Prospectus

State Street ESG Liquid Reserves Fund

Institutional Class (ELFXX)    Administration Class (ESBXX)    Investment Class (ELGXX)    Investor Class (ENVXX)    Premier Class (ELRXX)    Opportunity Class (OPEXX)    

State Street Institutional Liquid Reserves Fund

Institutional Class (SSHXX)    Administration Class (SSYXX)    Investment Class (SSVXX)    Investor Class (SSZXX)    Premier Class (SSIXX)    Opportunity Class (OPIXX)    

State Street Institutional Treasury Money Market Fund

Institutional Class (SSJXX)    Administration Class (SSKXX)    Investment Class (TRVXX)    Investor Class (SSNXX)    Premier Class (TRIXX)    Opportunity Class (OPRXX)    

State Street Institutional Treasury Plus Money Market Fund

Institutional Class (SAJXX)    Administration Class (SSQXX)    Investment Class (TPVXX)    Investor Class (SAEXX)    Premier Class (TPIXX)    Opportunity Class (OPTXX)    

State Street Institutional U.S. Government Money Market Fund

Institutional Class (SAHXX)    Administration Class (SALXX)    Investment Class (GVVXX)    Investor Class (SAMXX)    Premier Class (GVMXX)    Opportunity Class (OPGXX)    

The U.S. Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

An investment in any of the Funds offered by this Prospectus is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Each Fund may offer multiple classes of shares. This Prospectus covers only the Institutional Class, Administration Class, Investment Class, Investor Class, Premier Class and Opportunity Class Shares of the applicable Funds.

State Street ESG Liquid Reserves Fund and State Street Institutional Liquid Reserves Fund are “floating net asset value” money market funds. The share price of these Funds will fluctuate.

None of State Street Corporation, State Street Bank and Trust Company, State Street Global Advisors, SSGA Funds Management, Inc. or their affiliates (“State Street Entities”) guarantee the value of your investment at $1.00 per share or any other target share price. Investors should have no expectation of capital support to the Funds from State Street Entities.

TABLE OF CONTENTS

Fund Summaries	1
State Street ESG Liquid Reserves Fund	1
State Street Institutional Liquid Reserves Fund	10
State Street Institutional Treasury Money Market Fund	17
State Street Institutional Treasury Plus Money Market Fund	22
State Street Institutional U.S. Government Money Market Fund	28
Additional Information About Investment Objectives, Principal Strategies and Risks	35
Additional Information About Non-Principal Investment Strategies and Risks	47
Portfolio Holdings Disclosure	49
Management and Organization	50
Shareholder Information	52
Dividends, Distributions and Tax Considerations	60
Financial Intermediary Arrangements	61
Financial Highlights	63

	Institutional		Administration		Investment		Investor		Premier		Opportunity
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None		None		None		None		None		None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None		None		None		None		None		None

	Institutional		Administration		Investment		Investor		Premier		Opportunity
Management Fee	0.05%		0.05%		0.05%		0.05%		0.05%		0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%		0.05%		0.10%		0.00%		0.00%		0.00%
Other Expenses1	0.13%		0.30%		0.35%		0.18%		0.10%		0.13%
Total Annual Fund Operating Expenses	0.18%		0.40%		0.50%		0.23%		0.15%		0.18%
Less Fee Waivers and/or Expense Reimbursements2	(0.03%)		(0.03%)		(0.03%)		(0.03%)		(0.03%)		(0.03%)
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements	0.15%		0.37%		0.47%		0.20%		0.12%		0.15%

1

Other Expenses for the Opportunity Class, Administration Class, and Investment Class shares are based on estimates for the current fiscal year.

2

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”) is contractually obligated, through April 30, 2023 (i) to waive up to the full amount of the advisory fee payable by the Fund, and/or (ii) to reimburse the Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.07% of average daily net assets on an annual basis (the “Total Annual Fund Operating Expense Waiver”). The Total Annual Fund Operating Expense Waiver may not be terminated prior to April 30, 2023 with respect to the Fund except with approval of the Fund's Board of Trustees. The Adviser and its affiliates, may voluntarily reduce all or a portion of their fees and/or reimburse expenses of the Fund or a share class to the extent necessary to maintain a certain minimum net yield, which may vary from time to time and from share class to share class within the Fund, in SSGA FM's sole discretion (any such waiver or reimbursement of expenses being referred to herein as a “Voluntary Reduction”), or a yield below a specified level, which may vary from time to time in the Adviser's sole discretion. The Fund has agreed, subject to certain limitations, to reimburse the Adviser and its affiliates for the full dollar amount of any Voluntary Reduction incurred beginning on May 1, 2020. During the fiscal year ended December 31, 2021, the Adviser and its affiliates did not waive fees or reimbursed expenses under the Voluntary Reduction.

1

Each of the Adviser and its affiliates may, in its sole discretion, irrevocably waive receipt of any or all reimbursement amounts due from the Fund. Any future reimbursement by the Fund of the Voluntary Reduction would increase the Fund's expenses and may reduce the Fund's yield during such period. There is no guarantee that the Voluntary Reduction will be in effect at any given time or that the Fund will be able to avoid a negative yield.

	1 year		3 years		5 years		10 years
Institutional	$15		$55		$98		$227
Administration	$38		$125		$221		$502
Investment	$48		$157		$277		$625
Investor	$20		$71		$126		$290
Premier	$12		$45		$82		$189
Opportunity	$15		$55		$98		$227

2

3

4

5

6

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.27% (Q2, 2020)
Lowest Quarterly Return: 0.01% (Q4, 2021) 

Average Annual Total Returns (for periods ended 12/31/21)

To obtain the Fund's current yield, please call (877) 521-4083.

7

Purchase and Sale of Fund Shares

Institutional Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Administration Class
To establish an account	$1,000
To add to an existing account	No minimum
Investment Class
To establish an account	$250
To add to an existing account	No minimum
Investor Class
To establish an account	$10,000,000
To add to an existing account	No minimum
Premier Class
To establish an account	$250,000,000
To add to an existing account	No minimum
Opportunity Class
To establish an account	$25,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

State Street Funds
430 W 7^th Street Suite 219737
Kansas City, MO 64105-1407

For wire transfer instructions, please call (866) 392-0869 between 7:00 a.m. and 5:00 p.m. Eastern time. Redemptions by telephone are permitted only if you previously have been authorized for these transactions.

If you wish to purchase or redeem Fund Shares through a broker, bank or other financial intermediary (“Financial Intermediary”), please contact that Financial Intermediary directly. Your Financial Intermediary may have different or additional requirements for opening an account and/or for the processing of purchase and redemption orders, or may be closed at times when the Fund is open.

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at [email protected] with questions.

Tax Information

For U.S. federal income tax purposes, the Fund's distributions are generally taxed as ordinary income unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

8

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase Fund Shares through a broker-dealer or other Financial Intermediary (such as a bank), the Adviser or its affiliates may pay the Financial Intermediary for certain activities related to the Fund, including educational training programs, conferences, the development of technology platforms and reporting systems, or other services related to the sale or promotion of the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your Financial Intermediary's website for more information.

9

	Institutional		Administration		Investment		Investor		Premier		Opportunity
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None		None		None		None		None		None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None		None		None		None		None		None

	Institutional		Administration		Investment		Investor		Premier		Opportunity
Management Fee	0.05%		0.05%		0.05%		0.05%		0.05%		0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%		0.05%		0.10%		0.00%		0.00%		0.00%
Other Expenses	0.10%		0.27%		0.32%		0.15%		0.07%		0.10%1
Total Annual Fund Operating Expenses2	0.15%		0.37%		0.47%		0.20%		0.12%		0.15%

1

Other Expenses for the Opportunity Class shares are based on estimates for the current fiscal year.

2

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”) and its affiliates, may voluntarily reduce all or a portion of their fees and/or reimburse expenses of the Fund or a share class to the extent necessary to maintain a certain minimum net yield, which may vary from time to time and from share class to share class within the Fund, in SSGA FM's sole discretion (any such waiver or reimbursement of expenses being referred to herein as a “Voluntary Reduction”), or a yield below a specified level, which may vary from time to time in the Adviser's sole discretion. The Fund has agreed, subject to certain limitations, to reimburse the Adviser and its affiliates for the full dollar amount of any Voluntary Reduction incurred beginning on May 1, 2020. During the fiscal year ended December 31, 2021, the Adviser and its affiliates waived fees and/or reimbursed expenses under the Voluntary Reduction. Each of the Adviser and its affiliates may, in its sole discretion, irrevocably waive receipt of any or all reimbursement amounts due from the Fund. Any future reimbursement by the Fund of the Voluntary Reduction would increase the Fund's expenses and may reduce the Fund's yield during such period. There is no guarantee that the Voluntary Reduction will be in effect at any given time or that the Fund will be able to avoid a negative yield.

	1 year		3 years		5 years		10 years
Institutional	$15		$48		$85		$192

10

	1 year		3 years		5 years		10 years
Administration	$38		$119		$208		$468
Investment	$48		$151		$263		$591
Investor	$20		$64		$113		$255
Premier	$12		$39		$68		$154
Opportunity	$15		$48		$85		$192

11

12

13

14

 

Average Annual Total Returns (for periods ended 12/31/21)

To obtain the Fund's current yield, please call (877) 521-4083.

15

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

State Street Funds
430 W 7^th Street Suite 219737
Kansas City, MO 64105-1407

For wire transfer instructions, please call (866) 392-0869 between 7:00 a.m. and 5:00 p.m. Eastern time. Redemptions by telephone are permitted only if you previously have been authorized for these transactions.

If you wish to purchase or redeem Fund Shares through a broker, bank or other financial intermediary (“Financial Intermediary”), please contact that Financial Intermediary directly. Your Financial Intermediary may have different or additional requirements for opening an account and/or for the processing of purchase and redemption orders, or may be closed at times when the Fund is open.

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at [email protected] with questions.

Tax Information

For U.S. federal income tax purposes, the Fund's distributions are generally taxed as ordinary income unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase Fund Shares through a broker-dealer or other Financial Intermediary (such as a bank), the Adviser or its affiliates may pay the Financial Intermediary for certain activities related to the Fund, including educational training programs, conferences, the development of technology platforms and reporting systems, or other services related to the sale or promotion of the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your Financial Intermediary's website for more information.

16

	Institutional		Administration		Investment		Investor		Premier		Opportunity
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None		None		None		None		None		None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None		None		None		None		None		None

	Institutional		Administration		Investment		Investor		Premier		Opportunity
Management Fee	0.05%		0.05%		0.05%		0.05%		0.05%		0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%		0.05%		0.10%		0.00%		0.00%		0.00%
Other Expenses	0.10%		0.27%		0.32%		0.15%		0.07%		0.10%1
Total Annual Fund Operating Expenses2	0.15%		0.37%		0.47%		0.20%		0.12%		0.15%

1

Other Expenses for the Opportunity Class shares are based on estimates for the current fiscal year.

2

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), and its affiliates, may voluntarily reduce all or a portion of their fees and/or reimburse expenses of the Fund or a share class to the extent necessary to maintain a certain minimum net yield, which may vary from time to time and from share class to share class within the Fund, in SSGA FM's sole discretion (any such waiver or reimbursement of expenses being referred to herein as a “Voluntary Reduction”), or a yield below a specified level, which may vary from time to time in the Adviser's sole discretion. The Fund has agreed, subject to certain limitations, to reimburse the Adviser and its affiliates for the full dollar amount of any Voluntary Reduction incurred beginning on May 1, 2020. During the fiscal year ended December 31, 2021, the Adviser and its affiliates waived fees and/or reimbursed expenses under the Voluntary Reduction. Each of the Adviser and its affiliates may, in its sole discretion, irrevocably waive receipt of any or all reimbursement amounts due from the Fund. Any future reimbursement by the Fund of the Voluntary Reduction would increase the Fund's expenses and may reduce the Fund's yield during such period. There is no guarantee that the Voluntary Reduction will be in effect at any given time or that the Fund will be able to avoid a negative yield.

	1 year		3 years		5 years		10 years
Institutional	$15		$48		$85		$192

17

	1 year		3 years		5 years		10 years
Administration	$38		$119		$208		$468
Investment	$48		$151		$263		$591
Investor	$20		$64		$113		$255
Premier	$12		$39		$68		$154
Opportunity	$15		$48		$85		$192

18

19

 

Average Annual Total Returns (for periods ended 12/31/21)

To obtain the Fund's current yield, please call (877) 521-4083.

20

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

State Street Funds
430 W 7^th Street Suite 219737
Kansas City, MO 64105-1407

For wire transfer instructions, please call (866) 392-0869 between 7:00 a.m. and 5:00 p.m. Eastern time. Redemptions by telephone are permitted only if you previously have been authorized for these transactions.

If you wish to purchase or redeem Fund Shares through a broker, bank or other financial intermediary (“Financial Intermediary”), please contact that Financial Intermediary directly. Your Financial Intermediary may have different or additional requirements for opening an account and/or for the processing of purchase and redemption orders, or may be closed at times when the Fund is open.

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at [email protected] with questions.

Tax Information

For U.S. federal income tax purposes, the Fund's distributions are expected to be taxed as ordinary income unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase Fund Shares through a broker-dealer or other Financial Intermediary (such as a bank), the Adviser or its affiliates may pay the Financial Intermediary for certain activities related to the Fund, including educational training programs, conferences, the development of technology platforms and reporting systems, or other services related to the sale or promotion of the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your Financial Intermediary's website for more information.

21

	Institutional		Administration		Investment		Investor		Premier		Opportunity
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None		None		None		None		None		None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None		None		None		None		None		None

	Institutional		Administration		Investment		Investor		Premier		Opportunity
Management Fee	0.05%		0.05%		0.05%		0.05%		0.05%		0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%		0.05%		0.10%		0.00%		0.00%		0.00%
Other Expenses	0.10%		0.27%		0.32%		0.15%		0.07%		0.10%1
Total Annual Fund Operating Expenses2	0.15%		0.37%		0.47%		0.20%		0.12%		0.15%

1

Other Expenses for the Opportunity Class shares are based on estimates for the current fiscal year.

2

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), and its affiliates, may voluntarily reduce all or a portion of their fees and/or reimburse expenses of the Fund or a share class to the extent necessary to maintain a certain minimum net yield, which may vary from time to time and from share class to share class within the Fund, in SSGA FM's sole discretion (any such waiver or reimbursement of expenses being referred to herein as a “Voluntary Reduction”), or a yield below a specified level, which may vary from time to time in the Adviser's sole discretion. The Fund has agreed, subject to certain limitations, to reimburse the Adviser and its affiliates for the full dollar amount of any Voluntary Reduction incurred beginning on May 1, 2020. During the fiscal year ended December 31, 2021, the Adviser and its affiliates waived fees and/or reimbursed expenses under the Voluntary Reduction. Each of the Adviser and its affiliates may, in its sole discretion, irrevocably waive receipt of any or all reimbursement amounts due from the Fund. Any future reimbursement by the Fund of the Voluntary Reduction would increase the Fund's expenses and may reduce the Fund's yield during such period. There is no guarantee that the Voluntary Reduction will be in effect at any given time or that the Fund will be able to avoid a negative yield.

	1 year		3 years		5 years		10 years
Institutional	$15		$48		$85		$192

22

	1 year		3 years		5 years		10 years
Administration	$38		$119		$208		$468
Investment	$48		$151		$263		$591
Investor	$20		$64		$113		$255
Premier	$12		$39		$68		$154
Opportunity	$15		$48		$85		$192

23

24

25

 

Average Annual Total Returns (for periods ended 12/31/21)

To obtain the Fund's current yield, please call (877) 521-4083.

26

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

State Street Funds
430 W 7^th Street Suite 219737
Kansas City, MO 64105-1407

For wire transfer instructions, please call (866) 392-0869 between 7:00 a.m. and 5:00 p.m. Eastern time. Redemptions by telephone are permitted only if you previously have been authorized for these transactions.

If you wish to purchase or redeem Fund Shares through a broker, bank or other financial intermediary (“Financial Intermediary”), please contact that Financial Intermediary directly. Your Financial Intermediary may have different or additional requirements for opening an account and/or for the processing of purchase and redemption orders, or may be closed at times when the Fund is open.

