from time to time declare and pay dividends of net investment income, if any, more frequently. Each Fund also intends to distribute net realized short-term and long-term capital gains, if any, at least annually. In addition, each Fund may, from time to time at their discretion, make unscheduled distributions in advance of large redemptions by shareholders or as otherwise deemed appropriate by a Fund. Typically all distributions are reinvested in additional shares of each Fund, at net asset value, unless GMO or its agents receive and process a shareholder election to receive cash distributions. Distributions to shareholders are recorded by each Fund on the ex-dividend date.

Certain Institutional Funds have previously filed for and/or may file for additional tax refunds with respect to certain taxes withheld by certain countries. Generally, the amount of such refunds that an Institutional Fund reasonably determines are collectible and free from significant contingencies are reflected in an Institutional Fund’s net asset value. In certain circumstances, an Institutional

33

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

Fund’s receipt of such refunds may cause the Institutional Fund and/or its shareholders to be liable for U.S. federal income taxes and interest charges.

Foreign taxes paid by the Institutional Funds may be treated, to the extent permissible under the Code (and other applicable U.S. federal tax guidance) and if that Fund so elects, as if paid by U.S. shareholders of that Fund.

Income and capital gain distributions are determined in accordance with U.S. federal income tax regulations, which may differ from U.S. GAAP. Certain capital accounts in the financial statements are periodically adjusted for permanent differences in order to reflect their tax character. These adjustments have no impact on net assets or net asset value per share. Temporary differences that arise from recognizing certain items of income, expense, gain or loss in different periods for financial statement and tax purposes will likely reverse at some time in the future. Distributions in excess of net investment income or net realized gains are temporary over-distributions for financial statement purposes resulting from differences in the recognition or classification of income or distributions for financial statement and tax purposes.

U.S. GAAP and tax accounting differences for each Fund primarily relate to reasons described in the following table:

Differences related to:

Benchmark-Free Allocation Series  Fund

Emerging Countries Series Fund

Global Asset Allocation Series Fund

Global Equity Allocation Series Fund

International Developed Equity Allocation Series Fund

International Equity Allocation Series Fund

Capital loss carry forwards

X

X

X

X

Losses on wash sale transactions

X

X

X

X

X

X

Post-October capital losses

X

X

X

X

X

The tax character of distributions declared by each Fund to shareholders is as follows:

	Tax year ended February 28, 2017						Tax year ended February 29, 2016
Fund Name	Ordinary Income (including any net short-term capital gain) ($)		Net Long-Term Capital Gain ($)		Total Distributions ($)		Ordinary Income (including any net short-term capital gain) ($)		Net Long-Term Capital Gain ($)		Return of Capital ($)		Total Distributions ($)
Benchmark-Free Allocation Series Fund		3,280,214		—		3,280,214		3,937,592		5,760,639		—		9,698,231
Emerging Countries Series Fund		140,103		—		140,103		273,280		—		13,299		286,579
Global Asset Allocation Series Fund		4,759,069		—		4,759,069		11,685,616		47,111,706		—		58,797,322
Global Equity Allocation Series Fund		435,378		233,197		668,575		383,520		1,042,868		—		1,426,388
International Developed Equity Allocation Series Fund		377,438		—		377,438		351,479		—		—		351,479
International Equity Allocation Series Fund		7,271,019		—		7,271,019		7,585,111		11,867,702		—		19,452,813

Distributions in excess of a Fund’s tax basis earnings and profits, if significant, are reported in the Funds’ financial statements as a return of capital.

34

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

As of February 28, 2017, the components of distributable earnings on a tax basis and certain tax attributes for the Funds consisted of the following:

Fund Name	Undistributed Ordinary Income (including any net short-term capital gain) ($)		Late-Year Ordinary Loss Deferral ($)		Capital Loss Carryforwards ($)		Post-October Capital Losses ($)
Benchmark-Free Allocation Series Fund		26,377		(17,347)		(5,051,296)		(627,673)
Emerging Countries Series Fund		1,445		(997)		(375,157)		—
Global Asset Allocation Series Fund		54,904		(14,297)		(12,342,820)		(6,302,206)
Global Equity Allocation Series Fund		8,741		(1,187)		—		(25,381)
International Developed Equity Allocation Series Fund		4,774		(835)		(3,767)		—
International Equity Allocation Series Fund		59,714		(17,884)		(6,372,140)		(362,663)

As of February 28, 2017, certain Funds had capital loss carryforwards available to offset future realized gains, if any, to the extent permitted by the Code. Utilization of the capital loss carryforwards, post-October capital losses, late-year ordinary losses and losses realized subsequent to February 28, 2017, if any, could be subject to further limitations imposed by the Code related to share ownership activity. The Funds’ capital loss carryforwards are as follows:

Fund Name	Short-Term ($)		Long-Term ($)
	No Expiration Date		No Expiration Date
Benchmark-Free Allocation Series Fund		—		(5,051,296)
Emerging Countries Series Fund		(61,260)		(313,897)
Global Asset Allocation Series Fund		—		(12,342,820)
Global Equity Allocation Series Fund		—		—
International Developed Equity Allocation Series Fund		—		(3,767)
International Equity Allocation Series Fund		—		(6,372,140)

As of February 28, 2017, the approximate cost for U.S. federal income tax purposes and the aggregate investment-level gross and net unrealized appreciation (depreciation) in the value of investments were as follows:

Fund Name	Aggregate Cost ($)		Gross Unrealized Appreciation ($)		Gross Unrealized (Depreciation) ($)		Net Unrealized Appreciation (Depreciation) ($)
Benchmark-Free Allocation Series Fund		300,810,201		—		(7,735,458)		(7,735,458)
Emerging Countries Series Fund		13,187,865		—		(561,069)		(561,069)
Global Asset Allocation Series Fund		198,053,822		—		(19,903,507)		(19,903,507)
Global Equity Allocation Series Fund		17,181,036		—		(2,442,934)		(2,442,934)
International Developed Equity Allocation Series Fund		10,712,035		—		(317,386)		(317,386)
International Equity Allocation Series Fund		237,183,409		—		(14,365,610)		(14,365,610)

The Funds and Institutional Funds are subject to authoritative guidance related to the accounting and disclosure of uncertain tax positions under U.S. GAAP. This guidance sets forth a minimum threshold for the financial statement recognition of tax positions

35

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

taken based on the technical merits of such positions. United States and non-U.S. tax rules (including the interpretation and application of tax laws) are subject to change. The Funds and Institutional Funds file tax returns and/or adopt certain tax positions in various jurisdictions. Non-U.S. taxes are provided for based on the Funds’ and Institutional Funds’ understanding of the prevailing tax rules of the non-U.S. markets in which they invest. Recently enacted tax rules, including interpretations of tax laws (e.g., guidance pertaining to the U.S. Foreign Account Tax Compliance Act) and tax legislation/initiatives currently under consideration in various jurisdictions, including the U.S., might affect the way the Funds, Institutional Funds and their investors are taxed prospectively and/or retroactively. Prior to the expiration of the relevant statutes of limitations, if any, the Funds and Institutional Funds are subject to examination by U.S. federal, state, local and non-U.S. jurisdictions with respect to the tax returns they have filed and the tax positions they have adopted. The Funds’ and Institutional Funds’ U.S. federal income tax returns are generally subject to examination by the Internal Revenue Service for a period of three years after they are filed. State, local and/or non-U.S. tax returns and/or other filings may be subject to examination for different periods, depending upon the tax rules of each applicable jurisdiction.

Security transactions and related investment income

Security transactions are accounted for in the financial statements on trade date. For purposes of daily net asset value calculations, the Funds’ policy is that security transactions are generally accounted for on the following business day. GMO may override that policy and a Fund may account for security transactions on trade date if it experiences significant purchases or redemptions or engages in significant portfolio transactions. Income dividends and capital gain distributions from the Institutional Funds are recorded on the ex-dividend date. Interest income is recorded on the accrual basis and is adjusted for the amortization of premiums and accretion of discounts. Non-cash dividends, if any, are recorded at the fair market value of the asset received. In determining the net gain or loss on securities sold, the Funds use the identified cost basis.

Expenses and class allocations

Most of the expenses of the Trust are directly attributable to an individual Fund. Investment income, common expenses, if any, and realized and unrealized gains and losses are allocated among the classes of shares of the Funds, if applicable, based on the relative net assets of each class. Each Fund incurs fees and expenses indirectly as a shareholder in the Institutional Funds and the underlying funds. Because the underlying funds owned by the Institutional Funds have different expense and fee levels and the Institutional Funds may own different proportions of the underlying funds at different times, the amount of fees and expenses indirectly incurred by a Fund will vary (see Notes 5 and 11).

State Street Bank and Trust Company (“State Street”) serves as the custodian and fund accounting agent for all Funds except Emerging Countries Series Fund. Brown Brothers Harriman & Co. serves as Emerging Countries Series Fund’s custodian and fund accounting agent. State Street serves as the Funds’ transfer agent. Effective January 1, 2014, any cash balances maintained at the transfer agent are held in a Demand Deposit Account and interest income earned, if any, is shown as interest income in the Statements of Operations.

36

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

3. Investment and other risks

The following chart identifies selected risks associated with each Fund. Risks not marked for a particular Fund may, however, still apply to some extent to that Fund at various times.

	Multi-Asset Class Series  Funds			Equity Series Funds
	Benchmark-Free Allocation Series Fund	Global Asset Allocation Series Fund	Global Equity Allocation Series Fund	International Equity Allocation Series Fund	International Developed Equity Allocation Series Fund	Emerging Countries Series Fund
Commodities Risk	●	●
Counterparty Risk	●	●	●	●	●	●
Credit Risk	●	●	●	●	●
Currency Risk	●	●	●	●	●	●
Derivatives and Short Sales Risk	●	●	●	●	●	●
Focused Investment Risk	●	●	●	●	●	●
Fund of Funds Risk	●	●	●	●	●	●
Futures Contracts Risk	●	●
Illiquidity Risk	●	●	●	●	●	●
Large Shareholder Risk	●	●	●	●	●	●
Leveraging Risk	●	●	●	●	●	●
Management and Operational Risk	●	●	●	●	●	●
Market Disruption and Geopolitical Risk	●	●	●	●	●	●
Market Risk — Asset-Backed Securities	●	●
Market Risk — Equities	●	●	●	●	●	●
Market Risk — Fixed Income Investments	●	●	●	●	●
Merger Arbitrage Risk	●	●
Non-Diversified Funds	●	●	●	●	●	●
Non-U.S. Investment Risk	●	●	●	●	●	●
Small Company Risk	●	●	●	●	●	●

37

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

Investing in mutual funds involves many risks. The risks of investing in a particular Fund depend on the types of investments in its portfolio and the investment strategies GMO employs on its behalf. This section does not describe every potential risk of investing in the Funds. Funds could be subject to additional risks because of the types of investments they make and market conditions, which may change over time.

Because each Fund invests substantially all of its assets in an Institutional Fund, the most significant risks of investing in a Fund are the risks to which the Fund is exposed through its corresponding Institutional Fund (and, in turn, any underlying funds in which the Institutional Fund invests). Those risks include the risks summarized below. Some of the underlying funds are non-diversified investment companies under the 1940 Act and therefore a decline in the market price of a particular security held by those underlying funds may affect performance of those underlying funds more than if they were diversified. In addition to the risks to which each Fund is exposed through investment in its corresponding Institutional Fund, 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 its corresponding Institutional Fund.

References in this section to investments made by a Fund include those made by its corresponding Institutional Fund and any underlying funds.

An investment in a Fund is not a bank deposit and, therefore, is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

• COMMODITIES RISK. Commodity prices can be extremely volatile and are affected by many factors. Exposure to commodities can cause the net asset value of a Fund’s shares to decline or fluctuate in a rapid and unpredictable manner. The value of commodity-related derivatives or indirect investments in commodities may fluctuate more than the commodity, commodities or commodity index to which they relate. See “Derivatives and Short Sales Risk” for a discussion of specific risks of a Fund’s derivatives investments, including commodity-related derivatives.

• COUNTERPARTY RISK. Funds that enter into contracts with counterparties, such as repurchase or reverse repurchase agreements or over-the-counter (“OTC”) derivatives contracts, or that lend their securities run the risk that the counterparty will be unable or unwilling to make timely settlement payments or otherwise honor its obligations. If a counterparty fails to meet its contractual obligations, goes bankrupt, or otherwise experiences a business interruption, the Fund could miss investment opportunities or otherwise hold investments it would prefer to sell, resulting in losses for the Fund. In addition, a Fund may suffer losses if a counterparty fails to comply with applicable laws or other requirements. The Funds are not subject to any limits on their exposure to any one counterparty nor to a requirement that counterparties with whom they enter into contracts maintain a specific rating by a nationally recognized rating organization. Counterparty risk is pronounced during unusually adverse market conditions and is particularly acute in environments (like those of 2008) in which financial services firms are exposed to systemic risks of the type evidenced by the insolvency of Lehman Brothers and subsequent market disruptions.

Participants in OTC derivatives markets typically are not subject to the same level of credit evaluation and regulatory oversight as are members of exchange-based markets, and, therefore, OTC derivatives generally expose a Fund to greater counterparty risk than exchange-traded derivatives. A Fund is subject to the risk that a counterparty will not settle a derivative in accordance with its terms because of a dispute over the terms of the contract (whether or not bona fide) or because of a credit or liquidity problem. If a counterparty’s obligation to a Fund is not collateralized, then the Fund is essentially an unsecured creditor of the counterparty. If a counterparty defaults, the Fund will have contractual remedies (whether or not the obligation is collateralized), but the Fund may be unable to enforce them, thus causing the Fund to suffer a loss. Counterparty risk is greater for derivatives with longer maturities because of the longer time during which events may occur that prevent settlement. Counterparty risk also is greater when a Fund has entered into derivatives contracts with a single or small group of counterparties as it sometimes does as a result of its use of swaps and other OTC derivatives. Funds that use swap contracts are subject, in particular, to the creditworthiness of the counterparties because some types of swap contracts have terms longer than six months (and, in some cases, decades). The creditworthiness of a counterparty may be adversely affected by greater than average volatility in the markets, even if the counterparty’s net market exposure is small relative to its capital. Counterparty risk still exists even if a counterparty’s obligations are secured by collateral because the Fund’s interest in the collateral may not be perfected or additional collateral may not be promptly posted as required. GMO’s view with respect to a particular counterparty is subject to change. The fact, however, that it changes adversely (whether due to external events or otherwise) does not mean a Fund’s existing transactions will necessarily be terminated or modified. Additionally, new transactions may be entered into with a counterparty that is no longer considered a desirable counterparty if the transaction is primarily designed to reduce the overall risk of potential exposure to that counterparty (for example, re-establishing the transaction with a lower notional amount or entering into a countervailing trade with the same counterparty).

