# EDGAR Filing Document

**Accession Number:** 0001107414
**File Stem:** 0001193125-26-108457
**Filing Date:** 2026-3
**Character Count:** 19422
**Document Hash:** 1bea34ff17fd0936c4003733ddb36ac7
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-108457.hdr.sgml**: 20260316

**ACCESSION NUMBER**: 0001193125-26-108457

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20260316

**DATE AS OF CHANGE**: 20260316

**EFFECTIVENESS DATE**: 20260316

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** STATE STREET INSTITUTIONAL INVESTMENT TRUST
- **CENTRAL INDEX KEY:** 0001107414

**ORGANIZATION NAME:**
- **EIN:** 046910804
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-30810
- **FILM NUMBER:** 26757380

**BUSINESS ADDRESS:**
- **STREET 1:** ONE CONGRESS STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02114
- **BUSINESS PHONE:** 6176643920

**MAIL ADDRESS:**
- **STREET 1:** ONE CONGRESS STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02114

## Series and Classes Contracts Data

### State Street Stablecoin Reserves Money Market Fund (Series ID: S000101071)

| Class ID   | Class Name      | Ticker Symbol   |
|:---|:---|:---|
| C000271008 | Preferred Class | SSRXX           |
| C000271009 | Capital Class   | SSCXX           |

![](g14628ssinst_xylogo.gif)

**State Street Stablecoin Reserves Money Market Fund**

**Preferred Class (SSRXX) Capital Class (SSCXX)** 

**Summary Prospectus – March 6, 2026** 

---

| |
|:---|
| &nbsp;&nbsp;&nbsp; Before you invest, you may want to review the fund's prospectus, which contains more information about the fund <br> and its risks. You may find the fund's prospectus and other information about the fund online at:<br>|
| &nbsp;&nbsp;&nbsp; www.statestreet.com/im |
| &nbsp;&nbsp;&nbsp; You may also get this information at no cost by calling (866) 392-0869, by sending an e-mail request to <br> Fund_Inquiry@ssga.com, or by writing to the fund, c/o State Street Global Advisors Funds Distributors, LLC, One <br> Congress Street, Boston, Massachusetts 02114. The fund's current prospectus and statement of additional <br> information are incorporated by reference into this summary prospectus.<br>|

---

**Investment Objective**

The investment objective of State Street Stablecoin Reserves Money Market Fund (the "Stablecoin Fund" or sometimes referred to in context as the "Fund") is to seek a high level of current income consistent with preserving principal and liquidity and the maintenance of a stable $1.00 per share net asset value ("NAV").

**Fees and Expenses of the Fund**

The table below describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund ("Fund Shares"). **You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and Example below.**

**Shareholder Fees** (fees paid directly from your investment)

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| |
|:---|
| Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) |
| Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the original offering price) |

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**Annual Fund Operating Expenses** (expenses that you pay each year as a percentage of the value of your investment)

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| | | |
|:---|:---|:---|
|  | **Preferred Class** | **Capital Class** |
| Management Fee | &nbsp;&nbsp; 0.05% | &nbsp;&nbsp; 0.05% |
| Distribution and/or Shareholder Service (12b-1) Fees | &nbsp;&nbsp; 0.00% | &nbsp;&nbsp; 0.00% |
| Other Expenses |  |  |
| &nbsp;&nbsp;&nbsp; Operations and Administration Fee <sup>1</sup> <br>| &nbsp;&nbsp; 0.07% | &nbsp;&nbsp; 0.13% |
| Total Annual Fund Operating Expenses | &nbsp;&nbsp; 0.12% | &nbsp;&nbsp; 0.18% |

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<sup>1</sup>

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

![](g14628ssim.gif)

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**Example:**

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated, and then sell or hold all of your Fund Shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

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| | | |
|:---|:---|:---|
|  | **1 year** | **3 years** |
| Preferred | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $12 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $39 |
| Capital | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $18 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $58 |

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**Principal Investment Strategies**

The Fund, which is advised by SSGA Funds Management, Inc. ("SSGA FM" or the "Advisor"), invests in assets in which payment stablecoin issuers are permitted to invest in under a U.S. law enacted in July 2025 designed to establish a framework of these issuers and any regulation adopted thereunder (the "GENIUS Act") ("eligible investments"). These eligible investments include U.S. Treasury bills, notes and bonds ("U.S. Treasury Obligations") with a remaining maturity of 93 days or less or issued with a maturity of 93 days or less, as well as repurchase agreements secured by U.S. Treasury Obligations. The Fund may invest in any other assets that qualify as eligible investments under the GENIUS Act (and any regulations thereunder) and that are permitted under Rule 2a-7 for a government money market fund. The Fund does not invest in stablecoins. 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 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. However, due to its investment strategy, the Fund does not intend to invest in securities with a remaining maturity of more than 93 days and therefore expects to have a weighted average portfolio life significantly less than 120 days.

The Fund is a "government money market fund," so it will invest at least 99.5% of its total assets in cash, government securities, and/or repurchase agreements that are collateralized fully. Government money market funds are exempt from requirements that permit and, under certain circumstances, require money market funds to impose a "liquidity fee" on redemptions. As a "government money market fund," the Fund values its securities using the amortized cost method. The Fund will seek to maintain a stable value of $1.00 per share, however it cannot guarantee it will do so.