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at [email protected] with questions.

Tax Information

For U.S. federal income tax purposes, the Fund's distributions are expected to be taxed as ordinary income unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase Fund Shares through a broker-dealer or other Financial Intermediary (such as a bank), the Adviser or its affiliates may pay the Financial Intermediary for certain activities related to the Fund, including educational training programs, conferences, the development of technology platforms and reporting systems, or other services related to the sale or promotion of the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your Financial Intermediary's website for more information.

27

	Institutional		Administration		Investment		Investor		Premier		Opportunity
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None		None		None		None		None		None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price)	None		None		None		None		None		None

	Institutional		Administration		Investment		Investor		Premier		Opportunity
Management Fee	0.05%		0.05%		0.05%		0.05%		0.05%		0.05%
Distribution and/or Shareholder Service (12b-1) Fees	0.00%		0.05%		0.10%		0.00%		0.00%		0.00%
Other Expenses	0.10%		0.27%		0.32%		0.15%		0.07%		0.10%1
Total Annual Fund Operating Expenses2	0.15%		0.37%		0.47%		0.20%		0.12%		0.15%

1

Other Expenses for the Opportunity Class shares are based on estimates for the current fiscal year.

2

The Fund's investment adviser, SSGA Funds Management, Inc. (the “Adviser” or “SSGA FM”), and its affiliates, may voluntarily reduce all or a portion of their fees and/or reimburse expenses of the Fund or a share class to the extent necessary to maintain a certain minimum net yield, which may vary from time to time and from share class to share class within the Fund, in SSGA FM's sole discretion (any such waiver or reimbursement of expenses being referred to herein as a “Voluntary Reduction”), or a yield below a specified level, which may vary from time to time in the Adviser's sole discretion. The Fund has agreed, subject to certain limitations, to reimburse the Adviser and its affiliates for the full dollar amount of any Voluntary Reduction incurred beginning on May 1, 2020. During the fiscal year ended December 31, 2021, the Adviser and its affiliates waived fees and/or reimbursed expenses under the Voluntary Reduction. Each of the Adviser and its affiliates may, in its sole discretion, irrevocably waive receipt of any or all reimbursement amounts due from the Fund. Any future reimbursement by the Fund of the Voluntary Reduction would increase the Fund's expenses and may reduce the Fund's yield during such period. There is no guarantee that the Voluntary Reduction will be in effect at any given time or that the Fund will be able to avoid a negative yield.

28

	1 year		3 years		5 years		10 years
Institutional	$15		$48		$85		$192
Administration	$38		$119		$208		$468
Investment	$48		$151		$263		$591
Investor	$20		$64		$113		$255
Premier	$12		$39		$68		$154
Opportunity	$15		$48		$85		$192

29

30

31

Annual Total Returns (years ended 12/31)

Highest Quarterly Return: 0.58% (Q2, 2019)
Lowest Quarterly Return: 0.00% (Q3, 2013) 

Average Annual Total Returns (for periods ended 12/31/21)

To obtain the Fund's current yield, please call (877) 521-4083.

32

Purchase and Sale of Fund Shares

Institutional Class
To establish an account	$25,000,000
To add to an existing account	No minimum
Administration Class
To establish an account	$1,000
To add to an existing account	No minimum
Investment Class
To establish an account	$250
To add to an existing account	No minimum
Investor Class
To establish an account	$10,000,000
To add to an existing account	No minimum
Premier Class
To establish an account	$250,000,000
To add to an existing account	No minimum
Opportunity Class
To establish an account	$25,000,000
To add to an existing account	No minimum

You may purchase or redeem Fund Shares on any day the Fund is open for business.

You may purchase or redeem Fund Shares by written request or wire transfer. Written requests should be sent to:

State Street Funds
P.O. Box 219737
Kansas City, MO 64121-9737

State Street Funds
430 W 7^th Street Suite 219737
Kansas City, MO 64105-1407

For wire transfer instructions, please call (866) 392-0869 between 7:00 a.m. and 5:00 p.m. Eastern time. Redemptions by telephone are permitted only if you previously have been authorized for these transactions.

If you wish to purchase or redeem Fund Shares through a broker, bank or other financial intermediary (“Financial Intermediary”), please contact that Financial Intermediary directly. Your Financial Intermediary may have different or additional requirements for opening an account and/or for the processing of purchase and redemption orders, or may be closed at times when the Fund is open.

Financial Intermediaries may contact DST Asset Manager Solutions, Inc. at (877) 332-6207 or via email at [email protected] with questions.

Tax Information

For U.S. federal income tax purposes, the Fund's distributions are expected to be taxed as ordinary income unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account. Any withdrawals made from such tax-advantaged arrangement may be taxable to you.

33

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase Fund Shares through a broker-dealer or other Financial Intermediary (such as a bank), the Adviser or its affiliates may pay the Financial Intermediary for certain activities related to the Fund, including educational training programs, conferences, the development of technology platforms and reporting systems, or other services related to the sale or promotion of the Fund. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your Financial Intermediary's website for more information.

34

Additional Information About Investment Objectives, Principal Strategies and Risks

Investment Objective

The investment objective of each of the ESG Liquid Reserves Fund, ILR Fund, U.S. Government Fund, the Treasury Fund and the Treasury Plus Fund, as stated in each Fund's Summary, may be changed without shareholder approval.

ESG Liquid Reserves Fund

Principal Investment Strategies

The ESG Liquid Reserves Fund follows a disciplined investment process in which the Adviser bases its decisions on the relative attractiveness of different money market instruments while considering ESG criteria at the time of purchase. Among other things, the Adviser conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team.

The Fund invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. In the Adviser's opinion, the attractiveness of an instrument may vary depending on, among other things, the general level of interest rates and imbalances of supply and demand in the market.

Although the Fund is a money market fund, the net asset value (“NAV”) of the Fund's Shares “floats,” fluctuating with changes in the values of the Fund's portfolio securities. The Fund typically accepts purchase and redemption orders multiple times per day, and calculates its NAV at each such time.

The Adviser intends to consider ESG criteria at the time of purchase by using an ESG-related metric for each Fund investment. For most Fund investments, the Adviser uses a proprietary scoring system developed by SSGA that assigns an ESG rating, in the form of a “Responsibility” or “R-Factor^TM” score, to the issuer. The amount of the Fund's investments assigned an R-Factor^TM score will vary from time to time and can change significantly. The R-Factor^TM score measures the performance of a company's business operations and governance as related to financially material ESG challenges facing the issuer's industry. For example, for companies in the asset management industry, the R‑ FactorTM score currently uses metrics based on selling practices and product labeling, employee engagement / diversity and inclusion, product design and lifecycle management, business ethics, and systemic risk management. The R-Factor^TM score for each applicable issuer draws on a number of data sources, including third-party data providers, that provide metrics on a variety of ESG topics.

The R-Factor^TM scoring process comprises two underlying components. The first component is based on the framework published by the Sustainability Accounting Standards Board (“SASB”), which is used for all ESG aspects of the score other than those relating to corporate governance issues. The SASB framework attempts to identify ESG risks that are financially material to the issuer based on its industry classification. This component of the R-Factor^TM score is determined using only those metrics from the data sources that specifically address ESG risks identified by the SASB framework as being financially material to the issuer based on its industry classification.

The second component of the score is generated using region-specific corporate governance codes developed by investors or regulators. The governance codes describe minimum corporate governance expectations of a particular region and typically address topics such as shareholder rights, board independence and executive compensation. The R-Factor^TM scoring process uses data provided by a corporate governance data and analytics provider to assign a governance score to issuers according to these governance codes.

For an issuer that receives an R-Factor^TM score, the Fund generally will not take into account the practices or the record of the issuer in respect of ESG factors other than those (i) identified as being financially material to the issuer based on its industry classification under the SASB framework or (ii) applicable to the issuer under local governance codes. Not all criteria are assigned equal weight in constructing an R-Factor^TM score.

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R-Factor^TM scores are not used for investments in U.S. government securities, securities of governments other than the U.S. government, or securities of issuers for which ESG data sufficient to generate an R-Factor^TM score is not available. In the case of issuers for which R-Factor^TM scores are not used, security selection is based on the Adviser's fundamental security selection process, which may include the application of alternative ESG ratings from a data source to determine whether the issuer of a security meets a particular ESG criteria set by the Adviser.

In making investment decisions, the Adviser will normally consider ESG factors at the time of investment. Once a security is purchased by the Fund, the Adviser will periodically review an issuer's ESG score to determine how it compares to the Fund's ESG criteria and affects the Fund's overall ESG orientation, but the Adviser typically will not sell a security based solely on a change in the Adviser's ESG evaluation of an issuer. When determining whether to sell a security, the Adviser considers, among other things, current and anticipated changes in interest rates, current valuation relative to alternatives in the market, general market conditions and any other factors deemed relevant by the Adviser.

The Adviser will select securities for investment by the Fund based on its consideration of fundamental and technical factors relating to the investment, as well as in some cases seeking to increase R-Factor^TM scoring of the overall investment portfolio. The portfolio construction process begins with an analysis of fundamental factors relating to a potential investment, after which the Adviser conducts its ESG analysis, as described above. Final investment decisions are made by the portfolio managers typically on the basis of market conditions as well as technical and ESG considerations with respect to both specific instruments and the overall composition of the portfolio. The Adviser's ESG analysis is an integral component of portfolio construction. An issuer in which the Fund invests may rank higher or lower across ESG factors or in any one factor as compared with other issuers in which the Fund invests or might invest. For example, it is possible that the Adviser might select for investment the securities of an issuer with a lower R-Factor^TM score than another on the basis of the relative yield of that issuer's securities. Conversely, it is possible that the Adviser might select for investment the securities of an issuer with a higher R-Factor^TM score and lower yield than another to achieve a higher overall R-Factor^TM score for the investment portfolio. The Fund does not expect typically to invest in securities of issuers that do not achieve a minimum R-Factor^TM threshold score set by the Adviser from time to time (except that certain issuers, as noted above, do not receive R-Factor^TM scores). There may be certain investments with desirable investment attributes that the Adviser will not consider for investment by the Fund because they do not meet that threshold, and the Fund might achieve less favorable investment results than a comparable fund that is not so limited.

The Fund attempts to meet its investment objective by investing in a broad range of money market instruments. These may include, among other things: U.S. government securities, including U.S. Treasury bills, notes and bonds and other securities issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies or instrumentalities; certificates of deposits and time deposits of U.S. and foreign banks (including European Certificates of Deposit (“ECDs”), European Time Deposits (“ETDs”) and Yankee Certificates of Deposit (“YCDs”)), commercial paper and other high quality obligations of U.S. or foreign companies, including “green” bonds; secured securities such as asset-backed commercial paper; and repurchase agreements. These instruments may bear fixed, variable or floating rates of interest or may be zero-coupon securities. The Fund also may invest in shares of money market funds, including funds advised by the Adviser. Under normal market conditions, the Fund intends to invest more than 25% of its total assets in bank obligations. A substantial portion of the Fund may be invested in securities that are issued or traded pursuant to exemptions from registration under the federal securities laws.

ECDs are U.S. dollar-denominated certificates of deposit issued by a bank outside of the United States. ETDs are U.S. dollar-denominated deposits in foreign branches of U.S. banks and foreign banks. YCDs are U.S. dollar-denominated certificates of deposit issued by U.S. branches of foreign banks. These instruments have different risks than those associated with the obligations of U.S. banks operating in the United States.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the ESG Liquid Reserves Portfolio, a separate series of State Street Master Funds (the “Portfolio”), which has substantially identical investment policies to the Fund. When a Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Additional Information Regarding SASB. SASB is a non-profit organization that develops and maintains reporting standards intended to enable businesses around the world to identify, manage and communicate financially material sustainability information. SASB's framework consists of five broad sustainability dimensions or categories, including: environment, social capital, human capital, business model and innovation, and leadership and governance. The R-Factor^TM score

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only takes into account data relevant to each category when it is believed to be financially material to a company's industry. Each sustainability dimension or category consists of numerous sub-topics, including, but not limited to, air quality, energy management, human rights and community relations, customer welfare, labor practices, impact of climate change, and business ethics.

ILR Fund

Principal Investment Strategies

The ILR Fund follows a disciplined investment process in which SSGA FM bases its decisions on the relative attractiveness of different money market instruments. In the Adviser's opinion, the attractiveness of an instrument may vary depending on the general level of interest rates, as well as imbalances of supply and demand in the market. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity.

Although the Fund is a money market fund, the net asset value (“NAV”) of the Fund's Shares “floats,” fluctuating with changes in the values of the Fund's portfolio securities. The Fund typically accepts purchase and redemption orders multiple times per day, and calculates its NAV at each such time.

The Fund attempts to meet its investment objective by investing in a broad range of money market instruments. These may include, among other things: U.S. government securities, including U.S. Treasury bills, notes and bonds and other securities issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies or instrumentalities; certificates of deposits and time deposits of U.S. and foreign banks (including ECDs, ETDs and YCDs (as defined below), commercial paper and other high quality obligations of U.S. or foreign companies; asset-backed securities, including asset-backed commercial paper; mortgage-related securities, including non-governmental mortgage-related securities; and repurchase agreements. These instruments may bear fixed, variable or floating rates of interest or may be zero-coupon securities. The Fund also may invest in shares of other money market funds, including funds advised by the Adviser. Under normal market conditions, the Fund intends to invest more than 25% of its total assets in bank obligations. A substantial portion of the Fund may be invested in securities that are issued or traded pursuant to exemptions from registration under the federal securities laws.

European Certificates of Deposit (“ECDs”) are U.S. dollar-denominated certificates of deposit issued by a bank outside of the United States. European Time Deposits (“ETDs”) are U.S. dollar-denominated deposits in foreign branches of U.S. banks and foreign banks. Yankee Certificates of Deposit (“YCDs”) are U.S. dollar-denominated certificates of deposit issued by U.S. branches of foreign banks. These instruments have different risks than those associated with the obligations of U.S. banks operating in the United States.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Money Market Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Treasury Fund

Principal Investment Strategies

The Treasury Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government). The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

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The Fund invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Fund to invest only in short-term securities (generally, securities that have remaining maturities of 397 calendar days or less, with the exception of certain floating rate securities that may have final maturities longer than 397 days but use maturity shortening provisions to meet the 397 day requirement, and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Treasury Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Treasury Plus Fund

Principal Investment Strategies

The Treasury Plus Fund is a government money market fund and attempts to meet its investment objective by investing only in U.S. Treasury bills, notes and bonds (which are direct obligations of the U.S. government) and repurchase agreements collateralized by these obligations. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

The Fund invests in accordance with regulatory requirements applicable to money market funds, which require, among other things, the Fund to invest only in short-term securities (generally, securities that have remaining maturities of 397 calendar days or less, with the exception of certain floating rate securities that may have final maturities longer than 397 days but use maturity shortening provisions to meet the 397 day requirement, and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Treasury Plus Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

U.S. Government Fund

Principal Investment Strategies

The U.S. Government Fund is a government money market fund and invests only in obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, as well as repurchase agreements secured by such instruments. The Fund will provide shareholders with at least 60 days' prior notice of any change in this investment policy. The Fund may hold a portion of its assets in cash pending investment, to satisfy redemption requests or to meet the Fund's other cash management needs.

The Fund follows a disciplined investment process that attempts to provide stability of principal, liquidity and current income, by investing in U.S. government securities. Among other things, SSGA FM conducts its own credit analyses of potential investments and portfolio holdings, and relies substantially on a dedicated short-term credit research team. The Fund invests in accordance with regulatory requirements applicable to money market funds. Regulations require, among other things, a money market fund to invest only in short-term, high quality debt obligations (generally, securities that have remaining maturities of 397 calendar days or less, with the exception of certain floating rate securities that may have final maturities longer than 397 days but use maturity shortening provisions to meet the 397 day requirement, and that the Fund believes present minimal credit risk), to maintain a maximum dollar-weighted average maturity and dollar-weighted average life of sixty (60) days or less and 120 days or less, respectively, and to meet requirements as to portfolio diversification and liquidity. All securities held by the Fund are U.S. dollar-denominated, and they may have fixed, variable or floating interest rates.