38

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

The Funds also are subject to counterparty risk because they execute their securities transactions through brokers and dealers. If a broker or dealer fails to meet its contractual obligations, goes bankrupt, or otherwise experiences a business interruption, the Funds could miss investment opportunities or be unable to dispose of investments they would prefer to sell, resulting in losses for the Funds.

Counterparty risk with respect to derivatives has been and will continue to be affected by new rules and regulations relating to the derivatives market. As described under “Derivatives and Short Sales Risk”, some derivatives transactions are required to be centrally cleared, and a party to a cleared derivatives transaction is subject to the credit risk of the clearing house and the clearing member through which it holds its cleared position. Credit risk of market participants with respect to derivatives that are centrally cleared is concentrated in a few clearing houses, and it is not clear how an insolvency proceeding of a clearing house would be conducted and what impact an insolvency of a clearing house would have on the financial system. Also, in the event of a counterparty’s (or its affiliate’s) insolvency, the Funds’ ability to exercise remedies, such as the termination of transactions, netting of obligations and realization on collateral, could be stayed or eliminated under new special resolution regimes adopted in the United States, the European Union and various other jurisdictions. Such regimes provide governmental authorities with broad authority to intervene when a financial institution is experiencing financial difficulty. In particular, with respect to counterparties who are subject to such proceedings in the European Union, the liabilities of such counterparties to the Funds could be reduced, eliminated, or converted to equity in such counterparties (sometimes referred to as a “bail in”).

• CREDIT RISK. This is 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, or the downgrade of the credit rating of the investment. This risk is particularly acute in environments (like those of 2008) in which financial services firms are exposed to systemic risks of the type evidenced by the insolvency of Lehman Brothers and subsequent market disruptions.

All fixed income securities are subject to credit risk. Financial strength and solvency of an issuer are the primary factors influencing credit risk. The risk varies depending upon whether the issuer is a corporation, a government or government entity, whether the particular security has a priority over other obligations of the issuer in payment of principal and interest and whether it has any collateral backing or credit enhancement. Credit risk may change over the term of a fixed income security. U.S. government securities are subject to varying degrees of credit risk depending upon whether the securities are supported by the full faith and credit of the United States, supported by the ability to borrow from the U.S. Treasury, supported only by the credit of the issuing U.S. government agency, instrumentality, or corporation, or otherwise supported by the United States. For example, issuers of many types of U.S. government securities (e.g., the Federal Home Loan Mortgage Corporation (“Freddie Mac”), Federal National Mortgage Association (“Fannie Mae”), and Federal Home Loan Banks), although chartered or sponsored by Congress, are not funded by Congressional appropriations and their fixed income securities, including mortgage-backed and other asset-backed securities, are neither guaranteed nor insured by the U.S. government. These securities are subject to more credit risk than U.S. government securities that are supported by the full faith and credit of the United States (e.g., U.S. Treasury bonds). Investments in sovereign or quasi-sovereign debt involve the risk that the governmental entities responsible for repayment may be unable or unwilling to pay interest and repay principal when due. A governmental entity’s ability and willingness to pay interest and repay principal in a timely manner may be affected by a variety of factors, including its cash flow, the size of its reserves, its access to foreign exchange, the relative size of its debt service burden to its economy as a whole, and political constraints. Investments in quasi-sovereign issuers are subject to the additional risk that the issuer may default independently of its sovereign. Sovereign debt risk is greater for fixed income securities issued or guaranteed by emerging countries.

In many cases, the credit risk of a fixed income security is reflected in its credit ratings, and a Fund holding a rated security is subject to the risk that the investment’s rating will be downgraded.

Securities issued by the U.S. government historically have presented minimal credit risk. However, events in 2011 led to a downgrade in the long-term credit rating of U.S. bonds by several major rating agencies and introduced greater uncertainty about the repayment by the United States of its obligations. A further credit rating downgrade could decrease, and a default in the payment of principal or interest on U.S. government securities would decrease the value of a Fund’s investments, and increase the volatility of a Fund’s portfolio.

As described under “Market Risk — Asset-Backed Securities”, asset-backed securities may be backed by many types of assets and their payment of interest and repayment of principal largely depend on the cash flows generated by the assets backing them. The

39

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

credit risk of a particular asset-backed security depends on many factors, as described under “Market Risk — Asset-Backed Securities.”

The obligations of issuers also may be subject to bankruptcy, insolvency and other laws affecting the rights and remedies of creditors. A Fund also is exposed to credit risk on a reference security to the extent it writes protection under credit default swaps. See “Derivatives and Short Sales Risk” for more information regarding risks associated with the use of credit default swaps.

The extent to which the market price of a fixed income security changes in response to a credit event depends on many factors and can be difficult to predict. For example, even though the effective duration of a long-term floating rate security is very short, an adverse credit event or change in the perceived creditworthiness of its issuer could cause its market price to decline much more than its effective duration would suggest.

Credit risk is particularly pronounced for below investment grade securities (commonly referred to as “junk bonds”). The sovereign debt of many non-U.S. governments, including their sub-divisions and instrumentalities, is below investment grade. Many asset-backed securities also are below investment grade. Below investment grade securities have speculative characteristics, often are less liquid than higher quality securities, present a greater risk of default and are more susceptible to real or perceived adverse industry conditions. Investments in distressed or defaulted or other low quality debt instruments generally are considered speculative and may involve substantial risks not normally associated with investments in higher quality securities, including adverse business, financial or economic conditions that lead to payment defaults and insolvency proceedings on the part of their issuers. In particular, distressed or defaulted obligations might be repaid, if at all, only after lengthy workout or bankruptcy proceedings, during which the issuer might not make any interest or other payments, and a Fund may incur additional expenses to seek recovery. If GMO’s assessment of the eventual recovery value of a distressed or defaulted debt security proves incorrect, a Fund may lose a substantial portion or all of its investment or it may be required to accept cash or instruments worth less than its original investment. In the event of default of sovereign debt, the Funds may be unable to pursue legal action against the issuer.

• CURRENCY RISK. Currency risk is the risk that fluctuations in exchange rates will adversely affect the market value of a Fund’s investments. Currency risk includes the risk that the currencies in which a Fund’s investments are traded, in which a Fund receives income, or in which a Fund has taken a position, will decline in value relative to the currency in which the Fund is denominated. Currency risk also includes the risk that the currency to which the Fund has obtained exposure through hedging declines in value relative to the currency being hedged, in which event the Fund may realize a loss on both the hedging instrument and the currency being hedged. Currency exchange rates can fluctuate significantly for many reasons. See “Market Disruption and Geopolitical Risk.”

Many of the Funds use derivatives to take currency positions that are under- or over-weighted (in some cases significantly) relative to the currency exposure of their portfolios and their benchmarks. If the exchange rates of the currencies involved do not move as expected, a Fund could lose money on both its holdings of a particular currency and the derivative. See also “Non-U.S. Investment Risk.”

Some currencies are illiquid (e.g., some emerging country currencies), and a Fund may not be able to convert them into U.S. dollars, in which case GMO may decide to purchase U.S. dollars in a parallel market with an unfavorable exchange rate. Exchange rates for many currencies (e.g., some emerging country currencies) are particularly affected by exchange control regulations.

Derivative transactions in foreign currencies (such as futures, forwards, options and swaps) may involve leveraging risk in addition to currency risk, as described under “Leveraging Risk.” In addition, the obligations of counterparties in currency derivative transactions are often not secured by collateral, which increases counterparty risk (see “Counterparty Risk”).

• DERIVATIVES AND SHORT SALES RISK. All of the Funds may invest in derivatives, which are financial contracts whose value depends on, or is derived from, the value of underlying assets, reference rates, or indices. Derivatives involve the risk that their value may not change as expected relative to changes in the value of the assets, rates, or indices they are designed to track. Derivatives include futures contracts, forward contracts, foreign currency contracts, swap contracts, contracts for differences, options on securities and indices, options on futures contracts, options on swap contracts, interest rate caps, floors and collars, reverse repurchase agreements, and other OTC contracts. Derivatives may relate to securities, commodities, currencies, currency exchange rates, interest rates, inflation rates, and indices.

40

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

The use of derivatives involves risks that are in addition to, and potentially greater than, the risks of investing directly in securities and other more traditional assets. In particular, a Fund’s use of OTC derivatives exposes it to the risk that the counterparties will be unable or unwilling to make timely settlement payments or otherwise honor their obligations. An OTC derivatives contract typically can be closed only with the consent of the other party to the contract. If the counterparty defaults, the Fund will still have contractual remedies but may not be able to enforce them. Because the contract for each OTC derivative is individually negotiated, the counterparty may interpret contractual terms (e.g., the definition of default) differently than the Fund, and if it does, the Fund may decide not to pursue its claims against the counterparty to avoid the cost and unpredictability of legal proceedings. The Fund, therefore, may be unable to obtain payments GMO believes are owed to it under OTC derivatives contracts, or those payments may be delayed or made only after the Fund has incurred the cost of litigation.

A Fund may invest in derivatives that (i) do not require the counterparty to post collateral (e.g., foreign currency forwards), (ii) require collateral but that do not provide for the Fund’s security interest in it to be perfected, (iii) require a significant upfront deposit by the Fund unrelated to the derivative’s fundamental fair (or intrinsic) value, or (iv) do not require that collateral be regularly marked-to-market. When a counterparty’s obligations are not fully secured by collateral, a Fund runs a greater risk of not being able to recover what it is owed if the counterparty defaults. Even when derivatives are required by contract to be collateralized, a Fund typically will not receive the collateral for one or more days after the collateral is required to be posted.

The Funds may invest in derivatives with a limited number of counterparties, and events affecting the creditworthiness of any of those counterparties may have a pronounced effect on the Funds. Derivatives risk is particularly acute in environments (like those of 2008) in which financial services firms are exposed to systemic risks of the type evidenced by the insolvency of Lehman Brothers and subsequent market disruptions. In addition, during those periods, a Fund may have a greater need for cash to provide collateral for large swings in its mark-to-market obligations under the derivatives in which it has invested.

Derivatives also present other risks described in this section, including market risk, illiquidity risk, currency risk, credit risk, and counterparty risk. Many derivatives, in particular OTC derivatives, are complex and their valuation often requires modeling and judgment, which increases the risk of mispricing or improper valuation. The pricing models used may not produce valuations that are consistent with the values a Fund realizes when it closes or sells an OTC derivative. Valuation risk is more pronounced when a Fund enters into OTC derivatives with specialized terms because the value of those derivatives in some cases is determined only by reference to similar derivatives with more standardized terms. As a result, incorrect valuations may result in increased cash payments to counterparties, undercollateralization and/or errors in the calculation of a Fund’s net asset value.

A Fund’s use of derivatives may not be effective or have the desired results. Moreover, suitable derivatives will not be available in all circumstances. For example, the economic costs of taking some derivative positions may be prohibitive, and if a counterparty or its affiliate is deemed to be an affiliate of a Fund, the Funds will not be permitted to trade with that counterparty. In addition, GMO may decide not to use derivatives to hedge or otherwise reduce a Fund’s risk exposures, potentially resulting in losses for the Fund.

Swap contracts and other OTC derivatives are highly susceptible to illiquidity risk (see “Illiquidity Risk”) and counterparty risk (see “Counterparty Risk”). These derivatives are also subject to documentation risk, which is the risk that ambiguities, inconsistencies or errors in the documentation relating to a derivative transaction may lead to a dispute with the counterparty or unintended investment results. In addition, see “Commodities Risk” for a discussion of certain risks specific to commodity-related derivatives. Because many derivatives have a leverage component (i.e., a notional value in excess of the assets needed to establish and/or maintain the derivative position), adverse changes in the value or level of the underlying asset, rate or index may result in a loss substantially greater than the amount invested in the derivative itself. See “Leveraging Risk.”

A Fund’s use of derivatives may be subject to special tax rules and could generate additional taxable income for shareholders. In addition, the tax treatment of a Fund’s use of derivatives may be unclear because there is little case or other law interpreting the terms of most derivatives or determining their tax treatment. In addition, the SEC recently proposed a rule under the 1940 Act regulating the use by registered investment companies of derivatives and many related instruments. That rule, if adopted as proposed, would, among other things, restrict a Fund’s ability to engage in derivatives transactions or so increase the cost of derivatives transactions that a Fund would be unable to implement its investment strategy.

Derivatives Regulation. The U.S. government has enacted legislation that provides for new regulation of the derivatives market, including clearing, margin, reporting, and registration requirements. The European Union (and some other countries) are implementing similar requirements, which will affect a Fund when it enters into a derivatives transaction with a counterparty

41

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

organized in that country or otherwise subject to that country’s derivatives regulations. Because these requirements are new and evolving (and some of the rules are not yet final), their ultimate impact remains unclear.

Transactions in some types of swaps (including interest rate swaps and credit default swaps on North American and European indices) are required to be centrally cleared. In a transaction involving those swaps (“cleared derivatives”), a Fund’s counterparty is a clearing house rather than a bank or broker. Since the Funds are not members of clearing houses and only members of a clearing house (“clearing members”) can participate directly in the clearing house, the Funds hold cleared derivatives through accounts at clearing members. In cleared derivatives positions, the Funds make payments (including margin payments) to and receive payments from a clearing house through their accounts at clearing members. Clearing members guarantee performance of their clients’ obligations to the clearing house.

In some ways, cleared derivative arrangements are less favorable to mutual funds than bilateral arrangements, for example, by requiring that funds provide more margin for their cleared derivatives positions. Also, as a general matter, in contrast to a bilateral derivatives position, following a period of notice to a Fund, a clearing member at any time can require termination of an existing cleared derivatives position or an increase in margin requirements above those required at the outset of a transaction. Clearing houses also have broad rights to increase margin requirements for existing positions or to terminate those positions at any time. Any increase in margin requirements or termination of existing cleared derivatives positions by the clearing member or the clearing house could interfere with the ability of a Fund to pursue its investment strategy. Further, any increase in margin requirements by a clearing member could expose a Fund to greater credit risk to its clearing member margin for cleared derivatives positions in excess of a clearing house’s margin requirements typically is held by the clearing member (see “Counterparty Risk”). Also, a Fund is subject to risk if it enters into a derivatives transaction that is required to be cleared (or that GMO expects to be cleared), and no clearing member is willing or able to clear the transaction on the Fund’s behalf. While the documentation in place between the Funds and their clearing members generally provides that the clearing members will accept for clearing all cleared derivatives transactions that are within credit limits (specified in advance) for each Fund, the Funds are still subject to the risk that no clearing member will be willing or able to clear a transaction. In those cases, the position might have to be terminated, and the Fund could lose some or all of the benefit of the position, including loss of an increase in the value of the position and loss of hedging protection. In addition, the documentation governing the relationship between the Funds and clearing members is drafted by the clearing members and generally is less favorable to the Funds than typical bilateral derivatives documentation. For example, documentation relating to cleared derivatives generally includes a one-way indemnity by the Funds in favor of the clearing member for losses the clearing member incurs as the Funds’ clearing member. Also, such documentation typically does not provide the Funds any remedies if the clearing member defaults or becomes insolvent. While futures contracts entail similar risks, the risks may be more pronounced for cleared derivatives due to their more limited liquidity and market history.