**Principal Risks**

The Fund is subject to the following risks. You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. **An investment in the Fund is subject to investment risks, including possible loss of principal, is not a deposit in a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation ("FDIC") or any other government agency.** The Fund's sponsor is not required to reimburse the Fund for losses, and you should not expect that the sponsor will provide financial support to the Fund at any time, including during periods of market stress. Certain risks relating to instruments and strategies used in the management of the Fund are placed first. The significance of any specific risk to an investment in the Fund will vary over time, depending on the composition of the Fund's portfolio, market conditions, and other factors. You should read all of the risk information presented below carefully, because any one or more of these risks may result in losses to the Fund.

***Money Market Fund Risk:*** 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.

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***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. 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 the Fund's fixed income securities to decrease, an adverse impact on the liquidity of the Fund's fixed income securities, and increased volatility of the fixed income markets. During periods when interest rates are at low levels, the Fund's yield can be low, and the Fund may have a negative yield (i.e., it may lose money on an operating basis). To the extent that interest rates fall, certain underlying obligations may be paid off substantially faster than originally anticipated. 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 the 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. High levels of inflation and/or a significantly changing interest rate environment can lead to heightened levels of volatility and reduced liquidity.

***U.S. Treasury Obligations Risk:*** U.S. Treasury obligations may differ from other fixed income 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 the Fund's U.S. Treasury obligations to decline.

***Repurchase Agreement Risk:*** Repurchase agreements may be viewed as loans made by the Fund, which are collateralized by the securities subject to repurchase. If the Fund's counterparty should default on its obligations and the Fund is delayed or prevented from recovering the collateral, or if the value of the collateral is insufficient, the Fund may realize a loss.

***Counterparty Risk:*** The Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into repurchase agreements and other transactions. If a counterparty fails to meet its contractual obligations, the 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.

***Large Transactions Risk:*** To the extent a large proportion of the shares of the Fund are held by a small number of shareholders (or a single shareholder), including funds or accounts over which the Adviser has investment discretion, the Fund is subject to the risk that these shareholders 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 the Fund to conduct its investment program.

***Market Risk:*** The 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, inflation, changes in the actual or perceived creditworthiness of issuers, and general market liquidity. The Fund is subject to the risk that geopolitical events will disrupt securities markets and adversely affect global economies and markets. Local, regional or global events such as war, military conflicts, acts of terrorism, trade policy changes or disputes, the threat or actual imposition of tariffs, natural disasters, the spread of infectious illness or other public health issues, or other events could have a significant impact on the Fund and its investments.

***Interest Rate Risk:*** Interest rate risk is the risk that debt securities will decline in value because of increases in interest rates. The value of a security with a longer duration will be more sensitive to changes in interest rates than a similar security with a shorter duration. 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.

***Rapid Changes in Interest Rates Risk:*** Rapid changes in interest rates may cause significant requests to redeem Fund Shares, and possibly cause the Fund to sell portfolio securities at a loss to satisfy those requests.

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***Stablecoin Issuer Reserves Risk:*** Fund Shares are expected to be held primarily by one or more stablecoin issuers as all or a portion of the reserve assets that back the stablecoins issued to their customers. Although the Fund does not invest in stablecoins or stablecoin issuers, the assets of the Fund are expected to fluctuate depending on the creation (minting) of additional stablecoins or the redemption (burning) of outstanding stablecoins. Stablecoins are relatively new and stablecoins or other digital assets that stablecoins may be used to purchase or sell may face periods of uncertainty and volatility that result in the potential for rapid or unexpected requests by one or more stablecoin issuers to redeem or purchase Fund Shares. Because the Fund intends to invest only in eligible investments, the Fund's yield may be lower than other money market funds that are permitted to invest in a wider universe of investments.

***Stable Share Price Risk:*** 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.

***Variable and Floating Rate Securities Risk:*** During periods of increasing interest rates, changes in the coupon rates of variable or floating rate securities 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.

***Focused Investment Risk:*** To the extent the Fund invests a large percentage of its assets in securities within the same country, state, region, or economic sector its investment strategy could result in more risk or greater volatility in returns than if the Fund's investments were less focused.

**Fund Performance**

<br>The Fund had not commenced operations as of the date of this Prospectus. Once the Fund has completed a full calendar year of operations, a bar chart and table will be included that will provide some indication of the risks of investing in the Fund by showing the variability of the Fund's returns based on net assets. When available, updated performance information may be obtained by calling 1-866-787-2257 or visiting the Fund's website: <u>www.statestreet.com/im</u>.

**Investment Adviser**

SSGA FM serves as the investment adviser to the Fund. The Adviser and certain other affiliates of State Street Corporation make up State Street Investment Management.

**Purchase and Sale of Fund Shares**

<u>Purchase Minimums</u>

The Fund's initial and subsequent investment minimums generally are as follows, although the Fund may reduce or waive the minimums in some cases.

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| | | |
|:---|:---|:---|
|  | Preferred Class | Capital Class |
| To establish an account | $250000000 | $15000000 |
| To add to an existing account |  |  |

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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:

<u>By Mail:</u>

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

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<u>By Overnight/Registered, Express, Certified Mail:</u>

State Street Funds <br>801 Pennsylvania Avenue, Suite 219737 <br>Kansas City, MO 64105-1307

<u>By Telephone:</u>

For wire transfer instructions, please call (866) 392-0869 between 8:00 a.m. and 6:00 p.m. Eastern time. Redemptions by telephone are permitted only if you previously have been authorized for these transactions.

<u>By Intermediary:</u>

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 SS&C GIDS, Inc. at (877) 332-6207 or via email at nsccresearch@dstsystems.com with questions.

**Tax Information**

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.

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