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The Fund attempts to meet its investment objective by investing in:

•	Obligations issued or guaranteed as to principal and/or interest, as applicable, by the U.S. government or its agencies and instrumentalities, such as U.S. Treasury securities and securities issued by the Government National Mortgage Association (“GNMA”), which are backed by the full faith and credit of the United States;
•	Obligations issued or guaranteed by the Federal Home Loan Mortgage Corporation, the Federal National Mortgage Association, and U.S. government-sponsored entities such as the Federal Home Loan Bank, and the Federal Farm Credit Banks Funding Corporation, which are not backed by the full faith and credit of the United States; and
•	Repurchase agreements collateralized by U.S. government securities.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the U.S. Government Portfolio, which has substantially identical investment policies to the Fund. When the Fund invests in this “master-feeder” structure, the Fund's only investments are shares of the Portfolio, and it participates in the investment returns achieved by the Portfolio. Descriptions in this section of the investment activities of the “Fund” also generally describe the expected investment activities of the Portfolio.

Additional Information About Risks

The Funds are subject to the following principal risks. The risks are described in alphabetical order and not in the order of importance or potential exposure. Each principal risk without a parenthetical indicating a single Fund's name is applicable to each Fund.

Banking Companies Risk (principal risk for the ESG Liquid Reserves Fund and ILR Fund). The performance of bank stocks may be affected by extensive governmental regulation, which may limit both the amounts and types of loans and other financial commitments they can make, and the interest rates and fees they can charge and the amount of capital they must maintain. Profitability is largely dependent on the availability and cost of capital funds, and can fluctuate significantly when interest rates change. Credit losses resulting from financial difficulties of borrowers can negatively impact the banking companies. Banks may also be subject to severe price competition. Competition among banking companies is high and failure to maintain or increase market share may result in lost market value.

Call/Prepayment Risk (principal risk for the ESG Liquid Reserves Fund and ILR Fund). Call/prepayment risk is the risk that an issuer will exercise its right to pay principal on an obligation held by a Fund earlier than expected or required. This may occur, for example, when there is a decline in interest rates, and an issuer of bonds or preferred stock redeems the bonds or stock in order to replace them with obligations on which it is required to pay a lower interest or dividend rate. It may also occur when there is an unanticipated increase in the rate at which mortgages or other receivables underlying mortgage- or asset-backed securities held by a Fund are prepaid. In any such case, a Fund may be forced to invest the prepaid amounts in lower-yielding investments, resulting in a decline in the Fund's income.

Counterparty Risk (principal risk for the ESG Liquid Reserves Fund, ILR Fund, U.S. Government Fund and Treasury Plus Fund). A Fund will be subject to credit risk with respect to the counterparties with which a Fund enters into repurchase agreements and other transactions. If a counterparty fails to meet its contractual obligations, a Fund may be unable to terminate the transaction, and it may be delayed or prevented from realizing on any collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

Credit Risk (principal risk for the ESG Liquid Reserves Fund, ILR Fund, U.S. Government Fund and Treasury Plus Fund). Credit risk is the risk that an issuer, guarantor or liquidity provider of a fixed-income security held by a Fund may be unable or unwilling, or may be perceived (whether by market participants, ratings agencies, pricing services or otherwise) as unable or unwilling, to make timely principal and/or interest payments, or to otherwise honor its obligations. It includes the risk that the security will be downgraded by a credit rating agency; generally, lower credit quality issuers present higher credit risks. An actual or perceived decline in creditworthiness of an issuer of a fixed-income security held by a Fund may result in a decrease in the value of the security. It is possible that the ability of an issuer to meet its obligations will decline substantially during the period when a Fund owns securities of the issuer or that the issuer will default on its obligations or that the obligations of the issuer will be limited or restructured.

The credit rating assigned to any particular investment does not necessarily reflect the issuer's current financial condition and does not reflect an assessment of an investment's volatility or liquidity. Securities rated in the lowest category of investment-grade are considered to have speculative characteristics. If a security held by a Fund loses its rating or its

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rating is downgraded, the Fund may nonetheless continue to hold the security in the discretion of the Adviser. In the case of asset-backed or mortgage-related securities, changes in the actual or perceived ability of the obligors on the underlying assets or mortgages to make payments of interest and/or principal may affect the values of those securities.

Debt Securities Risk. The values of debt securities may increase or decrease as a result of the following: market fluctuations, changes in interest rates, actual or perceived inability or unwillingness of issuers, guarantors or liquidity providers to make scheduled principal or interest payments or illiquidity in debt securities markets; the risk of low rates of return due to reinvestment of securities during periods of falling interest rates or repayment by issuers with higher coupon or interest rates; and/or the risk of low income due to falling interest rates. To the extent that interest rates rise, certain underlying obligations may be paid off substantially slower than originally anticipated and the value of those securities may fall sharply. A rising interest rate environment may cause the value of a Fund's fixed income securities to decrease, an adverse impact on the liquidity of a Fund's fixed income securities, and increased volatility of the fixed income markets. The current low interest rate environment heightens the risks associated with rising interest rates. During periods when interest rates are at low levels, a Fund's yield can be low, and a Fund may have a negative yield (i.e., it may lose money on an operating basis). If the principal on a debt obligation is prepaid before expected, the prepayments of principal may have to be reinvested in obligations paying interest at lower rates. During periods of falling interest rates, the income received by a Fund may decline. Changes in interest rates will likely have a greater effect on the values of debt securities of longer durations. Returns on investments in debt securities could trail the returns on other investment options, including investments in equity securities.

ESG Investing Risk (principal risk for the ESG Liquid Reserves Fund). The Fund's incorporation of environmental, social and/or governance considerations in its investment process may cause it to make different investments than funds that have a similar investment universe and/or investment style but that do not incorporate such considerations in their investment strategy or processes. In applying ESG criteria to its investment decisions, the Fund may forgo higher yielding investments that it would invest in absent the application of its ESG investing criteria. The Fund's investment process may affect the Fund's exposure to certain investments, which may impact the Fund's relative investment performance depending on whether such investments are in or out of favor with the market. In addition, the Fund's investments in certain companies may be susceptible to various factors that may impact their businesses or operations, including costs associated with government budgetary constraints that impact publicly funded projects and clean energy initiatives, the effects of general economic conditions throughout the world, increased competition from other providers of services, unfavorable tax laws or accounting policies and high leverage. The Fund's portfolio managers rely on available information to assist in the ESG evaluation process, and the process employed for the Fund may differ from processes employed for other funds. The Fund will seek to identify companies that it believes meet its ESG criteria based on the data provided by third parties. The data provided by third parties may be incomplete, inaccurate or unavailable, which could cause the Adviser to incorrectly assess a company's ESG practices. The Fund may invest in companies that do not reflect the beliefs and values of any particular investor.

Due to constraints imposed by regulations applicable to money market funds or other considerations relating to credit quality, liquidity or yield, the Fund may be unable to successfully implement its ESG investment strategy. In addition, the Adviser generally will not sell a security as a result of a decline in an issuer's ESG rating, but will attempt to maintain a high R-Factor^TM score for the Fund's portfolio overall. As a result, if the R-Factor^TM score of a current Fund holding deteriorates, the Fund's new investment opportunities may be limited, since the Fund may be unable to invest in securities that are relatively lower-scoring.

Extension Risk (principal risk for the ESG Liquid Reserves Fund and ILR Fund). During periods of rising interest rates, the average life of certain types of securities may be extended because of slower-than-expected principal payments. This may increase the period of time during which an investment earns a below-market interest rate, increase the security's duration and reduce the value of the security. Extension risk may be heightened during periods of adverse economic conditions generally, as payment rates decline due to higher unemployment levels and other factors.

Financial Institutions Risk (principal risk for the ESG Liquid Reserves Fund and ILR Fund). Some instruments are issued or guaranteed by financial institutions, such as banks and brokers, or are collateralized by securities issued or guaranteed by financial institutions. Changes in the creditworthiness of any of these institutions may adversely affect the values of instruments of issuers in financial industries. Financial institutions may be particularly sensitive to certain economic factors such as interest rate changes, adverse developments in the real estate market, fiscal and monetary policy and general economic cycles. Adverse developments in banking and other financial industries may cause a Fund to underperform relative to other funds that invest more broadly across different industries or have a smaller exposure to

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financial institutions. Changes in governmental regulation and oversight of financial institutions may have an adverse effect on the financial condition or the earnings or operations of a financial institution and on the types and amounts of businesses in which a financial institution may engage. An investor may be delayed or prevented from exercising certain remedies against a financial institution. The amount of a Fund's assets that may be invested in any financial institution, or financial institutions generally, may be limited by applicable law.

Income Risk (principal risk for the ESG Liquid Reserves Fund, ILR Fund and U.S. Government Fund). A Fund's income may decline due to falling interest rates or other factors. Issuers of securities held by a Fund may call or redeem the securities during periods of falling interest rates, and the Fund would likely be required to reinvest in securities paying lower interest rates. If an obligation held by a Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates. A reduction in the income earned by a Fund may limit the Fund's ability to achieve its objective.

Interest Rate Risk. Interest rate risk is the risk that the securities held by a Fund will decline in value because of increases in market interest rates. Duration is a measure used to determine the sensitivity of a security's price to changes in interest rates. Debt securities with longer durations tend to be more sensitive to changes in interest rates, usually making them more volatile than debt securities with shorter durations. For example, the value of a security with a duration of five years would be expected to decrease by 5% for every 1% increase in interest rates. Falling interest rates also create the potential for a decline in a Fund's income and yield. Interest-only and principal-only securities are especially sensitive to interest rate changes, which can affect not only their prices but can also change the income flows and repayment assumptions about those investments. Variable and floating rate securities also generally increase or decrease in value in response to changes in interest rates, although generally to a lesser degree than fixed-rate securities. A substantial increase in interest rates may also have an adverse impact on the liquidity of a security, especially those with longer durations. Changes in governmental policy, including changes in central bank monetary policy, could cause interest rates to rise rapidly, or cause investors to expect a rapid rise in interest rates. This could lead to heightened levels of interest rate, volatility and liquidity risks for the fixed income markets generally and could have a substantial and immediate effect on the values of a Fund's investments.

Large Shareholder Risk. To the extent a large proportion of the interests of a Portfolio are highly concentrated or held by a small number of investors (or a single investor), including funds or accounts over which the Adviser has investment discretion, a Portfolio is subject to the risk that these investors will purchase or redeem Portfolio interests in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. These transactions could adversely affect the ability of a Portfolio to conduct its investment program. For example, they could require a Portfolio to sell portfolio securities or purchase portfolio securities unexpectedly and incur substantial transaction costs and/or accelerate the realization of taxable income and/or gains to investors, or a Portfolio may be required to sell its more liquid portfolio investments to meet a large redemption, in which case a Portfolio's remaining assets may be less liquid, more volatile, and more difficult to price. A Portfolio may hold a relatively large proportion of its assets in cash in anticipation of large redemptions, diluting its investment returns.

Liquidity Risk (principal risk for the ESG Liquid Reserves Fund and ILR Fund). Liquidity risk is the risk that a Fund may not be able to dispose of investments readily at a favorable time or prices (or at all) or at prices approximating those at which a Fund currently values them. For example, certain investments may be subject to restrictions on resale, may trade in the over-the-counter market or in limited volume, or may not have an active trading market. Illiquid investments may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. It may be difficult for a Fund to value illiquid investments accurately. The market for certain investments may become illiquid under adverse market or economic conditions independent of any specific adverse changes in the conditions of a particular issuer. Disposal of illiquid investments may entail registration expenses and other transaction costs that are higher than those for liquid investments. A Fund may seek to borrow money to meet its obligations (including among other things redemption obligations) if it is unable to dispose of illiquid investments, resulting in borrowing expenses and possible leveraging of the Fund. In some cases, due to unanticipated levels of illiquidity a Fund may choose to meet its redemption obligations wholly or in part by distributions of assets in-kind.

Low Short-Term Interest Rate Risk. During market conditions in which short-term interest rates are at low levels a Fund's yield can be very low. During these conditions, it is possible that a Fund will generate an insufficient amount of income to pay its expenses, and that it will not be able to pay a daily dividend and may have a negative yield (i.e., it may lose money on an operating basis). It is possible that a Fund would, during these conditions, maintain a substantial portion of its assets in cash, on which it may earn little, if any, income.

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Market Disruption and Geopolitical Risk. A Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. War, terrorism, 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, pandemics and epidemics, and systemic market dislocations may be highly disruptive to economies and markets. Those events, as well as other changes in foreign and domestic economic and political conditions, also could adversely affect individual issuers or related groups of issuers, securities markets, interest rates, credit ratings, inflation, investor sentiment, and other factors affecting the value of a Fund's investments. Given the increasing interdependence among global economies and markets, conditions in one country, market, or region might adversely affect markets, issuers, and/or foreign exchange rates in other countries, including the U.S. Any partial or complete dissolution of the Economic and Monetary Union of the European Union, or any increased uncertainty as to its status, could have significant adverse effects on currency and financial markets, and on the values of a Fund's investments. At a referendum in June 2016, the United Kingdom (the “U.K.”) voted to leave the European Union (“EU”) thereby initiating the British exit from the EU (commonly known as “Brexit”). In March 2017, the U.K. formally notified the European Council of the U.K.'s intention to withdraw from the EU pursuant to Article 50 of the Treaty on European Union. This formal notification began a multi-year period of negotiations regarding the terms of the U.K.'s exit from the EU, which formally occurred on January 31, 2020. The U.K. entered into a transition period where it remained subject to EU rules but had no role in the EU law-making process. During this transition period, U.K. and EU representatives negotiated the terms of their future relationship. The transition period concluded on December 31, 2020 and the U.K. left the EU single market and customs union under the terms of a new trade agreement. The agreement governs the new relationship between the U.K. and EU with respect to trading goods and services but critical aspects of the relationship remain unresolved and subject to further negotiation and agreement. There is still considerable uncertainty relating to the potential consequences associated with the exit including whether the U.K.'s exit will increase the likelihood of other countries also departing the EU. Brexit may have a significant impact on the U.K., Europe, and global economies, which may result in increased volatility and illiquidity, new legal and regulatory uncertainties and potentially lower economic growth for these economies that could potentially have an adverse effect on the value of the Fund's investments. Securities and financial markets may be susceptible to market manipulation or other fraudulent trade practices, which could disrupt the orderly functioning of these markets or adversely affect the values of investments traded in these markets, including investments held by a Fund. To the extent a Fund has focused its investments in the market or index of a particular region, adverse geopolitical and other events could have a disproportionate impact on the Fund.

Market Risk. Market prices of investments held by a Fund will go up or down, sometimes rapidly or unpredictably. A Fund's investments are subject to changes in general economic conditions, general market fluctuations and the risks inherent in investment in securities markets. Investment markets can be volatile, and prices of investments can change substantially due to various factors, including, but not limited to, economic growth or recession, changes in interest rates, changes in actual or perceived creditworthiness of issuers and general market liquidity. Even if general economic conditions do not change, the value of an investment in a Fund could decline if the particular industries, sectors or companies in which the Fund invests do not perform well or are adversely affected by events. Further, legal, political, regulatory and tax changes also may cause fluctuations in markets and securities prices. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, or other events could have a significant impact on a Fund and its investments.

An outbreak of a respiratory disease caused by a novel coronavirus (known as COVID-19) first detected in China in December 2019 has resulted in a global pandemic and major disruptions to economies and markets around the world, including the United States. Although the long-term economic fallout of COVID-19 is difficult to predict, it has contributed to, and may continue to contribute to, market volatility, inflation and systemic economic weakness, and trading in many instruments was and may continue to be disrupted as a result. Liquidity for many instruments was and may continue to be greatly reduced for periods of time. Some interest rates have been very low and in some cases yields are negative. Governments and central banks, including the Federal Reserve in the United States, have taken extraordinary and unprecedented actions to support local and global economies and the financial markets. The impact of these measures, and whether they will be effective to mitigate the economic and market disruption, will not be known for some time. The foregoing could result in disruptions to the services provided to a Fund by its service providers.