Some types of cleared derivatives are required to be executed on an exchange or on a swap execution facility. A swap execution facility is a trading platform where multiple market participants can execute derivatives by accepting bids and offers made by multiple other participants in the platform. While this execution requirement is designed to increase transparency and liquidity in the cleared derivatives market, trading on a swap execution facility can create additional costs and risks for the Funds. For example, swap execution facilities typically charge fees, and if a Fund executes derivatives on a swap execution facility through a broker intermediary, the intermediary may impose fees as well. Also, a Fund may indemnify a swap execution facility, or a broker intermediary who executes cleared derivatives on a swap execution facility on the Fund’s behalf, against any losses or costs that may be incurred as a result of the Fund’s transactions on the swap execution facility. If a Fund wishes to execute a package of transactions that include a swap that is required to be executed on a swap execution facility as well as other transactions (for example, a transaction that includes both a security and an interest rate swap that hedges interest rate exposure with respect to such security), the Fund may be unable to execute all components of the package on the swap execution facility. In that case, the Fund would need to trade some components of the package on the swap execution facility and other components in another manner, which could subject the Fund to the risk that some components would be executed successfully and others would not, or that the components would be executed at different times, leaving the Fund with an unhedged position for a period of time.

The U.S. government and the European Union have adopted mandatory minimum margin requirements for uncleared derivatives. GMO expects that the Funds’ transactions will become subject to variation margin requirements under such rules in 2017 and initial margin requirements under such rules in 2020. Such requirements could increase the amount of margin a Fund needs to provide in connection with its derivatives transactions and, therefore, make derivatives transactions more expensive.

These and other new rules and regulations could, among other things, further restrict a Fund’s ability to engage in, or increase the cost to the Fund of derivatives transactions, for example, by making some types of derivatives no longer available to the Fund, or

42

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

otherwise limiting liquidity. The implementation of the clearing requirement has increased the costs of derivatives transactions for the Funds, since the Funds have to pay fees to their clearing members and are typically required to post more margin for cleared derivatives than they have historically posted for bilateral derivatives. The costs of derivatives transactions are expected to increase further as clearing members raise their fees to cover the costs of additional capital requirements and other regulatory changes applicable to the clearing members, which will take effect when rules imposing mandatory minimum margin requirements on bilateral swaps, as described above, become effective. These rules and regulations are new and evolving, so their potential impact on the Funds and the financial system are not yet known. While the new rules and regulations and central clearing of some derivatives transactions are designed to reduce systemic risk (i.e., the risk that the interdependence of large derivatives dealers could cause them to suffer liquidity, solvency or other challenges simultaneously), there is no assurance that they will achieve that result, and in the meantime, as noted above, central clearing and related requirements expose the Funds to new kinds of costs and risks.

Options. Some GMO Funds, particularly GMO Risk Premium Fund, are permitted to write options. 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 market price of an option also may be adversely affected if the market for the option becomes less liquid. In addition, since an American-style option allows the holder to exercise its rights any time before the option’s expiration, the writer of an American-style option has no control over when it will be required to fulfill its obligations as a writer of the option. (The writer of a European-style option is not subject to this risk because the holder may only exercise the option on its expiration date.) If a GMO Fund writes a call option and does not hold the underlying security or instrument, the Fund’s potential loss is theoretically unlimited.

National securities exchanges generally have established limits on the maximum number of options an investor or group of investors acting in concert may write. GMO Funds and GMO will likely constitute such a group. When applicable, these limits restrict a GMO Fund’s ability to purchase or write options on a particular security.

Unlike exchange-traded options, which are standardized with respect to the underlying instrument, expiration date, contract size, and strike price, the terms of OTC options (i.e., options not traded on exchanges) generally are established through negotiation with the other party to the option contract. While a GMO Fund has greater flexibility to tailor an OTC option, OTC options generally expose a Fund to greater credit risk than exchange-traded options, which are guaranteed by the clearing organization of the exchanges where they are traded. Purchasing and writing put and call options are highly specialized activities and entail greater than ordinary market risks.

Special tax rules apply to a Fund’s transactions in options, which could increase the taxes payable by shareholders. In particular, a Fund’s options transactions potentially could cause a substantial portion of the Fund’s distributions to consist of amounts taxable to shareholders subject to U.S. income tax at ordinary income tax rates. See the Funds’ Prospectus and Statement of Additional Information for more information.

Short Investment Exposure. Some Funds may sell securities or currencies short as part of their investment programs in an attempt to increase their returns or for hedging purposes. Short sales expose a Fund to the risk that it will be required to acquire, convert, or exchange a security or currency to replace the borrowed security or currency when the security or currency sold short has appreciated in value, thus resulting in a loss to the Fund. Purchasing a security or currency to close out a short position can itself cause the price of the security or currency to rise further, thereby exacerbating any losses. A Fund that sells short a security or currency it does not own also may have to pay borrowing fees to a broker and may be required to pay the broker any dividends or interest it receives on a borrowed security. A Fund also 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.

Short sales of securities or currencies a Fund does not own and “short” derivative positions involve forms of investment leverage, and the amount of the Fund’s potential loss is theoretically unlimited. A Fund is subject to increased leveraging risk and other investment risks described in this “Investment and other risks” section to the extent it sells short securities or currencies it does not own or takes “short” derivative positions.

• FOCUSED INVESTMENT RISK. Funds with investments that are focused in particular countries, regions, sectors, industries, or issuers that are subject to the same or similar risk factors and funds with investments whose prices are closely correlated are subject

43

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

to greater overall risk than funds with investments that are more diversified and/or whose prices are not as closely correlated. A Fund that invests in the securities of a small number of issuers has greater exposure to adverse developments affecting those issuers and to a decline in the market price of particular securities than Funds investing in the securities of a larger number of issuers.

Securities, sectors, or companies that share common characteristics are often subject to similar business risks and regulatory burdens, and often react similarly to specific economic, market, political or other developments.

Similarly, Funds having a significant portion of their assets in investments tied economically (or related) to a particular geographic region, country (e.g., Taiwan or Japan) or market (e.g., emerging markets), or to sectors within a region, country or market (e.g., Russian oil), have more exposure to regional and country economic risks than funds making investments throughout the world. The political and economic prospects of one country or group of countries within the same geographic region may affect other countries in that region, and a recession, debt crisis or decline in the value of the currency of one country can spread to other countries. Furthermore, companies in a particular geographic region or country are vulnerable to events affecting other companies in that region or country because they often share common characteristics, are exposed to similar business risks and regulatory burdens, and react similarly to specific economic, market, political or other developments. See also “Non-U.S. Investment Risk.”

Because GMO Resources Fund concentrates its investments in the natural resources sector, it is particularly exposed to adverse developments, including adverse price movements, affecting issuers in the natural resources sector and is subject to greater risks than a fund that invests in a wider range of industries. In addition, the market prices of securities of companies in the natural resources sector are often more volatile than those of securities of companies in other industries. Some of the commodities used as raw materials or produced by these companies are subject to broad price fluctuations as a result of industry-wide supply and demand factors. Companies in the natural resources sector often have limited pricing power over the supplies they purchase and the products they sell, which can affect their profitability, and are often capital-intensive and use significant amounts of leverage. Projects in the natural resources sector may have long setup times, and companies cannot ensure that the market will be favorable at the time the project begins production. Companies in the natural resources sector also may be subject to special risks associated with natural or man-made disasters. In addition, the natural resources sector can be especially affected by political and economic developments, government regulations including changes in tax law or interpretations of law, energy conservation, and the success of exploration projects. Specifically, the natural resource sector can be significantly affected by import controls, worldwide competition and cartels, changes in consumer sentiment and spending, and can be subject to liability for, among other things, environmental damage, depletion of resources, and mandated expenditures for safety and pollution control. GMO Resources Fund’s concentration in the securities of natural resource companies exposes it to the price movements of natural resources to a greater extent than if it were more broadly diversified. Because GMO Resources Fund invests primarily in the natural resources sector, it runs the risk of performing poorly during an economic downturn or a decline in demand for natural resources.

Because GMO Risk Premium Fund can have substantial exposure through a limited number of options contracts and because the Fund’s exposures may relate to relatively few stock indices, the Fund is subject to focused investment risk.

• FUND OF FUNDS RISK. Because each Fund invests substantially all of its assets in an Institutional Fund, which may invest in other GMO Funds, closed-end funds, money market funds, ETFs and other investment companies (for purposes of this risk disclosure, underlying funds), the Funds are exposed to the risk that the Institutional Funds or the underlying funds will not perform as expected. The Funds also are indirectly exposed to all of the risks of an investment in the underlying funds.

Because a Fund bears the fees and expenses of its corresponding Institutional Fund, and the Institutional Fund bears the fees and expenses of the underlying funds in which it invests (absent reimbursement of those fees and expenses), the Fund and its corresponding Institutional Fund will incur additional expenses when investing in underlying funds. In addition, total Fund expenses will increase if an Institutional Fund or its successor increases its fees or incurs additional expenses, or when an Institutional Fund makes a new or further investment in underlying funds with higher fees or expenses than the average fees and expenses of the underlying funds then in the Institutional Fund’s portfolio.

Because some underlying GMO Funds (e.g., many of the GMO Bond Funds) invest a substantial portion of their assets in other GMO Funds (pursuant to an exemptive order obtained from the SEC), the GMO Asset Allocation Funds have more tiers of investments than funds in many other groups of investment companies and therefore may be subject to greater fund of funds risk. In addition, to the extent a Fund and its corresponding Institutional Fund invest in shares of underlying GMO Funds, they are indirectly subject to Large Shareholder Risk because those underlying GMO Funds are more likely to have large shareholders (e.g., other GMO Funds). See “Large Shareholder Risk.”

44

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

Investments in ETFs involve the risk that an ETF’s performance may not track the performance of the index the ETF is designed to track. In addition, ETFs often use derivatives to track the performance of the relevant index, and, therefore, investments in those ETFs are subject to the same derivatives risks discussed in “Derivatives and Short Sales Risk.”

• FUTURES CONTRACTS RISK. The risk of loss to a 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 Fund’s ability to establish and close out positions in futures contracts is subject to the development and maintenance of a liquid secondary market. A liquid secondary market may not exist for any particular futures contract at any particular time and a Fund might be unable to effect closing transactions to terminate its exposure to the contract. In using futures contracts, a Fund is reliant on GMO’s ability to predict market and price movements correctly. The skills needed to use futures contracts successfully are different from those needed for traditional portfolio management. If a 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 in the prices of the Fund’s investments that are the subject of the hedge.

A Fund typically will be required to post margin with its futures commission merchant in connection with its transactions in futures contracts. If the Fund has insufficient cash to meet margin requirements, the Fund may need to sell other investments at disadvantageous times. A Fund may be delayed or prevented from recovering margin or other amounts deposited with a futures commission merchant or futures clearinghouse. For example, in the event of an insolvency of the futures commission merchant, a Fund may not be able to recover all (or any) of the margin it has posted with the futures commission merchant or to realize the value of any increase in the price of its positions. The Commodity Futures Trading Commission (the “CFTC”) and the various exchanges have established limits referred to as “speculative position limits” on the maximum net long or net short positions that any person and certain affiliated entities may hold or control in a particular futures contract. In addition an exchange may impose trading limits on the number of contracts that any person may trade on a particular day. An exchange may order the liquidation of positions found to be in violation of these limits, and it may impose sanctions or restrictions. In addition, the Dodd-Frank Wall Street Reform and Consumer Protection Act requires the CFTC to establish speculative position limits on listed futures and economically equivalent OTC derivatives, which may adversely affect the market liquidity of the futures contracts, options, and economically equivalent derivatives in which a Fund invests. As a result of such limits, positions held by other GMO clients or by GMO or its affiliates may prevent GMO from taking positions on behalf of a Fund in a particular futures contract or OTC derivative.

Futures contracts traded on markets outside the United States generally are not subject to regulation by the CFTC or other U.S. regulators. U.S. regulators neither regulate the activities of a foreign exchange, nor have the power to compel enforcement of the rules of the foreign exchange or the laws of the country in which the exchange is located. Margin and other payments made by a Fund in foreign countries may not have the same protections as payments in the United States. In addition, foreign futures contracts may be less liquid and more volatile than U.S. contracts.

• ILLIQUIDITY RISK. Illiquidity risk is the risk that low trading volume, lack of a market maker, large position size, or legal restrictions (including daily price fluctuation limits or “circuit breakers”) limits or prevents a Fund from selling particular securities or closing derivative positions at desirable prices. In addition to these risks, a Fund is exposed to illiquidity risk when it has an obligation to purchase particular securities (e.g., as a result of entering into reverse repurchase agreements, writing a put, or closing a short position). To the extent a Fund’s investments include asset-backed securities, distressed, defaulted or other low quality debt securities, emerging country debt securities, securities of companies with smaller market capitalizations or smaller total float-adjusted market capitalizations, or emerging market securities, it is subject to increased illiquidity risk. These types of investments can be difficult to value, exposing a Fund to the risk that the price at which it sells them will be less than the price at which they were valued when held by the Fund. Illiquidity risk also may be greater in times of financial stress. For example, Inflation-Protected Securities issued by the U.S. Treasury (“TIPS”) have experienced periods of greatly reduced liquidity during disruptions in fixed income markets, such as the events surrounding the bankruptcy of Lehman Brothers in 2008. Less liquid securities are more susceptible than other securities to price declines when market prices decline generally.

A Fund may buy securities that are less liquid than those in its benchmark.

A Fund’s, and particularly GMO Risk Premium Fund’s, ability to use options as part of its investment program depends on the liquidity of the options market. In addition, that market may not be liquid when a Fund seeks to close out an option position. Also, the hours of trading for options on an exchange may not conform to the hours during which the securities held by a Fund are traded. To the extent that the options markets close before the markets for the underlying securities, significant price and rate movements

45

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

can take place in the markets for underlying securities that are not immediately reflected in the options markets. If a Fund receives a redemption request and is unable to close out an option it has sold, the Fund may temporarily be leveraged in relation to its assets.