Market Volatility; Government Intervention Risk. Market dislocations and other external events, such as the failures or near failures of significant financial institutions, dislocations in investment or currency markets, corporate or governmental defaults or credit downgrades, or poor collateral performance, may subject a Fund to significant risk of substantial volatility and loss. Governmental and regulatory authorities have taken, and may in the future take, actions to provide or

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arrange credit supports to financial institutions whose operations have been compromised by credit market dislocations and to restore liquidity and stability to financial systems in their jurisdictions; the implementation of such governmental interventions and their impact on both the markets generally and a Fund's investment program in particular can be uncertain. Governmental and non-governmental issuers may default on, or be forced to restructure, their debts, and other issuers may face difficulties obtaining credit. Defaults or restructurings by governments or others of their debts could have substantial adverse effects on economies, financial markets, and asset valuations around the world. Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including interest rate increases or contrary actions by different governments, or investor perception that these efforts are not succeeding, could negatively affect financial markets generally as well as the values and liquidity of certain securities.

Master/Feeder Structure Risk. Each Fund pursues its objective by investing substantially all of its assets in another pooled investment vehicle (a “master fund”). The ability of a Fund to meet its investment objective is directly related to the ability of the master fund to meet its investment objective. The ability of a Fund to meet its objective may be adversely affected by the purchase and redemption activities of other investors in the master fund. The ability of a Fund to meet redemption requests will depend on its ability to redeem its interest in the master fund. The Adviser or an affiliate serves as investment adviser to the master fund, leading to potential conflicts of interest. For example, the Adviser or its affiliates will receive fees based on the amount of assets invested in the master fund. Investment by a Fund in the master fund may be beneficial in the management of the master fund, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a master fund sponsored or managed by the Adviser or its affiliates in lieu of investments by a Fund directly in portfolio securities, or may have an incentive to invest in such master fund over a master fund sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a master fund sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a master fund sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so. A Fund will bear its pro rata portion of the expenses incurred by the master fund.

Money Market Fund Regulatory Risk. Money market funds and the securities they invest in are subject to comprehensive regulations. The enactment of new legislation or regulations, as well as changes in interpretation and enforcement of current laws, may affect the manner of operation, performance and/or yield of money market funds. The SEC has proposed amendments to money market fund regulation that if adopted as proposed would, among other things, increase the daily and weekly liquid asset requirements, remove liquidity fees and redemption gate provisions and require institutional prime money market funds to use swing pricing. Such amendments may, if adopted, limit the Fund's investment flexibility and reduce its ability to generate returns.

Money Market Risk-Floating NAV (principal risk for the ESG Liquid Reserves Fund and ILR Fund). The Fund does not maintain a constant net asset value per share. The value of the Fund's Shares is calculated to four decimal places and will vary reflecting the value of the portfolio of investments held by the Fund. It is possible to lose money by investing in the Fund.

Money Market Risk (principal risk for the U.S. Government Fund, Treasury Fund and Treasury Plus Fund). An investment in a money market fund is not a deposit of any bank and is not insured or guaranteed by the FDIC or any other government agency. Although a money market fund generally seeks to preserve the value of its shares at $1.00 per share, there can be no assurance that it will do so, and it is possible to lose money by investing in a money market fund. A major or unexpected change in interest rates or a decline in the credit quality of an issuer or entity providing credit support, an inactive trading market for money market instruments, or adverse market, economic, industry, political, regulatory, geopolitical, and other conditions could cause a money market fund's share price to fall below $1.00. It is possible that a money market fund will issue and redeem shares at $1.00 per share at times when the fair value of the money market fund's portfolio per share is more or less than $1.00. A money market fund may be permitted or required to impose redemption fees or to impose limitations on redemptions during periods of high illiquidity in the markets for the investments held by it. None of State Street Corporation, State Street, State Street Global Advisors, SSGA FM or their affiliates (collectively, the “State Street Entities”) guarantee the value of an investment in a money market fund at $1.00 per share. Investors should have no expectation of capital support to a money market fund from the State Street Entities.

Mortgage-Related and Other Asset-Backed Securities Risk (principal risk for the ESG Liquid Reserves Fund, ILR Fund and U.S. Government Fund). Investments in mortgage-related and other asset-backed securities are subject to the risk of significant credit downgrades, illiquidity, and defaults to a greater extent than many other types of fixed income investments. The liquidity of mortgage-related and asset-backed securities may change over time. Mortgage-related securi-

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ties represent a participation in, or are secured by, mortgage loans. Other asset-backed securities are typically structured like mortgage-related securities, but instead of mortgage loans or interests in mortgage loans, the underlying assets may include, for example, items such as motor vehicle installment sales or installment loan contracts, leases on various types of real and personal property, and receivables from credit card agreements. During periods of falling interest rates, mortgage-related and other asset-backed securities, which typically provide the issuer with the right to prepay the security prior to maturity, may be prepaid, which may result in a Fund having to reinvest the proceeds in other investments at lower interest rates. During periods of rising interest rates, the average life of mortgage-related and other asset-backed securities may extend because of slower-than expected principal payments. This may lock in a below market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. As a result, mortgage-related and other asset-backed securities may have less potential for capital appreciation during periods of declining interest rates than other debt securities of comparable maturities, although they may have a similar risk of decline in market values during periods of rising interest rates. Prepayment rates are difficult to predict and the potential impact of prepayments on the value of a mortgage-related or other asset-backed security depends on the terms of the instrument and can result in significant volatility. The price of a mortgage-related or other asset-backed security also depends on the credit quality and adequacy of the underlying assets or collateral. Mortgage-related or other asset-backed securities issued by non-governmental issuers (such as commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers) will generally entail greater credit risk than obligations guaranteed by the U.S. Government. Defaults on the underlying assets, if any, may impair the value of a mortgage-related or other asset-backed security. For some asset-backed securities in which a Fund invests, such as those backed by credit card receivables, the underlying cash flows may not be supported by a security interest in a related asset. Moreover, the values of mortgage-related and other asset-backed securities may be substantially dependent on the servicing of the underlying asset pools, and are therefore subject to risks associated with the negligence or malfeasance by their servicers and to the credit risk of their servicers. In certain situations, the mishandling of related documentation may also affect the rights of securities holders in and to the underlying collateral. There may be legal and practical limitations on the enforceability of any security interest granted with respect to underlying assets, or the value of the underlying assets, if any, may be insufficient if the issuer defaults.

Non-U.S. Securities Risk (principal risk for the ESG Liquid Reserves Fund and ILR Fund). Investments in securities of non-U.S. issuers (including depositary receipts) entail risks not typically associated with investing in securities of U.S. issuers. Similar risks may apply to securities traded on a U.S. securities exchange that are issued by entities with significant exposure to non-U.S. countries. In certain countries, legal remedies available to investors may be more limited than those available with regard to U.S. investments. Income and gains with respect to investments in certain countries may be subject to withholding and other taxes. There may be less information publicly available about a non-U.S. entity than about a U.S. entity, and many non-U.S. entities are not subject to accounting, auditing, and financial reporting standards, regulatory framework and practices comparable to those in the United States. The securities of some non-U.S. entities are less liquid and at times more volatile than securities of comparable U.S. entities, and could become subject to sanctions or embargoes that adversely affect a Fund's investment. Non-U.S. transaction costs, such as brokerage commissions and custody costs may be higher than in the U.S. In addition, there may be a possibility of nationalization or expropriation of assets, imposition of currency exchange controls, confiscatory taxation, and diplomatic developments that could adversely affect the values of a Fund's investments in certain non-U.S. countries. Investments in securities of non-U.S. issuers also are subject to foreign political and economic risk not associated with U.S. investments, meaning that political events (civil unrest, national elections, changes in political conditions and foreign relations, imposition of exchange controls and repatriation restrictions), social and economic events (labor strikes, rising inflation) and natural disasters occurring in a country where a Fund invests could cause the Fund's investments in that country to experience gains or losses.

Rapid Changes in Interest Rates. The values of instruments held by a Fund may be adversely affected by rapid changes in interest rates. Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause a Fund to sell portfolio securities at a loss to satisfy those requests. Significant losses would negatively affect the NAV per share of the ILR Fund and the ESG Liquid Reserves Fund and, in the case of the U.S. Government Fund, Treasury Fund and Treasury Plus Fund, could impair the Fund's ability to maintain a stable share price of $1.00.

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Reinvestment Risk (principal risk for the ESG Liquid Reserves Fund, ILR Fund and U.S. Government Fund). Income from a Fund's portfolio may decline when the Fund invests the proceeds from investment income, sales of portfolio securities or matured, traded or called debt obligations. For instance, during periods of declining interest rates, an issuer of debt obligations may exercise an option to redeem securities prior to maturity, forcing a Fund to reinvest the proceeds in lower-yielding securities. A decline in income received by a Fund from its investments is likely to have a negative effect on the yield and total return of the Fund Shares.

Repurchase Agreement Risk (principal risk for the ESG Liquid Reserves Fund, ILR Fund, U.S. Government Fund and Treasury Plus Fund). A repurchase agreement is an agreement to buy a security from a seller at one price and a simultaneous agreement to sell it back to the original seller at an agreed-upon price, typically representing the purchase price plus interest. Repurchase agreements may be viewed as loans made by a Fund which are collateralized by the securities subject to repurchase. A Fund's investment return on such transactions will depend on the counterparty's willingness and ability to perform its obligations under a repurchase agreement. If a Fund's counterparty should default on its obligations and a Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, a Fund may realize a loss.

Restricted Securities Risk (principal risk for the ESG Liquid Reserves Fund and ILR Fund). A Fund may hold securities that have not been registered for sale to the public under the U.S. federal securities laws pursuant to an exemption from registration. These securities may be less liquid than securities registered for sale to the general public. The liquidity of a restricted security may be affected by a number of factors, including, among others: (i) the creditworthiness of the issuer; (ii) the frequency of trades and quotes for the security; (iii) the number of dealers willing to purchase or sell the security and the number of other potential purchasers; (iv) dealer undertakings to make a market in the security; (v) the nature of any legal restrictions governing trading in the security; and (vi) the nature of the security and the nature of marketplace trades. There can be no assurance that a liquid trading market will exist at any time for any particular restricted security. Also, restricted securities may be difficult to value because market quotations may not be readily available, and the securities may have significant volatility.

Risk of Investment in Other Pools (principal risk for the ESG Liquid Reserves Fund and ILR Fund). If a Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. A Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of a Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. A Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by a Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so.

Risks Related to ECDs, ETDs and YCDs (principal risk for the ESG Liquid Reserves Fund and ILR Fund). Banks issuing ECDs, ETDs and YCDs are not necessarily subject to the same regulatory requirements that apply to domestic banks, such as loan limitations, examinations and reserve, accounting, auditing, recordkeeping and public reporting requirements. Obligations of foreign issuers also involve risks such as future unfavorable political and economic developments, withholding or other tax, seizures of foreign deposits, currency controls, interest limitations, and other governmental restrictions that might affect repayment of principal or payment of interest, or the ability to honor a credit commitment.

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Section 4(a)(2) Commercial Paper and Rule 144A Securities Risk (principal risk for the ESG Liquid Reserves Fund and ILR Fund). A Fund may invest in commercial paper issued in reliance on the private placement exemption from registration afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (the “1933 Act”). This commercial paper is commonly called “Section 4(a)(2) paper.” A Fund may also invest in securities that may be offered and sold only to “qualified institutional buyers” under Rule 144A of the 1933 Act (“Rule 144A securities”).

Section 4(a)(2) paper is sold to institutional investors who must agree to purchase the paper for investment and not with a view to public distribution. Any resale by the purchaser must be in a transaction exempt from the registration requirements of the 1933 Act. Section 4(a)(2) paper normally is resold to other institutional investors like a Fund through or with the assistance of the issuer or investment dealers that make a market in Section 4(a)(2) paper. As a result, it suffers from liquidity risk, the risk that the securities may be difficult to value because of the absence of an active market and the risk that it may be sold only after considerable expense and delay, if at all. Rule 144A securities generally must be sold only to other qualified institutional buyers.

Section 4(a)(2) paper and Rule 144A securities will not be considered illiquid for purposes of a Fund's limitation on illiquid securities if the Adviser (pursuant to guidelines adopted by the Board) determines that a liquid trading market exists for the securities in question. There can be no assurance that a liquid trading market will exist at any time for any particular Section 4(a)(2) paper or Rule 144A securities.

Significant Exposure to U.S. Government Agencies or Instrumentalities Risk (principal risk for the U.S. Government Fund). To the extent a Fund focuses its investments in securities issued or guaranteed by U.S. government agencies or instrumentalities, any market movements, regulatory changes or changes in political or economic conditions that affect the U.S. government agencies or instrumentalities in which the Fund invests may have a significant impact on a Fund's performance. Events that would adversely affect the market prices of securities issued or guaranteed by one government agency or instrumentality may adversely affect the market price of securities issued or guaranteed by other government agencies or instrumentalities.

Stable Share Price Risk (principal risk for the U.S. Government Fund, Treasury Fund and Treasury Plus Fund). If the market value of one or more of the Fund's investments changes substantially, the Fund may not be able to maintain a stable share price of $1.00. This risk typically is higher during periods of rapidly changing interest rates or when issuer credit quality generally is falling, and is made worse when the Fund experiences significant redemption requests.

U.S. Government Securities Risk (principal risk for the ESG Liquid Reserves Fund, ILR Fund and U.S. Government Fund). U.S. government securities, such as Treasury bills, notes and bonds and mortgage-backed securities guaranteed by the Government National Mortgage Association (“Ginnie Mae”), are supported by the full faith and credit of the United States; others are supported by the right of the issuer to borrow from the U.S. Treasury; others are supported by the discretionary authority of the U.S. government to purchase the agency's obligations; and still others are supported only by the credit of the issuing agency, instrumentality, or enterprise. Although U.S. government-sponsored enterprises such as the Federal Home Loan Mortgage Corporation (“Freddie Mac”) and the Federal National Mortgage Association (“Fannie Mae”) may be chartered or sponsored by Congress, they are not funded by Congressional appropriations, and their securities are not issued by the U.S. Treasury nor supported by the full faith and credit of the U.S. government. There is no assurance that the U.S. government would provide financial support to its agencies and instrumentalities if not required to do so. In addition, certain governmental entities have been subject to regulatory scrutiny regarding their accounting policies and practices and other concerns that may result in legislation, changes in regulatory oversight and/or other consequences that could adversely affect the credit quality, availability, or investment character of securities issued by these entities. The value and liquidity of U.S. government securities may be affected adversely by changes in the ratings of those securities. Securities issued by the U.S. Treasury historically have been considered to present minimal credit risk. The downgrade in the long-term U.S. credit rating by at least one major rating agency has introduced greater uncertainty about the ability of the U.S. to repay its obligations. A further credit rating downgrade or a U.S. credit default could decrease the value and increase the volatility of a Fund's investments.

U.S. Treasury Obligations Risk (principal risk for the Treasury Fund, Treasury Plus Fund and U.S. Government Fund). U.S. Treasury obligations may differ from other securities in their interest rates, maturities, times of issuance and other characteristics. Similar to other issuers, changes to the financial condition or credit rating of the U.S. government may cause the value of a Fund's U.S. Treasury obligations to decline. The total public debt of the United States as a percent of gross domestic product grew rapidly after the financial crisis of 2008 and has remained at a historically high level. Although high debt levels do not necessarily indicate or cause economic problems, they may create certain systemic

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risks if sound debt management practices are not implemented. A high national debt level may increase market pressures to meet government funding needs, which may drive debt cost higher and cause a country to sell additional debt, thereby increasing refinancing risk. A high national debt also raises concerns that a government will not be able to make principal or interest payments when they are due. In the worst case, unsustainable debt levels can cause a decline in the value of the dollar (which may lead to inflation), and can prevent the U.S. government from implementing effective counter-cyclical fiscal policy in economic downturns. On August 5, 2011, Standard & Poor's Ratings Services downgraded U.S. Treasury securities from AAA rating to AA+ rating. Standard & Poor's Ratings Services stated that its decision was prompted by its view on the rising public debt burden and its perception of greater policymaking uncertainty. A downgrade of the ratings of U.S. government debt obligations, which are often used as a benchmark for other borrowing arrangements, could result in higher interest rates for individual and corporate borrowers, cause disruptions in the international bond markets and have a substantial negative effect on the U.S. economy. A downgrade of U.S. Treasury securities from another ratings agency or a further downgrade below AA+ rating by Standard & Poor's Ratings Services may cause the value of the Fund's U.S. Treasury obligations to decline. In recent years, impasses in Congress regarding the federal budget have caused repeated temporary Federal government shutdowns. While Congress has temporarily suspended the debt limit from time to time, the risks that the U.S. government will not adopt a long-term budget or deficit reduction plan, of one or more additional Federal government shutdowns or of future failures to not increase the Federal government's debt limit, may affect investor and consumer confidence and may adversely impact financial markets and the broader economy, perhaps suddenly and to a significant degree.

Variable and Floating Rate Securities Risk. Variable or floating rate securities are debt securities with variable or floating interest rates payments. Variable or floating rate securities bear rates of interest that are adjusted periodically according to formulae intended generally to reflect market rates of interest and allow a Fund to participate (determined in accordance with the terms of the securities) in increases in interest rates through upward adjustments of the coupon rates on the securities. However, during periods of increasing interest rates, changes in the coupon rates may lag behind the changes in market rates or may have limits on the maximum increases in coupon rates. Alternatively, during periods of declining interest rates, the coupon rates on such securities will typically readjust downward resulting in a lower yield. A Fund may also invest in variable or floating rate equity securities, whose dividend payments vary based on changes in market rates of interest or other factors.

Zero-Coupon Bond Risk (principal risk for the ESG Liquid Reserves Fund and ILR Fund). Zero-coupon bonds are debt obligations that are generally issued at a discount and payable in full at maturity, and that do not provide for current payments of interest prior to maturity. Zero-coupon bonds usually trade at a deep discount from their face or par values and are subject to greater market value fluctuations from changing interest rates than debt obligations of comparable maturities that make current distributions of interest. When interest rates rise, the values of zero-coupon bonds fall more rapidly than securities paying interest on a current basis, because a Fund is unable to reinvest interest payments at the higher rates.

Additional Information About Non-Principal Investment Strategies and Risks

The investments described below reflect the Funds' and the Portfolios' current practices. In addition to the principal risks described above, other risks are described in some of the descriptions of the investments below:

Conflicts of Interest Risk. An investment in a Fund will be subject to a number of actual or potential conflicts of interest. For example, the Adviser or its affiliates may provide services to a Fund, such as securities lending agency services, custodial, administrative, bookkeeping, and accounting services, transfer agency and shareholder servicing, securities brokerage services, and other services for which the Fund would compensate the Adviser and/or such affiliates. The Funds may invest in other pooled investment vehicles sponsored, managed, or otherwise affiliated with the Adviser. There is no assurance that the rates at which a Fund pays fees or expenses to the Adviser or its affiliates, or the terms on which it enters into transactions with the Adviser or its affiliates will be the most favorable available in the market generally or as favorable as the rates the Adviser or its affiliates make available to other clients. Because of its financial interest, the Adviser will have an incentive to enter into transactions or arrangements on behalf of a Fund with itself or its affiliates in circumstances where it might not have done so in the absence of that interest, provided that the Adviser will comply with applicable regulatory requirements.

The Adviser and its affiliates serve as investment adviser to other clients and may make investment decisions that may be different from those that will be made by the Adviser on behalf of the Funds. For example, the Adviser may provide asset allocation advice to some clients that may include a recommendation to invest in or redeem from particular issu-

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ers while not providing that same recommendation to all clients invested in the same or similar issuers. The Adviser may (subject to applicable law) be simultaneously seeking to purchase (or sell) investments for a Fund and to sell (or purchase) the same investment for accounts, funds, or structured products for which it serves as asset manager, or for other clients or affiliates. The Adviser and its affiliates may invest for clients in various securities that are senior, pari passu or junior to, or have interests different from or adverse to, the securities that are owned by a Fund. The Adviser or its affiliates, in connection with its other business activities, may acquire material nonpublic confidential information that may restrict the Adviser from purchasing securities or selling securities for itself or its clients (including the Funds) or otherwise using such information for the benefit of its clients or itself.

The foregoing does not purport to be a comprehensive list or complete explanation of all potential conflicts of interests which may affect a Fund. A Fund may encounter circumstances, or enter into transactions, in which conflicts of interest that are not listed or discussed above may arise.

Cybersecurity Risk. With the increased use of technologies such as the Internet and the dependence on computer systems to perform business and operational functions, funds (such as the Funds) and their service providers (including the Adviser) may be prone to operational and information security risks resulting from cyber-attacks and/or technological malfunctions. In addition, the global spread of COVID-19 has caused the Funds, the Portfolios and their service providers to implement business continuity plans, including widespread use of work-from-home arrangements. In general, cyber-attacks are deliberate, but unintentional events may have similar effects. 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, a Portfolio, the Adviser or a custodian, transfer agent, or other affiliated or third-party service provider may adversely affect a Fund or its shareholders. For instance, cyber-attacks or technical malfunctions may interfere with the processing of shareholder or other transactions, affect a Fund's ability to calculate its NAV, cause the release of private shareholder information or confidential Fund information, impede trading, cause reputational damage, and subject a Fund to regulatory fines, penalties or financial losses, reimbursement or other compensation costs, and additional compliance costs. Cyber-attacks or technical malfunctions may render records of Fund assets and transactions, shareholder ownership of Fund Shares, and other data integral to the functioning of a Fund inaccessible or inaccurate or incomplete. A Fund may also incur substantial costs for cybersecurity risk management in order to prevent cyber incidents in the future. A Fund and its shareholders could be negatively impacted as a result. While the Adviser has established business continuity plans and systems designed to minimize the risk of cyber-attacks through the use of technology, processes and controls, there are inherent limitations in such plans and systems, including the possibility that certain risks have not been identified, given the evolving nature of this threat. Each Fund relies on third-party service providers for many of its day-to-day operations, and will be subject to the risk that the protections and protocols implemented by those service providers will be ineffective to protect the Fund from cyber-attack. The Adviser does not control the cybersecurity plans and systems put in place by third-party service providers, and such third-party service providers may have limited indemnification obligations to the Adviser or the Funds. Similar types of cybersecurity risks or technical malfunctions also are present for issuers of securities in which each Fund invests, which could result in material adverse consequences for such issuers, and may cause a Fund's investment in such securities to lose value.

LIBOR Risk. A Fund's payment obligations, financing terms and investments in certain instruments (including debt securities and derivatives) may rely in some fashion upon the London-Interbank Offered Rate (“LIBOR”). LIBOR is an average interest rate, determined by the ICE Benchmark Administration (the administrator of LIBOR), that banks offer to charge one another for the use of short-term money. In 2017, the U.K. Financial Conduct Authority announced its intention to cease compelling banks to provide the quotations needed to sustain LIBOR after 2021. IBA ceased publication of most LIBOR settings on a representative basis at the end of 2021 and is expected to cease publication of a majority of U.S. dollar LIBOR settings on a representative basis after June 30, 2023. In addition, global regulators have announced that, with limited exceptions, no new LIBOR-based contracts should be entered into after 2021. Actions by regulators have resulted in the establishment of alternative reference rates to LIBOR in most major currencies. Various financial industry groups have been planning for the transition away from LIBOR and markets are developing in response to these new rates, but questions around the liquidity of the new rates and how to appropriately adjust these rates to eliminate any economic value transfer at the time of transition remain a significant concern. The transition away from and eventual elimination of LIBOR may involve, among other things, increased volatility or illiquidity in markets for instruments that rely on LIBOR, particularly insofar as the documentation governing such instruments does not include “fall back” provi-

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sions addressing the transition from LIBOR. Uncertainty and volatility arising from the transition may result in a reduction in the value of certain LIBOR-based instruments held by a Fund or reduce the effectiveness of related transactions such as hedges. Any such effects of the transition away from LIBOR, as well as other unforeseen effects, could result in losses to a Fund.

Risk of Investment in Other Pools (risk for the U.S. Government Fund, Treasury Fund and Treasury Plus Fund). If a Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected. A Fund is exposed indirectly to all of the risks applicable to an investment in such other pool. In addition, lack of liquidity in the underlying pool could result in its value being more volatile than the underlying portfolio of securities, and may limit the ability of a Fund to sell or redeem its interest in the pool at a time or at a price it might consider desirable. The investment policies and limitations of the other pool may not be the same as those of the Fund; as a result, the Fund may be subject to additional or different risks, or may achieve a reduced investment return, as a result of its investment in another pool. If a pool is an exchange-traded fund or other product traded on a securities exchange or otherwise actively traded, its shares may trade at a premium or discount to their NAV, an effect that might be more pronounced in less liquid markets. A Fund bears its proportionate share of the fees and expenses of any pool in which it invests. The Adviser or an affiliate may serve as investment adviser to a pool in which the Fund may invest, leading to potential conflicts of interest. For example, the Adviser or its affiliates may receive fees based on the amount of assets invested in the pool. Investment by a Fund in the pool may be beneficial to the Adviser or an affiliate in the management of the pool, by helping to achieve economies of scale or enhancing cash flows. Due to this and other factors, the Adviser may have an incentive to invest a Fund's assets in a pool sponsored or managed by the Adviser or its affiliates in lieu of investments by the Fund directly in portfolio securities, or may have an incentive to invest in the pool over a pool sponsored or managed by others. Similarly, the Adviser may have an incentive to delay or decide against the sale of interests held by a Fund in a pool sponsored or managed by the Adviser or its affiliates. It is possible that other clients of the Adviser or its affiliates will purchase or sell interests in a pool sponsored or managed by the Adviser or its affiliates at prices and at times more favorable than those at which a Fund does so.

Temporary Defensive Positions. In response to actual or perceived adverse market, economic, political, or other conditions, a Fund may (but will not necessarily), without notice, depart from its principal investment strategies by temporarily investing for defensive purposes. While investing defensively, the Fund may maintain a substantial portion of its assets in cash, on which the Fund may earn little if any income. If a Fund invests for defensive purposes, it may not achieve its investment objective. In addition, the defensive strategy may not work as intended.

Portfolio Holdings Disclosure

The Funds' portfolio holdings disclosure policy is described in the Statement of Additional Information (“SAI”).

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Management and Organization

Each Fund is a separate, diversified series of the State Street Institutional Investment Trust (the “Trust”), which is an open-end management investment company organized as a business trust under the laws of the Commonwealth of Massachusetts.

Each Fund invests as part of a “master/feeder” structure. Each Fund currently seeks to achieve its investment objective by investing substantially all of its investable assets in a corresponding Portfolio, a separate mutual fund, that has substantially identical investment objective, investment policies, and risks as the Fund. All discussions about a Fund's investment objective, policies and risks should be understood to refer also to the investment objectives, policies and risks of the corresponding Portfolio.

A Fund can withdraw its investment in a Portfolio if, at any time, the Fund's Board of Trustees determines that it would be in the best interests of the Fund's shareholders, or if the investment objectives of the corresponding Portfolio changed so that they were inconsistent with the objectives of the Fund. If a Fund withdraws its investment from a Portfolio, the Fund may invest all of its assets in another mutual fund that has the same investment objective as the Fund, the Adviser may directly manage the Fund's assets, or the Board may take such other action it deems appropriate and in the best interests of shareholders of the Fund, which may include liquidation of the Fund.

Investment Adviser

SSGA FM serves as the investment adviser to each Fund  and corresponding Portfolio and, subject to the oversight of the Board, is responsible for the investment management of each Fund. The Adviser provides an investment management program for each Fund and manages the investment of each Fund's assets. The Adviser is a wholly-owned subsidiary of State Street Global Advisors, Inc., which itself is a wholly-owned subsidiary of State Street Corporation. The Adviser is registered with the U.S. Securities and Exchange Commission (“SEC”) under the Investment Advisers Act of 1940, as amended. The Adviser and certain other affiliates of State Street Corporation make up SSGA. SSGA is one of the world's largest institutional money managers and the investment management arm of State Street Corporation. As of December 31, 2021, the Adviser managed approximately $841.33 billion in assets and SSGA managed approximately $4.14 trillion in assets. The Adviser's principal business address is One Iron Street, Boston, Massachusetts 02210.

SSGA FM intends to support inclusion and diversity initiatives by making an annual donation out of its own assets in an amount equal to or more than 20% of the annual management fees received with respect to the assets invested in the Opportunity Class shares of each Fund. Donations will be made to charitable organizations working in congruence with State Street Corporation's 10 Actions to Address Racism and Inequality. Management fees are determined net of fee waivers, expense reimbursements, net asset value support payments and similar amounts. The donation program will continue throughout the life of the Opportunity Class shares. The charitable organizations will not participate in, or have any influence on the day‑to‑day operations of, the Funds or the Adviser's management of the Funds.

Each Fund has entered into an investment advisory agreement with the Adviser pursuant to which the Adviser will manage the Fund's assets directly, for compensation paid at an annual rate of 0.05% of the Fund's average daily net assets, in the event that the Fund were to cease investing substantially all of its assets in its corresponding Portfolio or another investment company with essentially the same investment objectives and policies as the Fund. The Adviser does not receive any management fees from a Fund under that agreement so long as the Fund continues to invest substantially all of its assets in the corresponding Portfolio or in another investment company with essentially the same investment objectives and policies as the Fund. The Adviser places all orders for purchases and sales of the Portfolios' investments. For the year ended December 31, 2021, the effective management fee paid, reflecting certain fee waivers and expense reimbursements of the Adviser, was 0.00% for ESG Liquid Reserves Portfolio, 0.05% for Money Market Portfolio, 0.05% for Treasury Portfolio 0.05% for Treasury Plus Portfolio and 0.05% for U.S. Government Portfolio.

Total Annual Fund Operating Expense Waivers. SSGA FM, as the investment adviser to each Fund is contractually obligated, through April 30, 2023 (i) to waive up to the full amount of the advisory fee payable by each Fund, and/or (ii) to reimburse a Fund for expenses to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, acquired fund fees, any class-specific expenses, such as distribution, shareholder servicing, sub-transfer agency and administration fees) exceed 0.07% of average daily net assets on an annual basis (the “Total Annual Fund Operating Expense Waiver”). The Total Annual Fund Operating Expense Waiver may not be terminated prior to April 30, 2023 with respect to any Fund except with approval of the Fund's Board of Trustees.

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In addition to any contractual expense limitation for a Fund which is described in the Fund Summaries, each of the Adviser and State Street Global Advisors Funds Distributors, LLC (each a “Service Provider”) also may voluntarily reduce all or a portion of its fees and/or reimburse expenses for a Fund or a share class to the extent necessary to maintain a certain minimum net yield, which may vary from time to time in SSGA FM's sole discretion (any such waiver or reimbursement of expenses being referred to herein as a “Voluntary Reduction”). The Adviser may, in its sole discretion, implement the Voluntary Reduction for some Funds, or some share classes of a Fund, and not others. The amount of any Voluntary Reduction may differ between Funds and share classes in the Adviser's sole discretion. The business objectives of the Adviser and its affiliates and their broader relationships with certain Fund shareholders, Financial Intermediaries or distribution channels could give the Adviser an incentive to implement the Voluntary Reduction for some Funds or share classes and not others, or to implement it to a greater degree for some Funds or share classes than others. Under an agreement with the Service Providers relating to the Voluntary Reduction, the Funds and the Portfolios have agreed to reimburse the Service Providers for the full dollar amount of any Voluntary Reduction beginning on May 1, 2020, subject to certain limitations. Each Service Provider may, in its sole discretion, irrevocably waive receipt of any or all reimbursement amounts due from a Fund.