• LARGE SHAREHOLDER RISK. To the extent a large number of shares of a Fund is held by a single shareholder (e.g., an institutional investor, financial intermediary, or another GMO Fund) or a group of shareholders with a common investment strategy (e.g., GMO asset allocation accounts), the Fund is subject to the risk that a redemption by those shareholders of all or a large portion of their Fund shares will adversely affect the Fund’s performance by forcing the Fund to sell portfolio securities, potentially at disadvantageous prices, to raise the cash needed to satisfy the redemption request. In addition, GMO Funds and other accounts over which GMO has investment discretion that invest in the Funds are not limited in how often they may purchase or sell Fund shares. The GMO Asset Allocation Funds and separate accounts managed by GMO for its clients hold substantial percentages of the shares of many Funds, and asset allocation decisions by GMO may result in substantial redemptions from (or investments in) those Funds. These transactions may adversely affect the Fund’s performance to the extent that the Fund is required to sell investments (or invest cash) when it would not otherwise do so. Redemptions of a large number of shares also may increase transaction costs or, by necessitating a sale of portfolio securities, have adverse tax consequences for Fund shareholders. Additionally, redemptions and/or purchases of shares by a large shareholder and/or a group of shareholders over time potentially limit the use of any capital loss carryforwards to offset future realized capital gains (if any) and other losses that would otherwise reduce distributable net investment income. Large shareholders may limit or prevent a Fund’s use of tax equalization for U.S. federal tax purposes. In addition, to the extent a Fund invests in other GMO Funds subject to large shareholder risk, the Fund is indirectly subject to this risk.

• LEVERAGING RISK. The use of reverse repurchase agreements and other derivatives and securities lending creates leverage (i.e., a Fund’s investment exposures exceed its net asset value). Leverage increases a Fund’s losses when the value of its investments (including derivatives) declines. Because many derivatives have a leverage component (i.e., a notional value in excess of the assets needed to establish or maintain the derivative position), adverse changes in the value or level of the underlying asset, rate or index may result in a loss substantially greater than the amount invested in the derivative itself. In the case of swaps, the risk of loss generally is related to a notional principal amount, even if the parties have not made any initial investment. Some derivatives have the potential for unlimited loss, regardless of the size of the initial investment. A Fund’s portfolio also will be leveraged if it borrows money to meet redemption requests or settle investment transactions or if it exercises its right to delay payment on a redemption.

A Fund may manage some of its derivative positions by offsetting derivative positions against one another or against other assets. To the extent offsetting positions do not behave in relation to one another as expected, a Fund may perform as if it were leveraged.

• MANAGEMENT AND OPERATIONAL RISK. Each Fund is subject to management risk because it relies on GMO’s ability to achieve its investment objective. Each Fund runs the risk that GMO’s investment techniques will fail to produce desired results and cause the Fund to incur significant losses. GMO also may fail to use derivatives effectively, choosing to hedge or not to hedge positions at disadvantageous times.

For many Funds, 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 a Fund’s performance. The Funds also run the risk that GMO’s assessment of an investment (including a company’s fundamental fair (or intrinsic) value) may be wrong.

There can be no assurance that key GMO personnel will continue to be employed by GMO. The loss of their services could have an adverse impact on GMO’s ability to achieve the Funds’ investment objectives.

The Funds also are subject to the risk of loss as a result of other services provided by GMO and other service providers, including pricing, administrative, accounting, tax, legal, custody, transfer agency, and other services. Operational risk includes the possibility of loss caused by inadequate procedures and controls, human error, and system failures by a service provider. For example, trading delays or errors could prevent a Fund from benefiting from potential investment gains or avoiding losses. In addition, a service provider may be unable to provide a net asset value (“NAV”) for a Fund or share class on a timely basis. GMO is not contractually liable to the Funds for losses associated with operational risk absent its willful misfeasance, bad faith, gross negligence, or reckless disregard of its contractual obligations to provide services to the Funds. Other Fund service providers also have contractual limitations on their liability to the Funds for losses resulting from their errors.

46

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

The Funds and their service providers (including GMO) are susceptible to cyber-attacks and technological malfunctions that may have effects that are similar to those of a cyber-attack. Cyber-attacks include, among others, stealing or corrupting data maintained online or digitally, preventing legitimate users from accessing information or services on a website, releasing confidential information without authorization, and causing operational disruption. Successful cyber-attacks against, or security breakdowns of, a Fund, GMO, a sub-adviser, or a custodian, transfer agent, or other service provider may adversely affect the Fund or its shareholders. For instance, cyber-attacks may interfere with the processing of shareholder transactions, affect a Fund’s ability to calculate its net asset value, cause the release or misappropriation of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject the Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. While GMO has established business continuity plans and systems designed to prevent cyber-attacks, such plans and systems are subject to inherent limitations. Similar types of cyber security risks also are present for issuers of securities in which the Funds invest, which could result in material adverse consequences for such issuers, and may cause a Fund’s investment in such securities to lose value.

• MARKET DISRUPTION AND GEOPOLITICAL RISK. The Funds are subject to the risk that geopolitical and other events (e.g., wars and terrorism) will disrupt securities markets and adversely affect global economies and markets, thereby decreasing the value of the Funds’ investments. Sudden or significant changes in the supply or prices of commodities or other economic inputs (e.g., the marked decline in oil prices that began in late 2014) may have material and unexpected effects on both global securities markets and individual countries, regions, sectors, companies, or industries, which could significantly reduce the value of a Fund’s investments. Terrorism in the United States and around the world has increased geopolitical risk. The terrorist attacks on September 11, 2001 resulted in the closure of some U.S. securities markets for four days, and similar attacks are possible in the future. Securities markets may be susceptible to market manipulation (e.g., the manipulation of the London Interbank Offered Rate (LIBOR)) or other fraudulent trading practices, which could disrupt the orderly functioning of markets or reduce the value of investments traded in them, including investments of the Funds. Instances of fraud and other deceptive practices committed by senior management of certain companies in which a Fund invests may undermine GMO’s due diligence efforts with respect to such companies, and if such fraud is discovered, negatively affect the value of the Fund’s investments. In addition, when discovered, financial fraud may contribute to overall market volatility, which can negatively impact a Fund’s investment program. Financial fraud also may impact the rates or indices underlying a Fund’s investments.

While the U.S. government has always honored its credit obligations, a default by the U.S. government (as has been threatened in recent years) would be highly disruptive to the U.S. and global securities markets and could significantly reduce the value of the Funds’ investments. Similarly, political events within the United States at times have resulted, and may in the future result, in a shutdown of government services, which could adversely affect the U.S. economy, decrease the value of many Fund investments, and increase uncertainty in or impair the operation of the U.S. or other securities markets. Uncertainty surrounding the sovereign debt of several European Union countries, as well as the continued existence of the European Union itself, has disrupted and may continue to disrupt markets in the United States and around the world. If a country changes its currency or leaves the European Union or if the European Union dissolves, the world’s securities markets likely will be significantly disrupted. Substantial government interventions (e.g., currency controls) also could adversely affect the Funds. War, terrorism, economic uncertainty, and related geopolitical events have led, and in the future may lead, to increased short-term market volatility and may have adverse long-term effects on U.S. and world economies and markets generally. Likewise, natural and environmental disasters, such as the earthquake and tsunami in Japan in early 2011, and systemic market dislocations of the kind surrounding the insolvency of Lehman Brothers in 2008, if repeated, would be highly disruptive to economies and markets, adversely affecting individual companies and industries, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of the Funds’ investments. During such market disruptions, the Funds’ exposure to the risks described elsewhere in this “Investment and other risks” section will likely increase. Market disruptions, including sudden government interventions, can also prevent the Funds from implementing their investment programs and achieving their investment objectives. For example, a market disruption may adversely affect the orderly functioning of the securities markets and may cause the Funds’ derivatives counterparties to discontinue offering derivatives on some underlying commodities, securities, reference rates, or indices, or to offer them on a more limited basis. To the extent a Fund has focused its investments in the stock index of a particular region, adverse geopolitical and other events in that region could have a disproportionate impact on the Fund.

• MARKET RISK. All of the Funds are subject to market risk, which is the risk that the market value of their holdings will decline. Market risks include:

Asset-Backed Securities — Investments in asset-backed securities not only are subject to all of the market risks described under “Market Risk — Fixed Income Investments,” but to other market risks as well.

47

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

Asset-backed securities are often exposed to greater risk of severe credit downgrades, illiquidity, and defaults than many other types of fixed income investments. These risks are particularly acute during periods of adverse market conditions, such as those that occurred in 2008. Asset-backed securities may be backed by many types of assets, including pools of residential and commercial mortgages, automobile loans, educational loans, home equity loans, and credit-card receivables. They also may be backed by pools of corporate, sovereign or quasi-sovereign bonds, bank loans to corporations, or a combination of bonds and loans (commonly referred to as “collateralized debt obligations” or “collateralized loan obligations”) and by the fees payable to service providers.

As described under “Market Risk — Fixed Income Investments,” 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 of interest on asset-backed securities and repayment of principal largely depend on the cash flow generated by the assets backing the securities, as well as the deal structure (e.g., the amount of underlying assets or other support available to produce the cash flows necessary to service interest and make principal payments), the quality of the underlying assets, the level of credit support and the credit quality of the credit-support provider, if any, and the reliability of various other service providers with access to the payment stream. A problem in any one of these factors can lead to a reduction in the payment stream GMO expected a Fund to receive at the time the Fund purchased the asset-backed security. Asset-backed securities involve risk of loss of principal if obligors of the underlying obligations default and the value of the defaulted obligations exceeds whatever credit support the securities may have. Asset-backed securities backed by sub-prime mortgage loans, in particular, may expose a Fund to significantly greater declines in value due to defaults because sub-prime mortgage loans are typically made to less creditworthy borrowers and thus have a higher risk of default than conventional mortgage loans. The obligations of issuers (and obligors of asset-backed securities) also are subject to bankruptcy, insolvency and other laws affecting the rights and remedies of creditors. As of the date of this report, many asset-backed securities owned by the Funds that were once rated investment grade are now rated below investment grade. See “Credit Risk” for more information about credit risk.

With the deterioration of worldwide economic and liquidity conditions that occurred and became acute in 2008, the markets for asset-backed securities became fractured, and uncertainty about the creditworthiness of those securities (and underlying assets) caused credit spreads (the difference between yields on asset-backed securities and U.S. Government securities) to widen dramatically. Concurrently, systemic risks of the type evidenced by the insolvency of Lehman Brothers and subsequent market disruptions reduced the ability of financial institutions to make markets in many fixed income securities. These events reduced liquidity and contributed to substantial declines in the market prices of asset-backed and other fixed income securities. These conditions may occur again. Also, government actions and proposals affecting the terms of underlying home and consumer loans, changes in demand for products (e.g., automobiles) financed by those loans, and the inability of borrowers to refinance existing loans (e.g., sub-prime mortgages) have had, and may continue to have, adverse valuation and liquidity effects on asset-backed securities.

The market price of an asset-backed security may depend on the servicing of its underlying assets and is, therefore, subject to risks associated with the negligence or defalcation of its servicer. In some circumstances, the mishandling of documentation for underlying assets also may affect the rights of holders of those underlying assets. The insolvency of an entity that generated the assets underlying an asset-backed security is likely to result in a decline in the market price of that security, as well as costs and delays. The obligations underlying asset-backed securities, in particular securities backed by pools of residential and commercial mortgages, also are subject to unscheduled prepayment, and a Fund may be unable to invest prepayments at as high a yield as was provided by the asset-backed security. When interest rates rise, these obligations also may be repaid more slowly than anticipated, and the market price of the Fund’s investment may decrease.

In addition, the existence of insurance on an asset-backed security does not guarantee that the principal and/or interest will be paid because the insurer could default on its obligations.

The risk of investing in asset-backed securities has increased since the deterioration in worldwide economic and liquidity conditions referred to above because performance of the various sectors in which the assets underlying asset-backed securities are concentrated (e.g., auto loans, student loans, sub-prime mortgages, and credit card receivables) has become more highly correlated. See “Focused Investment Risk” for more information about risks of investing in correlated sectors. A single financial institution may serve as trustee for many asset-backed securities. As a result, a disruption in that institution’s business may have a material impact on many investments. The risks associated with asset-backed securities are particularly pronounced for GMO Opportunistic Income Fund (formerly GMO Debt Opportunities Fund), which has invested a substantial portion of its assets in asset-backed securities, and for each Fund that has invested a substantial portion of its assets in GMO Opportunistic Income Fund (formerly GMO Debt Opportunities Fund).

48

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

Equities — Funds that invest in equities run the risk that the market price of an equity will decline. That decline may be attributable to factors affecting the issuer, such as poor performance by the company’s management or reduced demand for its goods or services, or to factors affecting a particular industry, such as a decline in demand, labor or raw material shortages, or increased production costs. A decline also may result from general market conditions not specifically related to a company or industry, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates, or adverse investor sentiment generally. Equities generally have significant price volatility, and their market prices can decline in a rapid or unpredictable manner. If a 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. The market prices of equities trading at high multiples of current earnings often are more sensitive to changes in future earnings expectations than the market prices of equities trading at lower multiples.

Because of GMO Risk Premium Fund’s emphasis on selling put options on stock indices, GMO expects its net asset value to decline when those indices decline in value. Also, GMO Risk Premium Fund’s investment strategy of writing put options on stock indices can be expected to cause the Fund to underperform relative to those indices when those markets rise sharply because of the Fund’s lack of exposure to the upside of those markets.

Fixed Income Investments. Funds that invest in fixed income securities (including bonds, notes, bills, synthetic debt instruments, and asset-backed securities) are subject to various market risks. 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). In addition, the market price of fixed income investments with complex structures, such as asset-backed securities, and sovereign and quasi-sovereign debt instruments can decline due to uncertainty about their credit quality and the reliability of their payment streams. Some fixed income securities also are subject to unscheduled prepayment, and a Fund may be unable to invest prepayments at as high a yield as was provided by the fixed income security. When interest rates rise, these securities also may be repaid more slowly than anticipated, and the market price of the Fund’s investment may decrease. During periods of economic uncertainty and change, the market price of a Fund’s investments in below investment grade securities (commonly referred to as “junk bonds”) may be particularly volatile. Often below investment grade securities are subject to greater sensitivity to interest rate and economic changes than higher rated bonds and can be more difficult to value, exposing a Fund to the risk that the price at which it sells them will be less than the price at which they were valued when held by the Fund. See “Credit Risk” and “Illiquidity Risk” for more information about these risks.

A risk run by each Fund with a significant investment in fixed income securities is that an increase in prevailing interest rates will cause the market price of those securities to decline. The risk associated with increases in interest rates (also called “interest rate risk”) is generally greater for Funds investing in fixed income securities with longer durations. In addition, in managing some Funds, GMO may seek to evaluate potential investments in part by considering the volatility of interest rates. The value of a Fund’s investments may be significantly reduced if GMO’s assessment proves incorrect.