A reimbursement to the Service Provider would increase fund expenses and may negatively impact a Fund's yield during such period. There is no guarantee that the Voluntary Reduction will be in effect at any given time or that a Fund will be able to avoid a negative yield. The Funds have agreed, subject to certain limitations, to reimburse the applicable Service Provider for the full dollar amount of any Voluntary Reduction incurred after May 1, 2020. A Fund is not obligated to reimburse a Service Provider: (1) more than three years after the end of the fiscal year of the Fund in which the Service Provider provided a Voluntary Reduction; (2) in respect of any business day for which the net annualized one‑day yield of the Fund or applicable Class is less than 0.00%; (3) to the extent that the amount of the reimbursement to all Service Providers on any day exceeds fifty percent of the yield (net of all expenses, exclusive of the reimbursement) of the Fund or the applicable class on that day; (4) to the extent that the amount of such reimbursement would cause the Fund's or applicable class's net yield to fall below the Fund's or applicable class's minimum yield; (5) in respect of any such fee waivers and/or expense reimbursements that are necessary to maintain the Fund's Contractual Total Expense Limit (as defined in the Reimbursement Agreement) which is effective at the time of such fee waivers and/or expense reimbursements; or (6) in any manner that would result in a class bearing the cost of a reimbursement to the Service Provider for any class-specific expense (including, without limitation, fees payable in accordance with a plan authorized pursuant to Rule 12b-1 under the 1940 Act, or Shareholder Servicing Agreement or similar arrangement) that was waived or reimbursed to the Fund with respect to a different Class. Any such future reimbursement of an applicable Service Provider may result in the total annual operating expenses with respect to a share class of a Fund exceeding the amount of the expense cap under the contractual expense limitation agreement because the expense is not covered by the agreement.

A discussion regarding the Board's consideration of the Funds' Investment Advisory Agreement is provided in the Funds' Semi-Annual Report to Shareholders for the period ended June 30, 2021.

The Adviser serves as administrator of each Fund. The amount of the fee paid to the Adviser for administrative services may vary by share class. Each Fund currently pays the Adviser an administrative fee at the annual rate of 0.05% in respect of the class of shares in this Prospectus. State Street Bank and Trust Company (“State Street”), a subsidiary of State Street Corporation, serves as the sub-administrator for the Funds for a fee that is paid by the Adviser. State Street also serves as custodian of the Funds for a separate fee that is paid by the Funds. SSGA FM serves as administrator of the Portfolios and State Street serves as sub-administrator and custodian of the Portfolios.

DST Asset Manager Solutions, Inc. is the Funds' transfer agent and dividend disbursing agent (the “Transfer Agent”).

State Street Global Advisors Funds Distributors, LLC serves as the Funds' distributor (“SSGA FD”) pursuant to the Distribution Agreement between SSGA FD and the Trust.

SSGA FD serves as the Funds' shareholder servicing agent pursuant to the Shareholder Servicing Agreement between SSGA FD and the Trust and receives fees from the Funds for the provision and procurement of applicable services. Please see the SAI for more information on SSGA FD's role as the Funds' shareholder servicing agent.

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The Trustees of the Trust oversee generally the operations of the Funds and the Trust. The Trust enters into contractual arrangements with various parties, including, among others, the Funds' investment adviser, custodian, transfer agent, and accountants, who provide services to the Funds. Shareholders are not parties to any such contractual arrangements or intended beneficiaries of those contractual arrangements, and those contractual arrangements are not intended to create in any shareholder any right to enforce them directly against the service providers or to seek any remedy under them directly against the service providers.

This Prospectus provides information concerning the Trust and the Funds that you should consider in determining whether to purchase shares of the Funds. Neither this Prospectus, nor the related SAI, is intended, or should be read, to be or to give rise to an agreement or contract between the Trust or the Funds and any investor, or to give rise to any rights in any shareholder or other person other than any rights under federal or state law that may not be waived.

Shareholder Information

The ESG Liquid Reserves Fund and ILR Fund each determines its NAV per share three times each day on which the New York Stock Exchange (the “NYSE”), the Federal Reserve banks and State Street are open for business (a “Business Day”) at 8:00 a.m., 12:00 p.m. and 3:00 p.m. ET. The price for Fund shares is the NAV next calculated after the purchase order is accepted by a Fund. Orders accepted before 12:00 p.m. will receive the 12:00 p.m. NAV, orders accepted before 3:00 p.m. will receive the 3:00 p.m. NAV, and orders accepted after 3:00 p.m. will receive 8:00 a.m. NAV calculated on the following Business Day. The Fund calculates its NAV to four decimal places.

The NAV of each class of a Fund's shares is calculated by dividing the value of the assets of the Fund attributable to that class less the liabilities of the Fund attributable to that class by the number of shares in the class outstanding. Each Fund values each security or other investment pursuant to guidelines adopted by the Board of Trustees. Securities or other investments may be valued at fair value, as determined in good faith and pursuant to procedures approved by the Portfolio's Board of Trustees, under certain limited circumstances. For example, fair value pricing may be used when market quotations are not readily available or reliable, such as when (i) trading for a security is restricted; or (ii) a significant event, as determined by the Adviser, that may affect the value of one or more securities or other investments held by the Fund occurs after the close of a related exchange but before the determination of the Fund's NAV. Attempts to determine the fair value of securities or other investments introduce an element of subjectivity to the pricing of securities or other investments. As a result, the price of a security or other investment determined through fair valuation techniques may differ from the price quoted or published by other sources and may not accurately reflect the price a Fund would have received had it sold the investment. To the extent that a Fund invests in the shares of other registered open-end investment companies that are not traded on an exchange (mutual funds), such shares are valued at their published net asset values per share as reported by the funds. The prospectuses of these funds explain the circumstances under which the funds will use fair value pricing and the effects of using fair value pricing.

The Treasury Plus Fund and the U.S. Government Fund each determines its NAV per share once each Business Day at 5:00 p.m. ET except for days when the NYSE closes earlier than its regular closing time, in which event those Funds will determines their NAVs at the earlier closing time. The Treasury Fund determines its NAV per share once each Business Day at 2:30 p.m. ET, or the close of the NYSE, whichever is earlier (the time when a Fund determines its NAV per share is referred to herein as the “Valuation Time”). Each Fund seeks to maintain a $1.00 per share NAV and, accordingly, uses the amortized cost valuation method, in compliance with the risk limiting conditions of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “1940 Act”), to value its portfolio instruments. The amortized cost valuation method initially prices an instrument at its cost and thereafter assumes a constant amortization to maturity of any discount or premium, regardless of the impact of fluctuating interest rates on the market value of the instrument.

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Pricing does not occur on NYSE holidays. The Federal Reserve is closed on certain holidays on which the NYSE is open. These holidays are Columbus Day and Veterans Day. On these holidays, you will not be able to purchase shares by wiring Federal Funds because Federal Funds wiring does not occur on days when the Federal Reserve is closed. The Funds reserve the right to accept orders to purchase or redeem shares, or to continue to accept such orders following the close of the NYSE, on any day that is not a Business Day or any day on which the NYSE closes early, provided the Federal Reserve remains open. As noted in this Prospectus, certain Funds may invest in securities listed on foreign exchanges, or otherwise traded in a foreign market, and those securities may trade on weekends or other days when a Fund does not price its shares. Consequently, the NAV of a Fund's shares may change on days when shareholders are not able to purchase or redeem the Fund's shares. The Funds also may establish special hours on those days to determine each Fund's NAV. In the event that the Funds invoke the right to accept orders to purchase or redeem shares on any day that is not a Business Day or adopt special hours of operation, the Fund will post advance notice of these events at:www.ssga.com.

If you hold shares of a Fund through a broker-dealer or other financial intermediary, your intermediary may offer additional services and account features that are not described in this Prospectus. Please contact your intermediary directly for an explanation of these services.

Investing in State Street Institutional Investment Trust Shares

Mutual funds advised by SSGA FM (the “State Street Funds”) and their service providers have a legal obligation to collect from you certain personal information about you at the time you open an account in order to verify your identity and the source of your payment. If you do not provide this information, you may not be able to open an account with the State Street Funds. If the State Street Funds believe that they have uncovered unlawful activity, the State Street Funds and their service providers may close your account and take any action they deem reasonable or required by law. The State Street Funds reserve the right to reject any purchase order.

This section of the Prospectus explains the basics of doing business with the State Street Funds. Carefully read each topic. The policies set forth below regarding the purchase, redemption and exchange of State Street Fund shares are in addition to the “Purchase and Sale of Fund Shares” section contained in the “Fund Summary” portion of this Prospectus. The State Street Funds reserve the right to change the following policies, without notice to shareholders; except that any modification or termination of the exchange privileges described in this Prospectus will be preceded by 60 days' advance notice to shareholders. Please call or check online for current information. Requests for transactions in the State Street Funds will be processed when they are received in “good order.” “Good order” means that the request is in an accurate and complete form, and all applicable documents have been received in such accurate and complete form (including, typically, a signed application and medallion-guaranteed documents), and, for a purchase request, the check or wired funds have cleared.

Purchasing Shares

The Funds offer six classes of shares through this Prospectus: Institutional Class, Administration Class, Investment Class, Investor Class, Premier Class and Opportunity Class is available to you subject to the eligibility requirements set forth below. All classes of a Fund share the same investment objective and investments, but the different share classes have different expense structures and eligibility requirements. You should choose the class with the expense structure that best meets your needs for which you are eligible. In choosing a share class, you should consider the amount you plan to invest. Your investment professional can help you choose the share class that best suits your investment needs.

The chart below summarizes the features of the different share classes. This chart is only a general summary, and you should read the description of each Fund's expenses in each Fund Summary in this Prospectus.

The minimum purchase amount may be waived for specific investors or types of investors, including, without limitation, retirement plans, employees of State Street Corporation and its affiliates and their family. In the case of shareholders purchasing shares through a Financial Intermediary, the minimum purchase amount may be applied at the level of the Financial Intermediary.

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	Institutional Class	Administration Class	Investment Class	Investor Class	Premier Class	Opportunity Class
Minimum Initial Investment	$25,000,000	$1,000	$250	$10,000,000	$250,000,000	$25,000,000
Maximum Investment	None.	None.	None.	None.	None.	None.
Initial Sales Charge	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.	No. Entire purchase price is invested in shares of a Fund.
Deferred (CDSC) Sales Charge	No.	No.	No.	No.	No.	No.
Distribution and/or Service (12b-1) Fees	No.	0.05% annual fee.	0.10% annual fee.	No.	No.	No.
Redemption Fees	No.	No.	No.	No.	No.	No.

Investors pay no sales load to invest in the shares of the Funds. The price for Fund Shares is the NAV per share.

Purchase requests received by a Fund in good order (a purchase request is in good order if it meets the requirements implemented from time to time by the Transfer Agent or authorized agent of the Fund, and for new accounts includes submission of a completed and signed application and all documentation necessary to open an account) on a Business Day will, if payment is received by FedWire, be priced at the NAV next determined after the order is accepted by the Fund. Payments received by FedWire prior to the last Valuation Times (for the ILR Fund generally, 3:00 p.m. ET, unless the Fund closes earlier) will earn dividend accrual for that purchase.

All purchases that are made by check will be priced with the last valuation price and begin earning dividends the following Business Day after the day the order is accepted. (If you purchase shares by check, your order will not be in good form until the Transfer Agent receives federal funds for the check.) All purchase orders are subject to acceptance by the Funds. The Funds intend to be as fully invested as is practicable; therefore, investments must be made in Federal Funds (i.e., monies credited to the account of the Funds' custodian bank by a Federal Reserve Bank).

The minimum initial investment in Institutional Class, Administration, Investment, Investor, Premier and Opportunity shares of the Funds is $25 million, $1 thousand, $250, $10 million, $250 million and $25 million, respectively, although the Adviser may waive the minimum in its discretion. Holdings of related customer accounts may be aggregated for purposes of determining the minimum investment amount. “Related customer accounts” may include but are not limited to accounts held by the same investment or retirement plan, financial institution, broker, dealer or intermediary. The Funds and the Adviser reserve the right to increase or decrease the minimum amount required to open or maintain an account. There is no minimum subsequent investment, except in relation to maintaining certain minimum account balances (See “Redeeming Shares” below). The Funds require prior notification of subsequent investments in excess of $10 million for the Treasury Fund and $50 million for the U.S. Government Fund and Treasury Plus Fund.

The Funds reserve the right to cease accepting investments at any time or to reject any investment order. In addition, the U.S. Government Fund and the Treasury Plus Fund may limit the amount of a purchase order received after 3:00 p.m. ET. The Treasury Fund may limit the amount of a purchase order received after 12:00 p.m. (noon) ET. The ESG Liquid Reserves Fund and ILR Fund each determine its NAV at 8:00 a.m., 12:00 p.m. and 3:00 p.m. ET. The 8:00 a.m., 12:00 p.m. and 3:00 p.m. NAV calculation times are intended to facilitate same day settlement.

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How to Purchase Shares

By Mail:

An initial investment in the Funds must be preceded or accompanied by a completed, signed Institutional Account Application Form, sent to: State Street Funds P.O. Box 219737 Kansas City, MO 64121-9737

By Overnight:

State Street Funds 430 W 7th Street Suite 219737 Kansas City, MO 64105-1407

By Telephone/Fax:

An initial investment in the Funds must be preceded or accompanied by a completed, signed Institutional Account Application Form, faxed to (816) 218-0400. Call the Fund at (866) 392-0869 between the hours of 7:00 a.m. ET and 5:00 p.m. ET to:

➣ confirm receipt of the faxed Institutional Account Application Form (initial purchases only), ➣ request your new account number (initial purchases only), ➣ confirm the amount being wired and wiring bank, and ➣ receive a confirmation number for your purchase order (your trade is not effective until you have received a confirmation number from the Fund).

For your initial investment, send the original, signed Institutional Account Application Form to the address above.

Wire Instructions:

Instruct your bank to transfer money by Federal Funds wire to: State Street Bank and Trust Company 1 Iron Street Boston, MA 02210

ABA# 011000028 DDA# 9904-631-0 State Street Institutional Investment Trust Fund Name Class Name Account Number Account Registration

On Columbus Day and Veterans Day, you will not be able to purchase shares by wiring Federal Funds because the Federal Funds wiring does not occur on those days. Payment for Fund Shares must be in Federal Funds (or converted to Federal Funds by the Transfer Agent) by the close of the Federal Reserve.

The Funds and the Funds' agents are not responsible for transfer errors by the sending or receiving bank and will not be liable for any loss incurred due to a wire transfer not having been received.

Automatic Investment Plan. An Automatic Investment Plan is available for all operational State Street Funds that offer the Administration Class shares. Once an initial investment has been accepted, you may elect to make automatic subsequent investments of $100 or more on a periodic basis (i.e., monthly, quarterly, semi-annually, or annually) by authorizing the Fund to debit your bank checking or savings account through Automated Clearing House (ACH). For the ESG Liquid Reserves Fund and ILR Fund Administration Class shares, purchases made through the Automated Investment Plan will be priced at the last valuation price on the day of the transaction.Once this option has been established, you may call the State Street Funds to make additional automatic purchases, to change the amount of the existing automatic purchase, or to discontinue the service. The Fund reserves the right to cancel your Automatic Investment Plan if any correspondence sent by the Fund to your address of record is returned by the postal service or other delivery service as “undeliverable.” Ask your financial adviser or financial intermediary for details.

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Redeeming Shares

An investor may redeem all or any portion of its investment. Redemption orders are processed at the NAV next determined after a Fund receives a redemption order in good form.

If the ESG Liquid Reserves Fund or the ILR Fund receives a redemption order in good form prior to its last valuation time (generally, 3:00 p.m. ET, unless the Fund closes earlier) on a Business Day, the Fund typically sends payment for redeemed shares on that day, but no later than the next Business Day if redemption proceeds are sent by wire or ACH. If redemption proceeds are sent by check, the Fund typically expects to pay out redemption proceeds on the next Business Day. If a full redemption order is requested, no dividends will accrue with respect to shares on the day the redemption proceeds are sent. If a redemption order is placed after the last valuation time (generally, 3:00 p.m. ET, unless the Fund closes earlier) a Fund typically expects to pay out redemption proceeds on the next Business Day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent). Each Fund reserves the right to pay for redeemed shares within seven days after receiving a redemption order if, in the judgment of the Adviser, an earlier payment could adversely affect the Fund.

Certain special limitations affecting redemptions. The SEC has implemented a number of requirements, including liquidity fees and redemption gates, for money market funds based on the amount of fund assets in “weekly liquid assets,” which generally includes cash, direct obligations of the U.S. government, certain other U.S. government or agency securities, and securities that will mature or are subject to a demand feature that is exercisable and payable within five Business Days. Each Fund will pass through to its investors any liquidity fee or suspension of redemptions imposed by the corresponding Portfolio on the same terms and conditions as imposed by the Portfolio on the Fund.

If a Portfolio's weekly liquid assets fall below 30% of its total assets and the Portfolio's Board of Trustees determines it is in the best interests of the Portfolio, the Portfolio may immediately impose a liquidity fee of no more than 2% and/or temporarily suspend redemptions for up to 10 Business Days in any 90 day period. If a Portfolio's weekly liquid assets fall below 10% of its total assets at the end of any Business Day, the Portfolio will impose a liquidity fee of 1% on all redemptions beginning on the next Business Day, unless the Portfolio's Board determines that imposing such a fee would not be in the best interests of the Portfolio or determines that a lower or higher fee (not to exceed 2%) would be in the best interests of the Portfolio, which would remain in effect until weekly liquid assets return to 30% or the Portfolio's Board determines that the fee is no longer in the best interests of the Portfolio. All liquidity fees payable by a Fund would be passed through to its shareholders, would be payable to the Portfolio and could offset any losses realized by the Portfolio when seeking to honor redemption requests. If liquidity fees are imposed or redemptions are suspended by a Portfolio, the corresponding Fund will notify shareholders on the Fund's website. Each Fund expects to treat such liquidity fees paid to its corresponding Portfolio as reducing proceeds paid to shareholders in redemption of Fund shares, and not constituting income to the Portfolio or the Fund. There may be circumstances under which a Fund may impose its own liquidity fees and/or suspend redemptions based on the level of the Fund's own weekly liquid assets, in which case the Fund will also provide notice to shareholders.

If a Portfolio's weekly liquid assets fall below 10% of its assets on a Business Day, the Portfolio may cease honoring redemptions and liquidate in the discretion of the Portfolio's Board. If a Fund is notified that its Portfolio's weekly liquid assets fall below 10% of the Portfolio's assets and the Portfolio has suspended redemptions and intends to liquidate, the Fund may also do so in the discretion of the Fund's Board. There may be circumstances under which a Fund may cease honoring redemptions and liquidate in the discretion of its Board based on the level of the Fund's own weekly liquid assets. If a Fund ceases honoring redemptions and determines to liquidate, the ILR Fund expects that it would notify shareholders on the Fund's website. Distributions to shareholders of liquidation proceeds may occur in one or more disbursements.

If the Treasury Fund, the Treasury Plus Fund or the U.S. Government Fund receives a redemption order in good form prior to 2:30 p.m. ET for the Treasury Fund and 5:00 p.m. ET for the Treasury Plus Fund and U.S. Government Fund on a Business Day, the Fund typically expects to pay out redemption proceeds on that day, but no later than the next Business Day if redemption proceeds are sent by wire or ACH.

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If redemption proceeds are sent by check, the Fund pays out redemption proceeds on the next Business Day. If a full redemption order is requested, no dividends will accrue with respect to shares on the day the redemption proceeds are sent. If a redemption order is placed after 2:30 p.m. ET for the Treasury Fund and 5:00 p.m. ET for the U.S. Government Fund and the Treasury Plus Fund, the Fund typically expects to pay out redemption proceeds on the next Business Day (and dividends will accrue up to, but not including, the day that redemption proceeds are sent), but no later than the following Business Day. The Fund may postpone and/or suspend redemption and payment beyond the foregoing time periods only as follows:

a)	For any period during which there is a non-routine closure of the Fedwire or applicable Federal Reserve Banks;
b)	For any period (1) during which the NYSE is closed other than customary week-end and holiday closings or (2) during which trading on the NYSE is restricted;
c)	For any period during which an emergency exists as a result of which (1) disposal of securities owned by the Fund is not reasonably practicable or (2) it is not reasonably practicable for the Fund to fairly determine the net asset value of shares of the Fund;
d)	For any period during which the SEC has, by rule or regulation, deemed that (1) trading shall be restricted or (2) an emergency exists;
e)	For any period that the SEC, may by order permit for your protection; or
f)	For any period during which the Fund as part of a necessary liquidation of the fund, has properly postponed and/or suspended redemption of shares and payment in accordance with federal securities laws.

The Treasury Fund, Treasury Plus Fund and U.S. Government Fund are government money market funds that have not elected to be subject to the fees and gates provisions of Rule 2a-7. Although each Fund attempts to maintain its NAV at $1.00 per share, there can be no assurance that it will be successful, and there can be no assurance that a shareholder will receive $1.00 per share upon any redemption.

With respect to the ESG Liquid Reserves Fund and ILR Fund, the right of any investor to receive payment with respect to any redemption may be suspended or the payment of the redemption proceeds postponed beyond 7 days in accordance with Section 22(e) of the 1940 Act and the rules thereunder, including during any period in which the NYSE is closed (other than weekends or holidays) or trading on the NYSE is restricted or if an emergency exists as a result of which disposal by the Fund of securities owned by it is not reasonably practicable or it is not reasonably practicable for the Fund fairly to determine the value of its net assets. In addition, the SEC may by order permit suspension of redemptions for the protection of shareholders of the Funds. The ESG Liquid Reserves Fund and the ILR Fund also may permanently suspend redemptions and liquidate if, among other reasons, (i) a Fund, at the end of a business day, has invested less than 10% of its total assets in weekly liquid assets and (ii) the Board, including the Independent Trustees, irrevocably has approved the liquidation of a Fund.

Under normal circumstances, the Funds expect to meet redemption requests by using cash or cash equivalents in its portfolio and/or selling portfolio assets to generate cash. The Funds also may pay redemption proceeds using cash obtained through borrowing arrangements that may be available from time to time.

A Fund may pay all or a portion of your redemption proceeds by giving you securities (for example, if the Fund reasonably believes that a cash redemption may have a substantial impact on the Fund and its remaining shareholders). You may pay transaction costs to dispose of the securities, and you may receive less for them than the price at which they were valued for purposes of the redemption. In addition, you will be subject to the market risks associated with such securities until such time as you choose to dispose of the security.

During periods of deteriorating or stressed market conditions or during extraordinary or emergency circumstances, a Fund may be more likely to pay redemption proceeds with cash obtained through short-term borrowing arrangements (if available) or by giving you securities.

A request for a partial redemption by an investor whose account balance is below the minimum amount or a request for partial redemption by an investor that would bring the account below the minimum amount may be treated as a request for a complete redemption of the account. These minimums may be different for investments made through certain

57

financial intermediaries as deter- mined by their policies and may be waived in the Adviser's discretion. The Funds reserve the right to modify minimum account requirements at any time with or without prior notice. The Funds also reserve the right to involuntarily redeem an investor's account if the investor's account balance falls below the applicable minimum amount due to transaction activity.

How to Redeem Shares

By Mail:	Send a signed letter to: State Street Institutional Investment Trust Funds P.O. Box 219737 Kansas City, MO 64121-9737
	The letter should include information necessary to process your request as described below. The Fund may require a medallion guarantee in certain circumstances. See “Medallion Guarantees” below.
By Overnight:	State Street Institutional Investment Trust Funds 430 W 7th Street Suite 219737 Kansas City, MO 64105-1407
By Telephone:	Please call (866) 392-0869 between the hours of 7:00 a.m. and 5:00 p.m. ET.
The Funds will need the following information to process your redemption request:
➣ name(s) of account owners;   ➣ account number(s);   ➣ the name of the Fund;   ➣ your daytime telephone number; and   ➣ the dollar amount or number of shares being redeemed.

On any day that the Funds calculate their NAVs earlier than normal, the Funds reserve the right to adjust the times noted above for purchasing and redeeming shares.

Medallion Guarantees. Certain redemption requests must include a medallion guarantee for each registered account owner if any of the following apply:

•	Your account address has changed within the last 10 Business Days.
•	Redemption proceeds are being transferred to an account with a different registration.
•	A wire is being sent to a financial institution other than the one that has been established on your Fund account.
•	Other unusual situations as determined by the Transfer Agent.

The Funds reserve the right to waive medallion guarantee requirements, require a medallion guarantee under other circumstances or reject or delay redemption if the medallion guarantee is not in good form. Medallion guarantees may be provided by an eligible financial institution such as a commercial bank, a Financial Industry Regulatory Authority, Inc. (“FINRA”) member firm such as a stock broker, a savings association or a national securities exchange. A notary public cannot provide a medallion guarantee. The Funds reserve the right to reject a medallion guarantee if it is not provided by a STAMP Medallion guarantor.

About Telephone Transactions. Telephone transactions are convenient but are not free from risk. Neither the Funds nor the Funds' agents will be responsible for any losses resulting from unauthorized telephone transactions if reasonable security procedures are followed. In addition, you are responsible for: (i) verifying the accuracy of all data and information transmitted by telephone, (ii) verifying the accuracy of your account statements immediately upon receipt, and (iii) promptly notifying the Funds of any errors or inaccuracies, including, without limitation, any errors or inaccuracies relating to shareholder data or information transmitted by telephone. During periods of heavy market activity or other times, it may be difficult to reach the Funds by telephone. If you are unable to reach us by telephone, consider sending written instructions.

The Funds may terminate the receipt of redemption orders by telephone at any time, in which case you may redeem shares by other means.

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If you choose to purchase or redeem shares by sending instructions by regular mail, they will not be deemed received in good order until they are released by the post office and redelivered to the Transfer Agent's physical location at 430 W 7th Street Suite 219737 in Kansas City, MO 64105-1407. There will be a time lag, which may be one or more days, between regular mail receipt at the post office box and redelivery to such physical location in Kansas City, and a Fund's NAV may change over those days. You might consider using express rather than regular mail if you believe the time of receipt of your transaction request to be sensitive.

Automatic Withdrawal Plan. An Automatic Withdrawal Plan is available for all operational State Street Funds that offer the Administration Class shares, except for the State Street Institutional Liquid Reserves Fund. If your account balance is over $10,000, you may request periodic (i.e., monthly, quarterly, semi-annually, or annually) automatic cash withdrawals on any Business Day of $100 or more, which can be mailed to you, or any person or entity, you designate or sent through Automated Clearing House (ACH) to your designated bank account. Proceeds from such withdrawals will be transmitted to your designated bank account two Business Days after the redemption of shares occurs. No interest will accrue on the amounts represented by the uncashed redemption check(s). Ask your financial adviser or financial intermediary for details.

Exchanging Shares

An exchange occurs when you use the proceeds from the redemption of shares of a Fund in the State Street Institutional Investment Trust to simultaneously purchase shares of a different Fund in the State Street Institutional Investment Trust. Currently, exchanging shares is allowed from/to the Treasury Plus Fund, U.S. Government Fund, and Treasury Fund. Exchanges may be made between different Funds within the same class (i.e. Institutional Class shares for Institutional Class shares; Investor Class shares for Investor Class shares). The account holding the original shares must be registered in the same name as the account holding the new shares received in the exchange. You may make exchange requests by telephone, or by mail. See Purchasing Shares and Redeeming Shares. Exchanges are subject to the terms applicable to the purchases of the fund into which you are exchanging. Exchange privileges may not be available for mutual funds advised by SSGA FM (the “State Street Funds”) and may be suspended or rejected.

Excessive Trading

Because the Funds are money market funds, the Funds' Board has not adopted policies and procedures with respect to frequent purchases and redemptions of Fund shares by Fund shareholders. Nonetheless, the Funds may take any reasonable action that they deem necessary or appropriate to prevent excessive trading in Fund shares without providing prior notification to the account holder. Such action may include rejecting any purchase, in whole or part, including, without limitation, by a person whose trading activity in Fund shares may be deemed harmful to the Fund. While the Funds attempt to discourage such excessive trading, there can be no guarantee that they will be able to identify investors who are engaging in excessive trading or limit their trading practices. Additionally, frequent trades of small amounts may not be detected. The Funds recognize that they may not always be able to detect or prevent excessive trading or other activity that may disadvantage the Funds or their shareholders.

To reduce expenses, we may mail only one copy of the Funds' Prospectus and each annual and semi-annual report to those addresses shared by two or more accounts. If you wish to receive individual copies of these documents, please call us at (866) 392-0869, or contact your financial institution. We will begin sending you individual copies thirty (30) days after receiving your request.

Many states have unclaimed property rules that provide for transfer to the state (also known as “escheatment”) of unclaimed property under various circumstances. These circumstances include inactivity (e.g., no owner-initiated contact for a certain period), returned mail (e.g., when mail sent to a shareholder is returned by the post office as undeliverable), or a combination of both inactivity and returned mail. If a State Street Fund identifies property as unclaimed, it will attempt to contact the shareholder, but if that attempt is unsuccessful, the account may be considered abandoned and escheated to the state after the passage of a certain period of time (as required by applicable state law).

If you are a resident of the state of Texas, you may designate a representative to receive escheatment notifications by completing and submitting a designation form, which you can find on the website of the Texas Comptroller. Designating such a representative may be beneficial, since Texas law provides that the escheatment period will cease if the repre-

59

sentative, after receiving an escheatment notification regarding your account, communicates knowledge of your location and confirms that you have not abandoned your account. You can mail a completed designation form to the Fund (if you hold shares directly with the Fund) or to your financial intermediary (if you do not hold shares directly with the Fund).

Dividends, Distributions and Tax Considerations

The Funds intend to declare dividends on shares from net investment income daily and pay them as of the last Business Day of each month. Distributions from capital gains, if any, will be made annually in December. Dividends of investment income and capital gain distributions will be paid in additional shares on the reinvestment date unless you have elected to receive them in cash. No interest will accrue on the amounts represented by uncashed distribution checks. If you have elected to receive distributions by check, and the postal or other delivery service is unable to deliver the checks because of an incorrect mailing address, or if a distribution check remains uncashed for six months, the uncashed distribution and all future distributions will be reinvested at the then-current NAV of the Fund.

The following discussion is a summary of some important U.S. federal income tax considerations generally applicable to an investment in a Fund. Your investment in a Fund may have other tax implications. Please consult your tax advisor about federal, state, local, foreign or other tax laws applicable to you. Investors, including non-U.S. investors, may wish to consult the SAI tax section for additional disclosure.

Each Fund has elected to be treated as a regulated investment company and intends each year to qualify and to be eligible to be treated as such. A regulated investment company generally is not subject to tax at the corporate level on income and gains that are timely distributed to shareholders. In order to qualify and be eligible for treatment as a regulated investment company, a Fund must, among other things, satisfy diversification, 90% gross income and distribution requirements. A Fund's failure to qualify as a regulated investment company would result in corporate level taxation, and consequently, a reduction in income available for distribution to shareholders.

Each Fund invests substantially all of its investable assets in a corresponding Portfolio that is treated as a partnership for U.S. federal income tax purposes. Therefore, the nature and character of each Fund's income, gains, losses and deductions generally will be determined at the Portfolio level, and each Fund will be allocated its share of the corresponding Portfolio's income, gains, losses and deductions. As applicable, references in this discussion to income, gains and losses of a Fund will be to income, gains and losses recognized and deductions accruing at the Portfolio level and allocated to or otherwise taken into account by the Fund, and references to assets of a Fund will be to the Fund's allocable share of the assets of the corresponding Portfolio.

For U.S. federal income tax purposes, distributions of investment income are generally taxable to you as ordinary income. Taxes on distributions of capital gains generally are determined by how long the applicable Portfolio or Fund owned (or is deemed to have owned) the investments that generated them, rather than how long you have owned your Fund Shares. Any net short-term gains the Funds distribute will be taxable to you as ordinary income. The Funds generally do not expect to make distributions that are eligible for taxation as long-term capital gains.

Distributions are taxable to you even if they are paid from income or gains earned by a Fund before your investment (and thus were included in the price you paid for your shares). Distributions may also be subject to state and local taxes and are taxable whether you receive them in cash or reinvest them in additional shares. Distributions in excess of a Fund's current and accumulated earnings and profits are treated as a return of capital to the extent of your basis in the applicable Fund's shares, and, in general, as capital gain thereafter.

When the NAV of Fund Shares varies from a shareholder's tax basis in such shares, including when the NAV of such Fund Shares varies from $1.0000 per share, the shareholder generally will realize a gain or loss upon the redemption or other taxable disposition of such Fund Shares. Any such gain generally would be taxable to you as either short-term or long-term capital gain, depending upon how long you held the Fund Shares. The Internal Revenue Service (the “IRS”) has issued final regulations and published guidance that permit a simplified method of accounting for gains and losses realized upon the disposition of money market fund shares. Shareholders should see the SAI for further information.