The extent to which a fixed income security’s price changes with changes in interest rates is referred to as interest rate duration, which can be measured mathematically or empirically. A longer-maturity investment generally has longer interest rate duration because the investment’s fixed rate is locked in for a longer period of time. Floating-rate or adjustable-rate securities, however, generally have shorter interest rate durations because their interest rates are not fixed but rather float up and down as interest rates change. Conversely, inverse floating-rate securities have durations that move in the opposite direction from short-term interest rates and thus tend to underperform fixed rate securities when interest rates rise but outperform them when interest rates decline. Fixed income securities paying no interest, such as zero coupon and principal-only securities, are subject to additional interest rate risk.

The market price of inflation-indexed bonds (including TIPS) typically declines during periods of rising real interest rates (i.e., nominal interest rate minus inflation) and increases during periods of declining real interest rates. In some interest rate environments, such as when real interest rates are rising faster than nominal interest rates, the market price of inflation-indexed bonds may decline more than the price of non-inflation-indexed (or nominal) fixed income bonds with similar maturities.

Generally, when interest rates on short term U.S. Treasury obligations equal or approach zero, a Fund that invests a substantial portion of its assets in U.S. Treasury obligations, such as GMO U.S. Treasury Fund, will have a negative return unless GMO waives or reduces its management fees.

Fixed income securities denominated in foreign currencies also are subject to currency risk. See “Currency Risk.”

49

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

In response to government intervention, economic or market developments, or other factors, fixed income markets may experience periods of high volatility, reduced liquidity or both. During those periods, a Fund could have unusually high shareholder redemptions, requiring it to generate cash by selling securities when it would otherwise not do so, including at unfavorable prices. Fixed income investments may be difficult to value during such periods. In recent periods, central banks and governmental financial regulators, including the U.S. Federal Reserve, have maintained historically low interest rates by purchasing bonds. Steps to curtail or “taper” such activities and other actions by central banks or regulators (such as intervention in foreign currency markets or currency controls) could have a material adverse effect on the Funds.

• MERGER ARBITRAGE RISK. Some Funds may engage in transactions in which a Fund purchases securities at prices below the value of the consideration GMO expects to be paid for them upon consummation of a proposed merger, exchange offer, tender offer, or other similar transaction (“merger arbitrage transactions”). The purchase price paid by the Fund may substantially exceed the market price of the securities before the announcement of the transaction.

If a Fund engages in a merger arbitrage 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. A merger arbitrage transaction can fail for many reasons, including regulatory and antitrust restrictions, political motivations, industry weakness, stock specific events, failed financings, and general market declines.

Merger arbitrage strategies depend for success on the overall volume of merger activity, which has historically been cyclical. When merger activity is low, GMO may be unable to identify enough opportunities to provide sufficient diversification.

Merger arbitrage strategies are subject to the risk of overall market movements, and a Fund may experience losses even if a transaction is consummated. A Fund’s investments in derivatives or short sales of securities to hedge or otherwise adjust long or short investment exposure in connection with a merger arbitrage transaction may not perform as GMO expected or may otherwise reduce the Fund’s gains or increase its losses. Also, a Fund may be unable to hedge against market fluctuations or other risks. In addition, a Fund that sells securities short that GMO expects it to receive upon consummation of a transaction but it does not actually receive (and thus has an unintended “naked” short position) may be required to cover its short position at a time when the securities sold short have appreciated in value, thus resulting in a loss.

• NON-DIVERSIFIED FUNDS. Some of the Funds invest substantially all of their assets in Institutional Funds that are not “diversified” investment companies within the meaning of the 1940 Act. This means the Institutional Funds are allowed to invest in the securities of relatively few issuers. As a result, they may be subject to greater credit, market and other risks, and poor performance by a single issuer may have a greater impact on their performance, than if they were “diversified.”

The following Institutional Funds are not diversified investment companies within the meaning of the 1940 Act:

• GMO Core Plus Bond Fund

• GMO Emerging Countries Fund

• GMO Emerging Country Debt Fund

• GMO Foreign Fund

• GMO Quality Fund

• GMO SGM Major Markets Fund

In addition, each GMO Asset Allocation Fund and each GMO Bond Fund (other than GMO U.S. Treasury Fund) invests a portion of its assets in shares of one or more other GMO Funds that are not diversified investment companies under the 1940 Act. Except as otherwise noted in the Fund summaries of the Institutional Funds’ Prospectus under “Principal investment strategies,” each of the GMO Asset Allocation Funds may invest without limitation in other GMO Funds that are not diversified.

• NON-U.S. INVESTMENT RISK. Funds that invest in non-U.S. securities are subject to more risks than Funds that invest only in U.S. securities. Non-U.S. securities markets often include securities of only a small number of companies in a small number of industries. As a result, the market prices of many of the securities traded on those markets fluctuate more than those of U.S. securities. In addition, issuers of non-U.S. securities often are not subject to as much regulation as U.S. issuers, and the reporting, accounting, custody, and auditing standards to which those issuers are subject differ, in some cases significantly, from U.S. standards. Transactions in non-U.S. securities generally involve higher commission rates, transfer taxes, and custodial costs. In addition, some jurisdictions may limit a Fund’s ability to profit from short-term trading (as defined in the relevant jurisdiction).

50

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

A Fund may be subject to non-U.S. taxation, 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. A Fund may seek a refund of taxes paid, but its efforts may not be successful, in which case the Fund will have incurred additional expenses for no economic benefit. A Fund’s decision to seek a refund is in its sole discretion, and, particularly in light of the cost involved, it may decide not to seek a refund, even if eligible. The outcome of a Fund’s efforts to obtain a refund may be unpredictable. Accordingly, a refund is not typically reflected in a Fund’s net asset value until it is received or until the Fund determines there is a high likelihood the refund will be received. In some cases, the amount of a refund could be material to a Fund’s net assets. Absent a determination that a refund is collectible and free from significant contingencies, such amount is not typically reflected in a Fund’s net assets. For information on possible special Australian or Singapore tax consequences of an investment in the Funds, see the Fund’s Prospectus and Statement of Additional Information for more information.

Also, investing in non-U.S. securities exposes a Fund to the risk of nationalization, expropriation, or confiscatory taxation of assets of their issuers, other government involvement in the economy or in the affairs of specific companies or industries (including in the case of wholly or partially state-owned enterprises), adverse changes in investment regulations, capital requirements or exchange controls (which may include suspension of the ability to transfer currency from a country), and adverse political and diplomatic developments, including the imposition of economic sanctions.

In some non-U.S. securities markets, custody arrangements for securities provide significantly less protection than custody arrangements in U.S. securities markets, and prevailing custody and trade settlement practices (e.g., the requirement to pay for securities prior to receipt) expose a Fund to credit and other risks it does not have in the United States with respect to brokers, custodians, clearing banks or other clearing agents, escrow agents, and issuers. Fluctuations in foreign currency exchange rates also affect the market value of a Fund’s non-U.S. investments (see “Currency Risk”).

The Funds need a license to invest directly in many non-U.S. securities markets. These licenses are often subject to limitations, including maximum investment amounts. Once a license is obtained, a Fund’s ability to continue to invest directly is subject to the risk that the license will be terminated or suspended. If a license to invest in a particular market is terminated or suspended, to obtain exposure to that market the Fund will be required to purchase American Depositary Receipts, Global Depositary Receipts, shares of other funds that are licensed to invest directly, or derivative instruments. The receipt of a non-U.S. license by one of GMO’s clients may preclude other clients, including a Fund, from obtaining a similar license, and this could limit the Fund’s investment opportunities. In addition, the activities of a GMO client could cause the suspension or revocation of a license and thereby limit the Funds’ investment opportunities.

Funds that invest a significant portion of their assets in securities of issuers tied economically to emerging countries (or investments related to emerging markets) are subject to greater non-U.S. investment risk than Funds investing primarily in more developed non-U.S. countries (or markets). The risks of investing in those securities include: greater fluctuations in currency exchange rates; increased risk of default (by both government and private issuers); greater social, economic, and political uncertainty and instability (including the risk of war or natural disaster); increased risk of nationalization, expropriation, or other confiscation of assets of issuers of securities in a Fund’s portfolio; greater governmental involvement in the economy or in the affairs of specific companies or industries (including in the case of wholly or partially state-owned enterprises); less governmental supervision and regulation of the securities markets and participants in those markets; controls on non-U.S. investment, capital controls and limitations on repatriation of invested capital, dividends, interest and other income and on a Fund’s ability to exchange local currencies for U.S. dollars; inability to purchase and sell investments or otherwise settle security or derivative transactions (i.e., a market freeze); unavailability of currency hedging techniques; differences in, or lack of, auditing and financial reporting standards and resulting unavailability of material information about issuers; slower clearance and settlement; difficulties in obtaining and enforcing legal judgments; and significantly smaller market capitalizations of issuers. In addition, the economies of emerging countries may be predominantly based on only a few industries or dependent on revenues from particular commodities.

• SMALL COMPANY RISK. Companies with smaller market capitalizations 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 smaller group of key employees as compared to larger companies. In addition, their securities 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 risk and illiquidity risk are particularly pronounced for securities of these companies.

51

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

Temporary Defensive Positions

Temporary defensive positions are positions that are inconsistent with a Fund’s principal investment strategies and are taken in response to adverse market, economic, political, or other conditions. The Funds normally do not take temporary defensive positions. To the extent a Fund takes a temporary defensive position, or otherwise holds cash, cash equivalents, or high quality debt investments on a temporary basis, the Fund may not achieve its investment objective.

The following paragraphs provide additional information about whether, and to what extent, the Institutional Funds and certain other GMO Funds take temporary defensive positions.

GMO Benchmark-Free Allocation Fund, GMO Benchmark-Free Fund, GMO Implementation Fund and the GMO Bond Funds (other than GMO Emerging Country Debt Fund and GMO U.S. Treasury Fund) may take temporary defensive positions if deemed prudent by GMO. Many of the GMO Bond Funds have previously taken temporary defensive positions.

To the extent a Fund takes a temporary defensive position, or otherwise holds cash, cash equivalents or high quality debt instruments on a temporary basis, the Fund may not achieve its investment objective.

4. Derivative financial instruments

At February 28, 2017, the Funds held no derivative financial instruments directly. For a listing of derivative financial instruments held by the Institutional Funds or underlying funds, if any, as well as the uses of derivative financial instruments by the Institutional Funds or underlying funds, if any, please refer to the Institutional Funds’ or underlying funds’ most recent financial statements.

5. Fees and other transactions with affiliates

Expenses

Shareholders of the Funds do not pay any transaction-based expenses directly to the Fund, as shares of the Fund are sold without an initial sales charge or a contingent deferred sales charge upon redemption. Certain Institutional Funds and underlying funds charge purchase premiums and/or redemption fees. These amounts are retained by the relevant Institutional Fund or underlying fund to help offset estimated portfolio transaction costs and other related costs (e.g., bid to ask spreads, stamp duties and transfer fees) incurred by the Institutional Fund or underlying fund as a result of the purchase or redemption by allocating estimated transaction costs to the purchasing or redeeming shareholder. An Institutional Fund or underlying fund may impose a new purchase premium and/or redemption fee or modify an existing fee at any time. To the extent that a Fund invests in an Institutional Fund that charges purchase premiums and/or redemption fees, the Fund will pay those costs when it buys and sells shares of the Institutional Fund.

The costs of managing, administering, and operating the Fund are spread among each class of shares. These costs cover such things as a Fund’s allocable share of the expenses of its corresponding Institutional Fund and administration and certain other fees and expenses (e.g., state registration fees) of the Fund. See the “Indirect expenses” table in Note 11 for more information.

Management Fees

The Funds do not charge a management fee directly, but each Fund indirectly bears the management fees of its corresponding Institutional Fund and/or underlying funds in which the Institutional Fund invests.

Administration Fees

Each Fund pays GMO an administration fee equal to 0.20% of that Fund’s average daily net asset value; provided that if a Fund invests substantially all of its assets in Class III shares of an Institutional Fund, such fee shall be reduced to an annual rate of 0.05%, and provided further that if a Fund invests substantially all of its assets in a class of shares of an Institutional Fund other than Class III shares, such fee rate shall be reduced by the shareholder service fee rate charged by that class of shares of the Institutional Fund. Administrative services provided by GMO may include, without limitation: processing aggregated purchase and redemption orders for shareholders of record; coordinating operation of the National Security Clearing Corporation’s Fund/SERV system with intermediary platforms; providing information about and processing dividend payments; assisting with the production and distribution of shareholder communications to shareholders of record such as proxies, shareholder reports, and dividend and tax notices; preparing tax returns and related documentation; assisting with the production of registration statements; paying the Trust’s registration fees pursuant to Section 24(f)(2) of the 1940 Act; providing assistance with respect to the audits of the Funds; establishing and maintaining certain information about the shares on an internet site; maintaining certain of the Trust’s records; preparing and submitting reports to various regulatory agencies; preparing and submitting reports and meeting materials to the

52

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

Trustees of the Trust and to existing shareholders; supervising, negotiating, and administering contractual arrangements with (to the extent appropriate) and monitoring the performance of, third-party accounting agents, custodians, depositories, transfer agents, pricing agents, independent accountants and auditors, attorneys, printers, insurers, and other persons in any capacity deemed to be necessary or desirable to Trust or Fund operations and paying for the expenses of such service providers (excluding any sub-transfer agent/recordkeeping payments, whether paid pursuant to the Trust’s Rule 12b-1 Plan or otherwise); providing direct client service, maintenance, and reporting to platform sponsors, retirement plans, and other shareholders of record, such services to include, without limitation, professional and informative reporting, recordholder account information, access to analysis and explanation of Fund reports, and assistance in the correction and maintenance of recordholder account information, and otherwise maintaining the relationships with the recordholders; furnishing office space and equipment, providing bookkeeping and clerical services (excluding determination of net asset value, shareholder services, and fund accounting services for the Fund being supplied by other service providers as the Fund may engage from time to time); and providing individuals affiliated with GMO to serve as officers of the Trust and paying all salaries, fees, and expenses of such officers and Trustees who are affiliated with GMO. GMO has retained State Street Bank to assist it in providing administrative support services.

Sub-transfer Agent/Recordkeeping Payments

Sub-transfer agent/recordkeeping payments are made by Class R4 and Class R5 shares of the Funds to unaffiliated third parties (e.g., financial intermediaries) for providing sub-transfer agency, recordkeeping, and other administrative services to retirement plan participants and other investors who hold shares of the Funds through an omnibus account. Class R4 shares pay for sub-transfer agent/recordkeeping services at an annual rate of 0.25% of Class R4’s average daily net assets. Class R4 is offered but has no shareholders as of February 28, 2017. Class R5 shares pay for sub-transfer agent/recordkeeping services at an annual rate of 0.10% of Class R5’s average daily net assets. Class R5 is offered but has no shareholders as of February 28, 2017. Class R6 shares do not make payments to third parties for sub-transfer agent/recordkeeping services. Sub-transfer agent/recordkeeping payments by Class R4 and Class R5 shares are made pursuant to a distribution and service plan under Rule 12b-1.