A Fund's and a Portfolio's income from or proceeds of investments in non-U.S. assets may be subject to non-U.S. with-

60

holding and other taxes. This will decrease the Fund's return on securities subject to such taxes. Tax treaties between certain countries and the U.S. may reduce or eliminate such taxes. Although such taxes will reduce a Fund's taxable income, shareholders generally will not be entitled separately to claim a credit or deduction with respect to foreign taxes incurred by the Portfolio or Fund.

An additional 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates and trusts to the extent their income exceeds certain threshold amounts. Net investment income generally includes for this purpose dividends paid by a Fund and net gains recognized on the redemption of Fund Shares.

If you are not a U.S. person, dividends paid by a Fund that the Fund properly reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends, each as further defined in the SAI, are not subject to withholding of U.S. federal income tax, provided that certain requirements are met. A Fund is permitted, but is not required, to report any part of its dividends as are eligible for such treatment. A Fund's dividends other than those the Fund so reports as capital gain dividends, short-term capital gain dividends, or interest-related dividends generally will be subject to U.S. withholding tax at a 30% rate (or lower applicable treaty rate). See each Fund's SAI for further information.

The U.S. Treasury and IRS generally require a Fund to obtain information sufficient to identify the status of each shareholder under sections 1471-1474 of the Internal Revenue Code of 1986, as amended, and the U.S. Treasury and IRS guidance issued thereunder (collectively, the “Foreign Account Tax Compliance Act” or “FATCA”) or under an applicable intergovernmental agreement between the United States and a foreign government. Please see the SAI for more information on FATCA reporting requirements.

Financial Intermediary Arrangements

Distribution Arrangements and Rule 12b-1 Fees

The Funds have adopted a distribution plan pursuant to Rule 12b-1 under the 1940 Act under which a Fund may compensate SSGA FD (or others) for services in connection with the distribution of a Fund's shares and for services provided to Fund shareholders (the “Plan”). The Plan calls for payments at an annual rate (based on average daily net assets) of 0.05% and 0.10% of each Fund's net assets attributable to its Administration Class shares and Investment Class shares, respectively. Because these fees are paid out of the assets of a Fund attributable to its shares on an ongoing basis, they will increase the cost of your investment and may cost you more over time than paying other types of sales charges. Long-term shareholders of the Fund may pay more in Rule 12b-1 fees than the economic equivalent of the maximum front-end sales charge permitted by the FINRA.

A Fund may pay distribution fees and other amounts described in this Prospectus at a time when shares of that Fund are unavailable for purchase.

Other Payments to Financial Intermediaries

In addition to payments under the Plan described above, the Funds may reimburse SSGA FD or its affiliates for payments made to Financial Intermediaries that provide certain administrative, recordkeeping, and account maintenance services. The amount of the reimbursement and the manner in which it is calculated are reviewed by the Trustees periodically.

Financial Intermediaries are firms that sell shares of mutual funds, including the Funds, and/or provide certain administrative and account maintenance services to mutual fund investors. Financial Intermediaries may include, among others, brokers, financial planners or advisers, banks, retirement plan recordkeepers and insurance companies.

In some cases, a Financial Intermediary may hold its clients' Fund Shares in nominee or street name and may utilize omnibus accounts. Shareholder services provided by a Financial Intermediary may (though they will not necessarily) include, among other things: establishing and maintaining shareholder account registrations; receiving and processing purchase and redemption orders, including aggregated orders and delivering orders to the Fund's transfer agent; processing and mailing trade confirmations, periodic statements, prospectuses, annual reports, semiannual reports, shareholder notices, and other SEC-required communications; capturing and processing tax data; issuing and mailing dividend checks to shareholders who have selected cash distributions; preparing record date shareholder lists for proxy solicitations; and collecting and posting distributions to shareholder accounts.

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The Financial Intermediary is often compensated by SSGA FD or its affiliates for the services it performs and in such cases is typically paid continually over time, during the period when the Financial Intermediary's clients hold investments in the Funds. The amount of continuing compensation paid by SSGA FD or its affiliates to different Financial Intermediaries for distribution and/or shareholder services varies. Any compensation is typically a percentage of the value of the Financial Intermediary's clients' investments in the Funds or a per account fee. The variation in compensation may, but will not necessarily, reflect enhanced or additional services provided by the Financial Intermediary.

If you invest through a Financial Intermediary and meet the eligibility criteria for more than one share class, you should discuss with your Financial Intermediary which share class is appropriate for you. Your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend one share class over another, when you are eligible to invest in more than one share class. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by the Funds or its affiliates with respect to the different share classes offered by the Funds.

SSGA FD and its affiliates (including SSGA FM), at their own expense and out of their own assets, may also provide other compensation to Financial Intermediaries in connection with sales of the Funds' shares or the servicing of shareholders or shareholder accounts. Such compensation may include, but is not limited to, financial assistance to Financial Intermediaries in connection with conferences, sales, or training programs for their employees; seminars for the public; advertising or sales campaigns; or other Financial Intermediary-sponsored special events. In some instances, this compensation may be made available only to certain Financial Intermediaries whose representatives have sold or are expected to sell significant amounts of shares. Dealers may not use sales of the Funds' shares to qualify for this compensation to the extent prohibited by the laws or rules of any state or any self-regulatory agency, such as FINRA.

If payments to Financial Intermediaries by the distributor or adviser for a particular mutual fund complex exceed payments by other mutual fund complexes, your financial adviser and the Financial Intermediary employing him or her may have an incentive to recommend that fund complex over others. Please speak with your financial adviser to learn more about the total amounts paid to your financial adviser and his or her firm by SSGA FD and its affiliates and by sponsors of other mutual funds he or she may recommend to you. You should also consult disclosures made by your Financial Intermediary at the time of purchase.

Third-Party Transactions. The State Street Funds have authorized certain Financial Intermediaries to accept purchase, redemption and exchange orders on the State Street Funds' behalf. Orders received for a State Street Fund by a Financial Intermediary that has been authorized to accept orders on the Fund's behalf (or other Financial Intermediaries designated by the Financial Intermediary) will be deemed accepted by the Fund at the time they are received by the Financial Intermediary and will be priced based on the Fund's next NAV determination as long as the Financial Intermediary transmits the order in good form and in a timely manner to the applicable State Street Fund(s). For the ELR Fund and ILR Fund, the State Street Funds will be the sole party to determine if a trade is received in good order. The Financial Intermediary is responsible for transmitting your orders and associated funds in good form and in a timely manner to the applicable State Street Fund(s). The State Street Funds will not be responsible for delays by the Financial Intermediary in transmitting your orders, including timely transfer of payment, to a Fund.

If you are purchasing, selling, exchanging or holding State Street Fund shares through a program of services offered by a Financial Intermediary, you may be required by the Financial Intermediary to pay additional fees. You should contact the Financial Intermediary for information concerning what additional fees, if any, may be charged.

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Financial Highlights

The financial highlight tables are intended to help you understand each Fund's financial performance   for the past five fiscal years or, if shorter, the period since each class' inception. Certain information reflects the performance results for a single Fund Share. The total returns in the table represent the rate that an investor would have earned (or lost) on an investment in each Fund (assuming reinvestment of all dividends and distributions). This information has been audited by Ernst & Young LLP, the Trust's independent registered public accounting firm, whose report, along with each Fund's financial highlights and financial statements, is included in the annual report to shareholders, which is available upon request. Any references to Notes in these financial highlight tables refer to the “Notes to Financial Statements” section of each Fund's financial statements, and the financial information included in these tables should be read in conjunction with the financial statements incorporated by reference in the SAI.

63

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET ESG LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Institutional Class (a)
	Year Ended 12/31/21		Year Ended 12/31/20		For the Period 12/20/19*- 12/31/19
Net asset value, beginning of period	$1.0002		$1.0000		$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0000(b)		0.0054		0.0006
Net realized and unrealized gain (loss)	—		0.0002		0.0000(b)
Total from investment operations	0.0000(b)		0.0056		0.0006
Distributions to shareholders from:
Net investment income	(0.0001)		(0.0054)		(0.0006)
Net asset value, end of period	$1.0001		$1.0002		$1.0000
Total return (c)	0.04%		0.56%		0.06%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$5,519		$23,023		$50
Ratios to Average Net Assets:
Total expenses	0.19%		0.22%		0.31%(d)
Net expenses	0.11%		0.11%		0.11%(d)
Net investment income (loss)	0.06%		0.12%		1.85%(d)

    

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates of the Fund. Total return for periods of less than one year are not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

64

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET ESG LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS  

Selected data for a share outstanding throughout each period

	Investor Class (a)
	Year Ended 12/31/21		Year Ended 12/31/20		For the Period 12/20/19*- 12/31/19
Net asset value, beginning of period	$1.0002		$1.0000		$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0001		0.0049		0.0006
Net realized and unrealized gain (loss)	—		0.0002		0.0000(b)
Total from investment operations	0.0001		0.0051		0.0006
Distributions to shareholders from:
Net investment income	(0.0001)		(0.0049)		(0.0006)
Total distributions	(0.0001)		(0.0049)		(0.0006)
Net asset value, end of period	$1.0002		$1.0002		$1.0000
Total return (c)	0.01%		0.51%		0.06%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$50		$50		$50
Ratios to Average Net Assets:
Total expenses	0.23%		0.29%		0.36%(d)
Net expenses	0.16%		0.16%		0.16%(d)
Net investment income (loss)	0.00%(e)		0.49%		1.80%(d)

    

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates of the Fund. Total return for periods of less than one year are not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.
(e)	Amount is less than 0.005%.

65

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET ESG LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS  

Selected data for a share outstanding throughout each period

	Premier Class (a)
	Year Ended 12/31/21		Year Ended 12/31/20		For the Period 12/04/2019 *- 12/31/19
Net asset value, beginning of period	$1.0002		$1.0000		$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0000(b)		0.0058		0.0013
Net realized and unrealized gain (loss)	—		0.0002		0.0000(b)
Total from investment operations	0.0000(b)		0.0060		0.0013
Distributions to shareholders from:
Net investment income	(0.0001)		(0.0058)		(0.0013)
Total distributions	(0.0001)		(0.0058)		(0.0013)
Net asset value, end of period	$1.0001		$1.0002		$1.0000
Total return (c)	0.07%		0.60%		0.13%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$1,297,099		$903,258		$881,217
Ratios to Average Net Assets:
Total expenses	0.15%		0.21%		0.23%(d)
Net expenses	0.08%		0.08%		0.08%(d)
Net investment income (loss)	0.08%		0.61%		1.75%(d)

    

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates of the Fund. Total return for periods of less than one year are not annualized. Results represent past performance and are not indicative of future results.
(d)	Annualized.

66

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET ESG LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS  

Selected data for a share outstanding throughout each period

	Opportunity Class (a)
	For the Period 10/28/21*- 12/31/21
Net asset value, beginning of period	$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0000(b)
Net realized and unrealized gain (loss)	—
Total from investment operations	0.0000(b)
Distributions to shareholders from:
Net investment income	(0.0001)
Total distributions	(0.0001)
Net asset value, end of period	$0.9999
Total return (c)	(0.00)%(d)
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$50
Ratios to Average Net Assets:
Total expenses	0.18%(e)
Net expenses	0.12%(e)
Net investment income (loss)	0.02%(e)

    

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates of the Fund. Total return for periods of less than one year are not annualized. Results represent past performance and are not indicative of future results.
(d)	Amount is less than 0.005%.
(e)	Annualized.

67

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS

Selected data for a share outstanding throughout each period

	Institutional Class (a)
	Year Ended 12/31/21		Year Ended 12/31/20		Year Ended 12/31/19		For the Period 7/6/18*- 12/31/18
Net asset value, beginning of period	$1.0003		$1.0002		$1.0001		$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0001		0.0054		0.0217		0.0108
Net realized and unrealized gain (loss)	0.0001		0.0002		0.0009		0.0001
Total from investment operations	0.0002		0.0056		0.0226		0.0109
Distributions to shareholders from:
Net investment income	(0.0002)		(0.0055)		(0.0225)		(0.0108)
Net asset value, end of period	$1.0003		$1.0003		$1.0002		$1.0001
Total return (b)	0.02%		0.56%		2.28%		1.08%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$80,594		$153,757		$183,304		$55
Ratios to Average Net Assets:
Total expenses	0.15%		0.15%		0.16%		0.15%(c)
Net expenses	0.15%		0.15%		0.15%		0.15%(c)
Net investment income (loss)	0.03%		0.57%		2.17%		2.21%(c)

    

*	Commencement of operations.
(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates of the Fund. Total return for periods of less than one year are not annualized. Results represent past performance and are not indicative of future results.
(c)	Annualized.

68

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS  

Selected data for a share outstanding throughout each period

	Administration Class (a)
	Year Ended 12/31/21		Year Ended 12/31/20		Year Ended 12/31/19		Year Ended 12/31/18		Year Ended 12/31/17
Net asset value, beginning of period	$1.0001		$1.0001		$0.9999		$1.0000		$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0000(b)		0.0039		0.0206		0.0174		0.0080
Net realized and unrealized gain (loss)	(0.0001)		—		(0.0001)		(0.0001)		0.0000(b)
Total from investment operations	(0.0001)		0.0039		0.0205		0.0173		0.0080
Distributions to shareholders from:
Net investment income	—		(0.0039)		(0.0203)		(0.0174)		(0.0080)
Net realized gains	—		—		—		—		0.0000(b)
Total distributions	—		(0.0039)		(0.0203)		(0.0174)		(0.0080)
Net asset value, end of period	$1.0000		$1.0001		$1.0001		$0.9999		$1.0000
Total return (c)	(0.01)%		0.39%		2.07%		1.75%		0.80%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$663,480		$567,550		$613,074		$956,750		$831,606
Ratios to Average Net Assets:
Total expenses	0.37%		0.37%		0.38%		0.37%		0.37%
Net expenses	0.17%		0.32%		0.37%		0.37%		0.37%
Net investment income (loss)	0.00%(d)		0.43%		2.06%		1.74%		0.80%

    

(a)	The per share amounts and percentages include the Fund's proportionate share of income and expenses of the affiliated Portfolio.
(b)	Amount is less than $0.00005 per share.
(c)	Total return is calculated assuming a purchase of shares at net asset value on the first day and a sale at net asset value on the last day of each period reported. Distributions are assumed, for the purpose of this calculation, to be reinvested at net asset value per share on the respective payment dates of the Fund. Total return for periods of less than one year are not annualized. Results represent past performance and are not indicative of future results.
(d)	Amount is less than 0.005%.

69

STATE STREET INSTITUTIONAL INVESTMENT TRUST

STATE STREET INSTITUTIONAL LIQUID RESERVES FUND

FINANCIAL HIGHLIGHTS  

Selected data for a share outstanding throughout each period

	Investment Class (a)
	Year Ended 12/31/21		Year Ended 12/31/20		Year Ended 12/31/19		Year Ended 12/31/18		Year Ended 12/31/17
Net asset value, beginning of period	$1.0002		$1.0002		$1.0000		$0.9999		$1.0000
Income (loss) from investment operations:
Net investment income (loss)	0.0000		0.0036		0.0201		0.0164		0.0070
Net realized and unrealized gain (loss)	—		—		(0.0003)		0.0001		(0.0001)
Total from investment operations	0.0000(b)		0.0036		0.0198		0.0165		0.0069
Distributions to shareholders from:
Net investment income	—		(0.0036)		(0.0196)		(0.0164)		(0.0070)
Net realized gains	—		—		—		—		0.0000(b)
Total distributions	—		(0.0036)		(0.0196)		(0.0164)		(0.0070)
Net asset value, end of period	$1.0002		$1.0002		$1.0002		$1.0000		$0.9999
Total return (c)	0.00%(d)		0.37%		1.99%		1.67%		0.69%
Ratios and Supplemental Data:
Net assets, end of period (in 000s)	$6		$6		$12		$23		$5,547
Ratios to Average Net Assets:
Total expenses	0.48%		0.45%		0.47%		0.47%		0.47%
Net expenses	0.17%		0.35%		0.45%		0.47%		0.47%
Net investment income (loss)	(0.03)%		0.38%		2.01%		1.18%		0.70%