Expense Reimbursement

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

6. Purchases and sales of securities

Cost of purchases and proceeds from sales of securities, excluding short-term investments and including GMO U.S. Treasury Fund, if applicable, for the year ended February 28, 2017 are noted in the table below:

Fund Name	Purchases ($) U.S. Government Securities		Purchases ($) Investments (Non-U.S. Government Securities)		Sales ($) U.S. Government Securities		Sales ($) Investments (Non-U.S. Government Securities)
Benchmark-Free Allocation Series Fund		—		83,361,755		—		78,949,107
Emerging Countries Series Fund		—		1,665,921		—		1,150,124
Global Asset Allocation Series Fund		—		4,623,951		—		139,002,010
Global Equity Allocation Series Fund		—		1,962,534		—		2,100,080
International Developed Equity Allocation Series Fund		—		1,031,302		—		240,808
International Equity Allocation Series Fund		—		7,244,066		—		45,988,588

7. Guarantees

In the normal course of business the Funds enter into contracts with third-party service providers that contain a variety of representations and warranties and that provide general indemnifications. The Funds’ maximum exposure under these arrangements is unknown, as it involves possible future claims that may or may not be made against the Funds. Based on experience, GMO is of the view that the risk of loss to the Funds in connection with the Funds’ indemnification obligations is remote; however, there can be no assurance that such obligations will not result in material liabilities that adversely affect the Funds.

53

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

8. Principal shareholders and related parties as of February 28, 2017

Fund Name	Number of shareholders that held more than 10% of the outstanding shares of the Fund		Percentage of outstanding shares of the Fund held by those shareholders owning greater than 10% of the outstanding shares of the Fund
Benchmark-Free Allocation Series Fund		4		70.05%
Emerging Countries Series Fund		1		100.00%
Global Asset Allocation Series Fund		2		94.70%
Global Equity Allocation Series Fund		3		100.00%
International Developed Equity Allocation Series Fund		1		100.00%
International Equity Allocation Series Fund		2		87.78%

9. Share transactions

The Declaration of Trust permits each Fund to issue an unlimited number of shares of beneficial interest (without par value). Transactions in the Funds’ shares were as follows:

	Year Ended February 28, 2017							Year Ended February 29, 2016
	Shares			Amount				Shares			Amount
Benchmark-Free Allocation Series Fund
Class R6:
Shares sold		11,658,720			$	114,996,121			14,386,999			$	144,905,477
Shares issued to shareholders in reinvestment of distributions		342,402				3,280,214			980,562				9,698,231
Shares repurchased		(11,625,299	)			(110,782,881	)		(12,351,878	)			(123,795,601	)
Net increase (decrease)		375,823			$	7,493,454			3,015,683			$	30,808,107
Emerging Countries Series Fund
Class R6:
Shares sold		290,011			$	2,567,078			182,301			$	1,564,385
Shares issued to shareholders in reinvestment of distributions		16,272				140,103			37,404				286,579
Shares repurchased		(257,223	)			(2,159,749	)		(383,973	)			(3,210,277	)
Net increase (decrease)		49,060			$	547,432			(164,268	)		$	(1,359,313	)
Global Asset Allocation Series Fund
Class R6:
Shares sold		2,163,430			$	18,769,049			3,515,547			$	35,128,082
Shares issued to shareholders in reinvestment of distributions		552,245				4,759,069			6,576,381				58,797,323
Shares repurchased		(18,216,743	)			(159,046,353	)		(49,306,025	)			(518,256,926	)
Net increase (decrease)		(15,501,068	)		$	(135,518,235	)		(39,214,097	)		$	(424,331,521	)
Global Equity Allocation Series Fund
Class R6:
Shares sold		344,462			$	3,205,595			366,984			$	3,716,399
Shares issued to shareholders in reinvestment of distributions		72,746				668,575			152,795				1,426,388
Shares repurchased		(431,491	)			(4,014,670	)		(492,690	)			(4,892,766	)
Net increase (decrease)		(14,283	)		$	(140,500	)		27,089			$	250,021

54

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

	Year Ended February 28, 2017							Year Ended February 29, 2016
	Shares			Amount				Shares			Amount
International Developed Equity Allocation Series Fund
Class R6:
Shares sold		155,081			$	1,443,061			135,324			$	1,308,938
Shares issued to shareholders in reinvestment of distributions		41,482				377,438			37,301				351,479
Shares repurchased		(117,247	)			(1,090,983	)		(121,032	)			(1,267,849	)
Net increase (decrease)		79,316			$	729,516			51,593			$	392,568
International Equity Allocation Series Fund
Class R5:#
Shares sold		56,628			$	474,068			164,096			$	1,555,173
Shares issued to shareholders in reinvestment of distributions		—				—			155,756				1,339,144
Shares repurchased		(1,952,766	)			(16,165,800	)		(432,727	)			(4,056,030	)
Net increase (decrease)		(1,896,138	)		$	(15,691,732	)		(112,875	)		$	(1,161,713	)
Class R6:
Shares sold		2,614,090			$	21,889,476			3,051,023			$	26,362,030
Shares issued to shareholders in reinvestment of distributions		859,090				7,271,019			2,107,075				18,113,669
Shares repurchased		(6,131,370	)			(52,196,642	)		(1,966,839	)			(19,055,226	)
Net increase (decrease)		(2,658,190	)		$	(23,036,147	)		3,191,259			$	25,420,473

# Class R5 liquidated on May 20, 2016.

10. Investments in affiliated issuers

A summary of the Funds’ transactions in the shares of the Institutional Funds during the year ended February 28, 2017 is set forth below:

Fund Affiliate	Value, beginning of period			Purchases			Sales Proceeds			Dividend Income			Distributions of Realized Gains			Value, end of period
Benchmark-Free Allocation Series Fund
GMO Benchmark-Free Allocation Fund, Class III		$	266,489,574		$	83,361,755		$	78,949,107		$	3,424,085		$	—		$	293,074,743
Emerging Countries Series Fund
GMO Emerging Countries Fund, Class III		$	9,078,518		$	1,665,921		$	1,150,124		$	146,755		$	—		$	12,626,796
Global Asset Allocation Series Fund
GMO Global Asset Allocation Fund, Class III		$	286,132,190		$	4,623,951		$	139,002,010		$	4,623,951		$	—		$	178,150,315
Global Equity Allocation Series Fund
GMO Global Equity Allocation Fund, Class III		$	12,829,283		$	1,962,534		$	2,100,080		$	446,104		$	262,437		$	14,738,102
International Developed Equity Allocation Series Fund
GMO International Developed Equity Allocation Fund, Class III		$	8,491,472		$	1,031,302		$	240,808		$	384,204		$	—		$	10,394,649
International Equity Allocation Series Fund
GMO International Equity Allocation Fund, Class III		$	224,703,420		$	7,244,066		$	45,988,588		$	7,244,066		$	—		$	222,817,799

55

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

11. Institutional Fund information

Valuation

Shares of the Institutional Funds and other open-end registered investment companies are valued at their most recent net asset value. Direct investments held by the Institutional Funds and underlying funds are valued as follows: Exchange-traded securities (other than exchange-traded options) for which market quotations are readily available are valued at (i) the last sale price or (ii) official closing price or (iii) most recent quoted price published by the exchange (if no reported last sale or official closing price) or (iv) the quoted price provided by a pricing source (in the event GMO deems the private market to be a more reliable indicator of market value than the exchange). Exchange-traded options are valued at the last sale price, provided that price is between the closing bid and ask prices. If the last sale price is not within this range, then they will be valued at the closing bid price for long positions and the closing ask price for short positions. Cleared derivatives are valued using the price quoted (which may be based on a model) by the relevant clearing house. If an updated quote for a cleared derivative is not available by the time that a Fund calculates its net asset value on any business day, then that derivative will generally be valued using an industry standard model, which may differ from the model used by the relevant clearing house. OTC derivatives are generally valued at the price determined by an industry standard model. Unlisted securities for which market quotations are readily available are generally valued at the most recent quoted price. If quotations are not readily available or circumstances make an existing valuation methodology or procedure unreliable, derivatives and other securities are valued at fair value as determined in good faith by the Trustees of GMO Trust (the “Institutional Trustees”) or persons acting at their direction pursuant to procedures approved by the Institutional Trustees. Because of the uncertainty inherent in pricing, and in particular fair value pricing, the value determined for a particular security may be materially different from the value realized upon its sale. See the table below for information about the Institutional Funds’ and underlying funds’ investments in securities and derivatives, if any, that were fair valued using methods determined in good faith by or at the direction of the Institutional Trustees. The Institutional Funds and/or the underlying funds classify such securities as Level 3. Levels are defined in Note 2. For the year ended February 28, 2017, the Institutional Funds did not reduce the value of any of their OTC derivatives contracts, if any, based on the creditworthiness of their counterparties.

The foregoing valuation methodologies are modified for equities that trade in non-U.S. securities markets which close prior to the close of the New York Stock Exchange (“NYSE”) due to time zone differences, including the value of equities that underlie futures, options and other derivatives (to the extent the market for those derivatives closes prior to the close of the NYSE). In those cases, the price will generally be adjusted, to the extent practicable and available, based on inputs from an independent pricing service approved by the Institutional Trustees that are intended to reflect valuation changes through the NYSE close. The table below shows the percentage of net assets of the Institutional Funds’ and underlying funds’ investments in securities and derivatives that were valued using fair value inputs obtained from that independent pricing service as of February 28, 2017. These securities listed on foreign exchanges (including the value of equity securities that underlie futures, options and other derivatives (to the extent the market for such instruments closes prior to the close of the NYSE)) are classified as Level 2. Levels are defined in Note 2.

Typically, the Institutional Funds and underlying funds value fixed income securities at the most recent price supplied by a specific relevant pricing source determined by GMO. Although GMO normally does not evaluate pricing sources for the Institutional Funds or underlying funds on a day-to-day basis, it does evaluate pricing sources on an ongoing basis and may change a pricing source at any time. GMO monitors erratic or unusual movements (including unusual inactivity) in the prices supplied for a security and has discretion to override a price supplied by a source (e.g., by taking a price supplied by another) when it believes that the price supplied is not reliable. Alternative pricing sources are often but not always available for securities held by the Institutional Funds and underlying funds. See the table below for information about securities for which no alternative pricing source was available.

“Quoted price” typically means the bid price for securities held long and the ask price for securities sold short. If a market quotation for a security does not involve a bid or an ask, the “quoted price” may be the price provided by a market participant or other third-party pricing source in accordance with the market practice for that security. If an updated quoted price for a security is not available by the time that an Institutional Fund or underlying fund calculates its net asset value on any business day, the Institutional Fund or underlying fund will generally use the last quoted price so long as GMO believes that the last quoted price continues to represent that security’s fair value.

In the case of derivatives, prices determined by a model may reflect an estimate of the average of bid and ask prices, regardless of whether an Institutional Fund or underlying fund has a long position or a short position.

56

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

As discussed above, the Institutional Funds and underlying funds invest in securities and/or derivatives which may have been fair valued using methods determined in good faith by or at the direction of the Institutional Trustees, fair valued using inputs obtained from an independent pricing service, or valued using prices for which no alternative pricing source was available. The table below presents securities and/or derivatives on a net basis, based on market values or unrealized appreciation/(depreciation), which will tend to understate the Institutional Funds’ or underlying funds’ exposure. The net aggregate indirect exposure to these valuation methodologies (based on each Fund’s net assets) as of February 28, 2017 is as follows:

Securities and derivatives

Fund Name	Fair valued using methods determined in good faith by or at the direction of the Trustees		Fair valued using inputs obtained from an independent pricing service (Net)		Single source; No alternative pricing source was available		Level 3 securities and derivatives
Benchmark-Free Allocation Series Fund		< 1%		30%		1%		1%
Emerging Countries Series Fund		< 1%		83%		—		< 1%
Global Asset Allocation Series Fund		< 1%		36%		< 1%		1%
Global Equity Allocation Series Fund		< 1%		61%		—		< 1%
International Developed Equity Allocation Series Fund		< 1%		95%		—		< 1%
International Equity Allocation Series Fund		< 1%		93%		—		< 1%

Indirect expenses

The Funds incur fees and expenses indirectly as a shareholder in the Institutional Funds and through their indirect exposure to the underlying funds, if any. For the year ended February 28, 2017, these indirect fees and expenses expressed as a percentage of the Fund’s average daily net assets were as follows:

Fund Name	Indirect Net Expenses (excluding shareholder service fees)		Indirect Shareholder Service Fees		Indirect Interest Expense		Total Indirect Expenses
Benchmark-Free Allocation Series Fund		0.655%		0.150%		0.037%*		0.842%
Emerging Countries Series Fund		1.052%		0.148%		0.000%		1.200%
Global Asset Allocation Series Fund		0.411%		0.061%		0.001%		0.473%
Global Equity Allocation Series Fund		0.506%		0.069%		0.000%		0.575%
International Developed Equity Allocation Series Fund		0.533%		0.085%		0.000%		0.618%
International Equity Allocation Series Fund		0.606%		0.078%		0.000%		0.684%

* Includes indirect dividend expense.

57

GMO Series Trust

Notes to Financial Statements — (Continued)

February 28, 2017

Other information

For the year ended February 28, 2017, the portfolio turnover of the Institutional Funds was as follows:

Institutional Fund Name	Portfolio Turnover
Benchmark-Free Allocation Fund		7%
Emerging Countries Fund		86%
Global Asset Allocation Fund		19%
Global Equity Allocation Fund		27%
International Developed Equity Allocation Fund		10%
International Equity Allocation Fund		7%

As of February 28, 2017, the premium on cash purchases and fee on cash redemptions for the Institutional Funds were as follows:

	Benchmark-Free Allocation Fund	Emerging Countries Fund	Global Asset Allocation Fund	Global Equity Allocation Fund	International Developed Equity Allocation Fund	International Equity Allocation Fund
Purchase Premium	0.20%	—	0.15%	0.18%	0.08%	0.25%
Redemption Fee	0.20%	—	0.15%	0.18%	0.08%	0.25%

12. Subsequent events

Subsequent to February 28, 2017, GMO Global Equity Allocation Series Fund received redemption requests in the amount of $3,916,756.

58

Report of Independent Registered Public Accounting Firm

To the Trustees of GMO Series Trust and Shareholders of

GMO Benchmark-Free Allocation Series Fund, GMO Emerging Countries Series Fund, GMO Global Asset Allocation Series Fund, GMO Global Equity Allocation Series Fund, GMO International Developed Equity Allocation Series Fund, and GMO International Equity Allocation Series Fund:

In our opinion, the accompanying statements of assets and liabilities, including the schedules of investments, and the related statements of operations and of changes in net assets and the financial highlights present fairly, in all material respects, the financial position of the GMO Benchmark-Free Allocation Series Fund, GMO Emerging Countries Series Fund, GMO Global Asset Allocation Series Fund, GMO Global Equity Allocation Series Fund, GMO International Developed Equity Allocation Series Fund, and GMO International Equity Allocation Series Fund (the “Funds”) as of February 28, 2017, the results of each of their operations for the year then ended, the changes in each of their net assets for each of the two years in the period then ended and the financial highlights for each of the periods indicated, in conformity with accounting principles generally accepted in the United States of America. These financial statements and financial highlights (hereafter referred to as “financial statements”) are the responsibility of the Fund’s management. Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits of these financial statements in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. Our procedures included confirmation of securities owned as of February 28, 2017 by correspondence with the custodians and brokers; when replies were not received from brokers, we performed other auditing procedures. We believe that our audits provide a reasonable basis for our opinion.

PricewaterhouseCoopers LLP

Boston, Massachusetts

April 26, 2017

59

GMO Series Trust

Fund Expenses

February 28, 2017 (Unaudited)

Expense Examples: The following information is in relation to expenses for the six month period ended February 28, 2017.

As a shareholder of the Funds, you may incur two types of costs: (1) transaction costs; and (2) ongoing costs, including indirect management fees, indirect shareholder service fees, and distribution (12b-1) fees for Funds with Class R5 shares, if applicable, and other Fund expenses. This example is intended to help you understand your ongoing costs (in U.S. dollars) of investing in the Funds and to compare these costs with the ongoing costs of investing in other mutual funds.

These examples are based on an investment of $1,000 invested at the beginning of the period and held for the entire period, September 1, 2016 through February 28, 2017.

Actual Expenses

This section of the table for each class below provides information about actual account values and actual expenses. You may use the information in this section, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, a $10,000,000 account value divided by $1,000 = 10,000), then multiply the result by the number under the heading entitled “Expenses Paid During the Period” to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes

This section of the table for each class below provides information about hypothetical account values and hypothetical expenses based on the Funds’ actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the Funds’ actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the Funds with other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of other funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transactional costs, such as purchase premium and redemption fees. Therefore, this section of the table is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. In addition, if these transactional costs were included, your costs would have been higher.

	Actual						Hypothetical
	Beginning Account Value September 1, 2016		Ending Account Value February 28, 2017		Expenses Paid During the Period*		Beginning Account Value September 1, 2016		Ending Account Value February 28, 2017		Expenses Paid During the Period*		Annualized Expense Ratio
Benchmark-Free Allocation Series Fund
Class R6		$1,000.00		$1,033.30		$4.49		$1,000.00		$1,020.38		$4.46		0.89%
Emerging Countries Series Fund
Class R6		$1,000.00		$1,070.80		$6.26		$1,000.00		$1,018.74		$6.11		1.22%
Global Asset Allocation Series Fund
Class R6		$1,000.00		$1,037.00		$2.63		$1,000.00		$1,022.22		$2.61		0.52%
Global Equity Allocation Series Fund
Class R6		$1,000.00		$1,068.70		$3.18		$1,000.00		$1,021.72		$3.11		0.62%
International Developed Equity Allocation Series Fund
Class R6		$1,000.00		$1,055.90		$3.42		$1,000.00		$1,021.47		$3.36		0.67%
International Equity Allocation Series Fund
Class R6		$1,000.00		$1,057.10		$3.72		$1,000.00		$1,021.17		$3.66		0.73%

* Expenses are calculated using each class’s annualized net expense ratio (including indirect expenses incurred) for the six months ended February 28, 2017, multiplied by the average account value over the period, multiplied by 181 days in the period, divided by 365 days in the year.

60

GMO Series Trust

Tax Information for the Tax Year-Ended February 28, 2017 (Unaudited)

The following information is being provided in order to meet reporting requirements set forth by the Code and/or to meet state-specific requirements. Shareholders should consult their tax advisors.

With respect to distributions paid, the Funds designate the following amounts (or, if subsequently determined to be different, the maximum amount allowable) for the fiscal year-ended February 28, 2017:

Fund Name	Dividend Received Deduction (corporate shareholders)(1)		Qualified Dividend Income (non-corporate shareholders) (1)		U.S. Government Obligation Income(1,2)		Interest- Related Dividend Income(3) ($)		Long- Term Capital Gain Dividends ($)		Foreign Taxes Paid(4) ($)		Foreign Source Income(4) ($)
Benchmark-Free Allocation Series Fund		15.58%		79.15%		13.77%		404,830		—		—		—
Emerging Countries Series Fund		—		100.00%		—		—		—		49,748		189,850
Global Asset Allocation Series Fund		16.98%		67.47%		2.26%		927,755		—		308,723		2,625,006
Global Equity Allocation Series Fund		32.00%		100.00%		—		—		233,197		40,693		348,475
International Developed Equity Allocation Series Fund		—		100.00%		—		—		—		44,051		421,488
International Equity Allocation Series Fund		—		100.00%		—		—		—		976,260		8,219,841

(1) Presented as a percentage of net investment income and short-term capital gain distributions paid, if any.

(2) All or a portion of these amounts may be exempt from taxation at the state level.

(3) These amounts are generally exempt from U.S. withholding taxes for non-U.S. shareholders, provided certain conditions are satisfied by both the Funds and the Funds’ shareholders. If applicable, interest related dividend amounts could include short-term capital gain dividends received from Institutional Funds.

(4) The Funds expect to elect to treat foreign taxes attributed to foreign source income from certain of its investments, as if incurred directly by the Funds’ shareholders.

In early 2018, the Funds will notify applicable shareholders of amounts for use in preparing 2017 U.S. federal income tax forms.

61

Trustees and Officers (Unaudited)

The following tables present information regarding each Trustee and officer of the Trust as of February 28, 2017. Each Trustee’s and officer’s year of birth (“YOB”) is set forth after his or her name. Unless otherwise noted, (i) each Trustee and officer has engaged in the principal occupation(s) noted in the table for at least the most recent five years, although not necessarily in the same capacity, and (ii) the address of each Trustee and officer is c/o GMO Series Trust, 40 Rowes Wharf, Boston, MA 02110. Each Trustee serves in office for a term of eight years or, if sooner, until the Trustee dies, resigns or is removed, or until the election and qualification of the Trustee’s successor. Each officer serves in office until his or her successor is elected and determined to be qualified to carry out the duties and responsibilities of the office, or until the officer resigns or is removed from office.

Management of the Series Trust

Independent Trustees
Name and Year of Birth	Position(s) Held with the Trust	Length of Time Served	Principal Occupation(s) During Past 5 Years	Number of Portfolios in Fund Complex1 Overseen		Other Directorships Held in the Past Five Years
Maria D. Furman YOB: 1954	Trustee	Since August 2011.	Retired.		12	Trustee of MassMutual Premier Funds, MassMutual Select Funds, MML Series Investment Fund, and MML Series Investment Fund II (93 portfolios); and Board of Managers for Cambridge Associates Fiduciary Trust LLC.
Sandra Whiston YOB: 1947	Trustee	Since November 2011.	Retired (2008 – present); Head of Institutional Management, Putnam Investments (2005 – 2008).		12	None.
Interested Trustee And Officer
Joseph B. Kittredge, Jr.2 YOB: 1954	Chairman of the Board of Trustees	Chairman of the Board of Trustees since November 2011; Trustee since May 2011; President and Chief Executive Officer of the Trust, May 2011 – October 2013.	General Counsel, Grantham, Mayo, Van Otterloo & Co. LLC (2005 – present); Partner, Ropes & Gray, LLP (1988 – 2005).		48	None.

¹  The Fund Complex includes series of each of GMO Trust and GMO Series Trust. Mr. Kittredge also serves as a Trustee of GMO Trust.

²  Mr. Kittredge is an “interested person” of the Trust, as such term is used in the 1940 Act (an “Interested Trustee”), by virtue of his position with GMO indicated in the table above and his interest as a member of GMO.

62

Officers
Name and Year of Birth	Position(s) Held with the Trust	Length of Time Served	Principal Occupation(s) During Past 5 Years*
Sheppard N. Burnett YOB: 1968	President and Chief Executive Officer	President since October 2013; Chief Executive Officer since October 2013; Chief Financial Officer, May 2011 –October 2013; Treasurer, May 2011 – October 2013.	Head of Fund Treasury and Tax, Grantham, Mayo, Van Otterloo & Co. LLC (December 2006 – present).
Carly Cushman YOB: 1984	Treasurer, Chief Accounting Officer, and Chief Financial Officer	Chief Accounting Officer since June 2015; Treasurer and Chief Financial Officer since April 2014; Assistant Treasurer, October 2013 – April 2014.	Fund Administrator, Grantham, Mayo, Van Otterloo & Co. LLC (December 2009 – present); Senior Accountant, Renaissance HealthCare (February 2009 – December 2009); Auditor/Senior Auditor, Deloitte & Touche (September 2006 – February 2009).
John L. Nasrah YOB: 1977	Assistant Treasurer and Chief Tax Officer	Since November 2011.	Fund Administrator, Grantham, Mayo, Van Otterloo & Co. LLC (September 2004 – present).
Betty Maganzini YOB: 1972	Assistant Treasurer	Since October 2013.	Fund Administrator, Grantham, Mayo, Van Otterloo & Co. LLC (July 2010 – present); Assistant Treasurer (June 2009 – July 2010), Manager, Fund Administration and Regulatory Affairs (2006 – 2009), Hambrecht & Quist Capital Management LLC.
Mahmoodur Rahman YOB: 1967	Assistant Treasurer	Since November 2011.	Fund Administrator, Grantham, Mayo, Van Otterloo & Co. LLC (April 2007 – present).
Cathy Tao YOB: 1974	Assistant Treasurer	Since April 2015.	Fund Administrator, Grantham, Mayo, Van Otterloo & Co. LLC (October 2007 – present).
Brian Kadehjian YOB: 1974	Assistant Treasurer and Treasury Officer	Assistant Treasurer since February 2015; Treasury Officer since October 2013.	Fund Administrator, Grantham, Mayo, Van Otterloo & Co. LLC (April 2002 – present).
Douglas Y. Charton YOB: 1982	Chief Legal Officer, Vice President and Clerk	Since September 2015.	Legal Counsel, Grantham, Mayo, Van Otterloo & Co. LLC (July 2015 – present); Associate, K&L Gates LLP (September 2007 – July 2015).
Megan Bunting YOB: 1978	Vice President and Assistant Clerk	Since October 2013.	Legal Counsel, Grantham, Mayo, Van Otterloo & Co. LLC (September 2006 – present).
Kevin O’Brien YOB: 1985	Vice President and Assistant Clerk	Since March 2016.	Legal Counsel, Grantham, Mayo, Van Otterloo & Co. LLC (February 2015 – present); Associate, Dechert LLP (October 2010 – February 2015).

63

Officers — (Continued)
Name and Year of Birth	Position(s) Held with the Trust	Length of Time Served	Principal Occupation(s) During Past 5 Years*
Gregory L. Pottle YOB: 1971	Chief Compliance Officer, Vice President and Assistant Clerk	Chief Compliance Officer since May 2015; Vice President and Assistant Clerk since November 2011.	Chief Compliance Officer, Grantham, Mayo, Van Otterloo & Co. LLC (May 2015 – present); Legal Counsel, Grantham, Mayo, Van Otterloo & Co. LLC (March 2000 – May 2015).
Claire Wilkinson YOB: 1965	Anti-Money Laundering Officer	Since March 2016.	Compliance Associate, GMO UK Limited (April 2013 – present); General Counsel, MVision Private Equity Advisers Limited (November 2009 – January 2013).

^*  Each officer of the Trust may also serve as an officer and/or director of certain pooled investment vehicles of which GMO or an affiliate of GMO serves as the investment adviser. With the exception of Ms. Tao, each officer listed in the table above also serves as an officer of GMO Trust.

64

Item 2. Code of Ethics.

As of February 28, 2017, the registrant has adopted a Code of Ethics that applies to the Principal Executive Officer and Principal Financial Officer pursuant to the Sarbanes-Oxley Act of 2002 (the “Code of Ethics”). During the period ended February 28, 2017, there were no substantive amendments to a provision of the Code of Ethics nor were there any waivers granted from a provision of the Code of Ethics. A copy of the registrant’s Code of Ethics is filed with this Form N-CSR under item 12 (a).

Item 3. Audit Committee Financial Expert.

The registrant’s Board of Trustees has determined that the registrant does not have an “audit committee financial expert” (as such term has been defined in Form N-CSR) serving on its audit committee. The registrant’s Board believes that, although none of its members individually meets all required elements of the definition of an “audit committee financial expert”, the members of the registrant’s audit committee collectively possess the knowledge and experience necessary to execute all of the audit committee’s functions, duties and powers.

Item 4. Principal Accountant Fees and Services. *

(a) AUDIT FEES: The aggregate fees billed to the registrant for professional services rendered by its independent auditors, PricewaterhouseCoopers LLP for the audit of the registrant’s annual financial statements for 2017 and 2016 were $66,000 and $66,000, respectively.

(b) AUDIT-RELATED FEES: The aggregate fees billed to the registrant in 2017 and 2016 for engagements for audit-related services rendered by PricewaterhouseCoopers LLP that related directly to the operations and financial reporting of the Funds were $0 and $0, respectively. The aggregate fees billed in 2017 and 2016 to the registrant’s Investment Advisor, and any entity controlling, controlled, or under common control with the Advisor that provides ongoing services to the Funds (each, a “Service Affiliate”) for engagements for audit-related services rendered by PricewaterhouseCoopers LLP that related directly to the operations and financial reporting of the Funds were $514,334 and $504,899, respectively.

(c) TAX FEES: The aggregate fees billed to the registrant in 2017 and 2016 for professional services rendered by PricewaterhouseCoopers LLP for tax compliance, tax advice, and tax planning, including the preparation of Form 1120 RIC, Form 8613 and review of excise tax distribution calculations, were $43,460 and $51,050, respectively. The aggregate fees billed in 2017 and 2016 to the registrant’s Service Affiliates for engagements for tax services rendered by PricewaterhouseCoopers LLP that related directly to the operations and financial reporting of the Funds were $0 and $0, respectively.

(d) ALL OTHER FEES: No such fees were billed by PricewaterhouseCoopers LLP to the registrant or to the registrant’s Service Affiliates that related directly to the operations and financial reporting of the Funds in 2017 or 2016.

(e) (1) The Audit Committee has adopted an Audit and Non-Audit Services Pre-Approval Policy (the “Policy”), which sets forth the procedures and the conditions pursuant to which services to be performed by the independent auditor are to be preapproved. Under the Policy, the Audit Committee pre-approves, on an annual basis, the following services: (1) the engagement, scope and terms of the annual audit; (2) certain audit-related services; (3) certain tax services that the Committee believes would not impair, and are consistent with the SEC’s rules on auditor independence; and (4) certain permissible non-audit services that the Committee believes are routine and recurring services and that would not impair, and are consistent with the SEC’s rules on auditor independence, subject to certain limitations on the projected fees associated with each service. All other types of services not included on the schedule to the policy, or for which the projected fees exceed those provided in the schedule, require the specific pre-approval by the Audit Committee or the Chairperson of the Committee (if timing necessitates that preapproval is required before the Committee’s next regularly scheduled meeting) if they are to be provided by the independent auditor.

(e) (2) None.

(f) Not applicable.

(g) NON-AUDIT FEES: The aggregate fees billed by PricewaterhouseCoopers LLP in 2017 and 2016 for non-audit services rendered to the registrant and the registrant’s Service Affiliates were $592,794 and $590,949, respectively. For the fiscal period ended February 28, 2017, this amount reflects the amounts disclosed above in Item 4(b),(c),(d), plus $35,000 in fees billed to the Funds’ Service Affiliates for non-audit services that did not relate directly to the operations and financial reporting of the Funds. For the fiscal year ended February 29, 2016, this amount reflects the amounts disclosed above in Item 4(b),(c),(d), plus $35,000 in fees billed to the Funds’ Service Affiliates for non-audit services that did not relate directly to the operations and financial reporting of the Funds.

(h) The registrant’s Audit Committee has considered whether the provision of non-audit services by the registrant’s independent registered public accounting firm to the registrant’s Investment Advisor, and any entity controlling, controlled, or under common control with the Advisor that provided ongoing services to the registrant that were not pre-approved by the Committee (because such services did not relate directly to the operations and financial reporting of the registrant) was compatible with maintaining the independence of the independent registered public accounting firm.

* Includes information regarding all series of GMO Series Trust.

Item 5. Audit Committee of Listed Registrants.

Not applicable to this registrant.

Item 6. Schedule of Investments.

The complete schedule of investments for each series of the registrant is included as part of the annual reports to shareholders filed under Item 1 of this Form N-CSR.

Item 7. Disclosure of Proxy Voting Policies and Procedures for Closed-End Management Investment Companies.

Not applicable to this registrant.

Item 8. Portfolio Managers of Closed-End Management Investment Companies.

Not applicable to this registrant.

Item 9. Purchases of Equity Securities by Closed-End Management Investment Company and Affiliated Purchasers.

Not applicable to this registrant.

Item 10. Submission of Matters to a Vote of Security Holders.

There were no material changes to the procedures by which shareholders may recommend nominees to the registrant’s Board of Trustees.

Item 11. Controls and Procedures.

(a) The registrant’s Principal Executive Officer and Principal Financial Officer have concluded as of a date within 90 days of the filing of this report, based on their evaluation of the registrant’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) that the design and operation of such procedures are effective to provide reasonable assurance that information required to be disclosed by the registrant on Form N-CSR is recorded, processed, summarized, and reported within the time periods specified in the Commission’s rules and forms.

(b) There were no changes in the registrant’s internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) that occurred during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting.

Item 12. Exhibits.

(a)(1) Code of Ethics described in Item 2 is attached hereto as EX-99.CODEETH.

(a)(2) Certifications by the Principal Executive Officer and Principal Financial Officer of the registrant as required by Rule 30a-2(a) under the Investment Company Act of 1940 are attached hereto as EX-99.CERT.

(a)(3) Not applicable to this registrant.

(b) Certifications by the Principal Executive Officer and Principal Financial Officer of the registrant pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 and required by Rule 30a-2(b) under the Investment Company Act of 1940 are attached hereto as EX-99.906CERT.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant)	GMO Series Trust
By (Signature and Title):	/s/ Sheppard N. Burnett
	Sheppard N. Burnett, Chief Executive Officer
	Date: May 3, 2017

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title):	/s/ Sheppard N. Burnett
	Sheppard N. Burnett, Principal Executive Officer
	Date: May 3, 2017
By (Signature and Title):	/s/ Carly Cushman
	Carly Cushman, Principal Financial Officer
	Date: May 3, 2017

EX-99.CODEETH

Code of Ethics for Principal Executive Officer and Principal Accounting Officer January 31, 2017	GMO Series Trust

I. Covered Officers/Purpose of the Code

This code of ethics (the “Code”) for GMO Series Trust (the “Trust”) and each series thereof constituting a separate investment portfolio (the “Funds”) applies to the Trust’s Principal Executive Officer and Principal Accounting Officer (the “Covered Officers”). The Code is intended to promote:

• honest and ethical conduct, including the ethical handling of actual or apparent conflicts of interest between personal and professional relationships;

• full, fair, accurate, timely and understandable disclosure in reports and documents that a registrant files with, or submits to, the SEC and in other public communications made by the Trust;

• compliance with applicable laws and governmental rules and regulations;

• the prompt internal reporting of violations of the Code to an appropriate person or persons identified in the Code; and

• accountability for adherence to the Code.

Each Covered Officer should adhere to high standards of business ethics and should be sensitive to situations that may give rise to actual as well as apparent conflicts of interest.

II. Covered Officers Should Handle Ethically Actual and Apparent Conflicts of Interest

Overview. A “conflict of interest” occurs when a Covered Officer’s private interest interferes with the interests of, or that Officer’s service to, the Trust. For example, a conflict of interest would arise if a Covered Officer, or a member of his family, receives improper personal benefits as a result of that Officer’s position in the Trust.

Although typically not presenting an opportunity for improper personal benefit, conflicts arise from, or as a result of, the contractual relationship between the Trust and Grantham, Mayo, Van Otterloo & Co. LLC (“GMO”), the Trust’s investment adviser, of which the Covered Officers are also members, officers or employees. As a result, this Code recognizes that the Covered Officers will, in the normal course of their duties (whether formally for the Trust or GMO, or for both), be involved in establishing policies and implementing decisions which will have different effects on GMO and the Trust. The participation of the Covered Officers in such activities is inherent in the contractual relationship between the Trust and GMO and is consistent with the performance by the Covered Officers of their duties as officers of the Trust. In addition, it is recognized by the Trustees of the Trust (the “Trustees”) that the Covered Officers may also be officers or employees of one or more other investment companies covered by this or other Codes. These types of conflicts are addressed by the Investment Company Act, the Investment Advisers Act and other policies and procedures of the Trust.

Other conflicts of interest are covered by the Code, even if such conflicts of interest are not subject to provisions in the Investment Company Act and the Investment Advisers Act. In reading the following examples of conflicts of interest under the Code, Covered Officers should keep in mind that such a list cannot ever be exhaustive by covering every possible scenario. It follows that the overarching principle – that the personal interest of a Covered Officer should not be placed improperly before the interest of the Trust – should be the guiding principle in all circumstances.

Each Covered Officer must:

• not use personal influence or personal relationships improperly to influence investment decisions or financial reporting by the Trust whereby the Covered Officer would benefit personally to the detriment of the Trust;

• not cause the Trust to take action, or fail to take action, for the individual personal benefit of the Covered Officer rather than for the benefit of the Trust;

• not use material non-public knowledge of portfolio transactions made or contemplated for the Trust to profit personally or cause others to profit, by the market effect of such transactions;

• not retaliate against any employee or Covered Officer for reports of potential violations of law that are made in good faith.

There are some conflict of interest situations that should always be discussed with the Trust’s Chief Legal Officer if material. Examples of these include:

• any outside business activity other than with GMO and its affiliates that detracts from an individual’s ability to devote appropriate time and attention to his responsibilities with the Trust;

• service as a director on the board (or equivalent position) of any company;

• the receipt of any non-nominal gifts in excess of the amount stated in GMO’s Gift Policy;

• the receipt of any entertainment from any company with which the Trust has current or prospective business dealings unless such entertainment is business- related, reasonable in cost, appropriate as to time and place, and not so frequent as to raise any question of impropriety;

• any ownership interest in, or any consulting or employment relationship with, any of the Trust’s service providers, other than GMO and its affiliates;

• a direct or indirect financial interest in commissions, transaction charges or spreads paid by the Trust for effecting portfolio transactions or for selling or redeeming shares other than an interest arising from the Covered Officer’s employment, such as compensation or equity ownership.

III. Disclosure

• Each Covered Officer must be familiar with the disclosure requirements applicable to the Trust and the Funds’ disclosure controls and procedures;

• Each Covered Officer must not knowingly misrepresent, or cause others to misrepresent, facts about the Trust to others, whether within or outside the Trust, including to the Trustees and auditors, and to governmental regulators and self-regulatory organizations; and

• It is the responsibility of each Covered Officer to promote compliance with the standards and restrictions imposed by applicable, laws, rules and regulations.

2

IV. Reporting and Accountability

Each Covered Officer must:

• upon adoption of the Code (or thereafter as applicable, upon becoming a Covered Officer), affirm in writing to the Trust that the Covered Officer has received, read, and understands the Code (Exhibit A).

• annually thereafter affirm to the Trust that the Covered Officer has complied with the requirements of the Code by completing the Annual Holdings Report within GMO’s online Code of Ethics system.

• report at least annually affiliations and potential conflicts by completing the Annual Outside Business Activity Report within GMO’s online Code of Ethics system.

• notify the Trust’s Chief Legal Officer and the Chairman of the Trust’s Audit Committee promptly if Covered Officer knows of any violation of this Code. Failure to do so is itself a violation of this Code.

The Trust’s Chief Legal Officer is responsible for applying this Code to specific situations in which questions are presented under it and has the authority to interpret this Code in any particular situation. However, any approvals or waivers sought by any Covered Officer must be considered by the Trust’s Audit Committee.

The Trust will follow these procedures in investigating and enforcing this Code:

• the Trust’s Chief Legal Officer will take all appropriate action to investigate any violations and potential violations reported to him;

• if, after such investigation, the Trust’s Chief Legal Officer believes that no violation has occurred, the Chief Legal Officer is not required to take any further action; any matter the Trust’s Chief Legal Officer believes is or may be a violation will be reported to the Trust’s Audit Committee;

• if the Audit Committee determines that a violation has occurred, it will inform and make a recommendation to the Trustees, which will consider appropriate action which may include review of, and appropriate modifications to, applicable policies and procedures; notification to appropriate personnel of GMO or its board; or a recommendation to dismiss the Covered Officer as an officer of the Trust; and

• any changes to or waivers of this Code will, to the extent required, be disclosed as provided by SEC rules.

V. Other Policies and Procedures

The Trust’s Code of Ethics pursuant to Rule 17j-1 under the Investment Company Act, GMO’s Code of Ethics pursuant to Rule 204A-1 under the Investment Advisers Act, and GMO’s more detailed policies and procedures are separate requirements applying to the Covered Officers and others, and are not part of this Code. This Code does not, and is not intended to, repeat or replace these programs and procedures.

3

VI. Amendments

This Code may not be amended except in written form, which is specifically approved or ratified by a majority vote of the Trustees, including a majority of independent Trustees.

VII. Confidentiality

All reports and records prepared or maintained pursuant to this Code will be considered confidential and shall be maintained and protected accordingly. Except as otherwise required by law or this Code or in response to a request from a regulatory agency or self-regulatory organization, such matters shall not be disclosed to anyone other than the Audit Committee, the Trustees, their respective counsel, and GMO and its counsel.

VIII. Internal Use

The Code is intended solely for the internal use by the Trust and does not constitute an admission, by or on behalf of any Trust, as to any fact, circumstance, or legal conclusion and does not create any rights of third parties.

4

Exhibit A¹

GMO Series Trust Principal Officers Code Acknowledgement

Section IV of the GMO Series Trust Code of Ethics for Principal Executive Officer and Principal Financial Officer (the “Code”) requires that each Covered Officer, upon adoption of the Code, affirm in writing to the Trust that the Covered Officer has received, read, and understands the Code. By executing this, the undersigned makes such affirmation.

¹  As of November 29, 2016.

5

EX-99.CERT

EX-99.CERT

CERTIFICATION PURSUANT TO RULE 30(a)-2(a) UNDER THE 1940 ACT AND SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002:

I, Sheppard N. Burnett, Principal Executive Officer of the registrant, certify that:

1. I have reviewed this report on Form N-CSR of GMO Series Trust;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 3, 2017	/s/ Sheppard N. Burnett
	Sheppard N. Burnett, Principal Executive Officer

EX-99.CERT

CERTIFICATION PURSUANT TO RULE 30(a)-2(a) UNDER THE 1940 ACT AND SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002:

I, Carly Cushman, Principal Financial Officer of the registrant, certify that:

1. I have reviewed this report on Form N-CSR of GMO Series Trust;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

(a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report based on such evaluation; and

(d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

(b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 3, 2017	/s/ Carly Cushman
	Carly Cushman, Principal Financial Officer

EX-99.906CERT

EX-99.906 CERT

CERTIFICATION PURSUANT TO RULE 30(a)-2(b) UNDER THE 1940 ACT AND SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Sheppard N. Burnett, Principal Executive Officer of GMO Series Trust (the “Registrant”), certifies to the best of his knowledge that:

1. The Registrant’s periodic report on Form N-CSR for the period ended February 28, 2017 (the “Form N-CSR”) fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Form N-CSR fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

/s/ Sheppard N. Burnett

Sheppard N. Burnett

Principal Executive Officer

Date: May 3, 2017                    

A signed original of this written statement required by Section 906 of the Sarbanes-Oxley Act of 2002, or other document authenticating, acknowledging, or otherwise adopting the signature that appears in typed form within the electronic version of this written statement required by Section 906 has been provided to the Registrant and will be retained by the Registrant and furnished to the Securities and Exchange Commission (the “Commission”) or its staff upon request.

This certification is being furnished to the Commission solely pursuant to 18 U.S.C. § 1350 and is not being filed as part of the Form N-CSR with the Commission.

EX-99.906 CERT

CERTIFICATION PURSUANT TO RULE 30(a)-2(b) UNDER THE 1940 ACT AND SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

Carly Cushman, Principal Financial Officer of GMO Series Trust (the “Registrant”), certifies to the best of her knowledge that:

1. The Registrant’s periodic report on Form N-CSR for the period ended February 28, 2017 (the “Form N-CSR”) fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2. The information contained in the Form N-CSR fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

/s/ Carly Cushman

Carly Cushman

Principal Financial Officer

Date: May 3, 2017                    

A signed original of this written statement required by Section 906 of the Sarbanes-Oxley Act of 2002, or other document authenticating, acknowledging, or otherwise adopting the signature that appears in typed form within the electronic version of this written statement required by Section 906 has been provided to the Registrant and will be retained by the Registrant and furnished to the Securities and Exchange Commission (the “Commission”) or its staff upon request.

This certification is being furnished to the Commission solely pursuant to 18 U.S.C. § 1350 and is not being filed as part of the Form N-CSR with the Commission.