# EDGAR Filing Document

**Accession Number:** 0001107414
**File Stem:** 0001193125-26-191825
**Filing Date:** 2026-4
**Character Count:** 37802
**Document Hash:** 069ddc71e6e6a3d858383fbd1743d2f0
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-191825.hdr.sgml**: 20260429

**ACCESSION NUMBER**: 0001193125-26-191825

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 4

**FILED AS OF DATE**: 20260429

**DATE AS OF CHANGE**: 20260429

**EFFECTIVENESS DATE**: 20260429

**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:** 26916529

**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 Aggregate Bond Index Fund (Series ID: S000010699)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000136668 | Class A      | SSFCX           |
| C000136669 | Class K      | SSFEX           |
| C000136670 | Class I      | SSFDX           |

![](g314169ssinst_xylogo.gif)

**State Street Aggregate Bond Index Fund**

**Class A (SSFCX) Class I (SSFDX) Class K (SSFEX)** 

**Summary Prospectus – April 30, 2026** 

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| |
|:---|
| &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 (800) 647-7327, 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> Iron Street, Boston, Massachusetts 02210. The fund's current prospectus and statement of additional information <br> are incorporated by reference into this summary prospectus.<br>|

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**Investment Objective**

The State Street Aggregate Bond Index Fund (the "Aggregate Bond Index Fund" or the "Fund") seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of an index that tracks the U.S. dollar denominated investment grade bond market over the long term.

**Fees and Expenses of the Fund**

The tables below describe 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 tables and examples below.** You may qualify for sales charge discounts on purchases of Class A shares if you agree to invest in the future, or if you and your family currently invest, at least $100,000 in State Street Funds that offer Class A shares. More information about these and other discounts is available from your financial intermediary ("Financial Intermediary") and in Choosing a Share Class – Reducing Your Class A Sales Charge on page 63 of the Fund's Prospectus. The expenses shown in the table and the Example reflect the expenses of both the Fund and the Fund's proportionate share of the expenses of State Street Aggregate Bond Index Portfolio (the "Aggregate Bond Index Portfolio" or sometimes referred to in context as the "Portfolio").

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

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| | | | |
|:---|:---|:---|:---|
|  | **Class A** | **Class I** | **Class K** |
| Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price) | 3.75% |  |  |
| &nbsp;&nbsp;&nbsp; Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the sale proceeds or the <br> original offering price)<br>| &nbsp;&nbsp; None<sup>1</sup> <br>|  |  |

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![](g314169ssim.gif)

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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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| | | | |
|:---|:---|:---|:---|
|  | **Class A** | **Class I** | **Class K** |
| Management Fee | &nbsp;&nbsp; 0.025% | &nbsp;&nbsp; 0.025% | &nbsp;&nbsp; 0.025% |
| Distribution and/or Shareholder Service (12b-1) Fees | &nbsp;&nbsp; 0.250% | &nbsp;&nbsp; 0.000% | &nbsp;&nbsp; 0.000% |
| Other Expenses<sup>2</sup> <br>| &nbsp;&nbsp; 0.298% | &nbsp;&nbsp; 0.298% | &nbsp;&nbsp; 0.098% |
| Total Annual Fund Operating Expenses | &nbsp;&nbsp; 0.573% | &nbsp;&nbsp; 0.323% | &nbsp;&nbsp; 0.123% |
| Less Fee Waivers and/or Expense Reimbursements<sup>3,</sup><sup>4</sup> <br>| &nbsp;&nbsp; (0.098%) | &nbsp;&nbsp; (0.098%) | &nbsp;&nbsp; (0.098%) |
| Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements | &nbsp;&nbsp; 0.475% | &nbsp;&nbsp; 0.225% | &nbsp;&nbsp; 0.025% |

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<sup>1</sup>

A contingent deferred sales charge ("CDSC") of 1.00% may be assessed on redemptions of Class A shares made within 18 months after purchase where no initial sales charge was paid at the time of purchase as part of an investment of $1,000,000 or more.

<sup>2</sup>

Other Expenses have been restated to reflect current fees.

<sup>3</sup>

The Fund's investment adviser, SSGA Funds Management, Inc. (the "Adviser" or "SSGA FM"), is contractually obligated until April 30, 2027, separately with respect to each of the Fund and the Portfolio, (i) to waive up to the full amount of the advisory fee payable by the Fund or the Portfolio, and/or (ii) to reimburse the Fund or the Portfolio to the extent that Total Annual Fund Operating Expenses (exclusive of non-recurring account fees, interest, taxes, extraordinary expenses, and distribution, shareholder servicing, and sub-transfer agency fees) exceed 0.025% of the Fund's or the Portfolio's average daily net assets on an annual basis (for avoidance of doubt, the waiver and/or reimbursement is inclusive of all the allocation of expenses from the Portfolio). This waiver and/or reimbursement may not be terminated prior to April 30, 2027 except with approval of the Fund's/Portfolio's Board of Trustees.

<sup>4</sup>

SSGA FM is contractually obligated to waive up to the portion of the management fee and/or expenses attributable to acquired fund fees and expenses in connection with the Portfolio's investments in acquired funds held for other than cash management purposes. This fee waiver and/or expense reimbursement may only be terminated with approval of the Fund's/Portfolio's Board of Trustees.

**Example:**

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated, 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. The calculation of costs for the one-year period takes into account the effect of any current contractual fee waivers and/or reimbursements; and the calculation of costs for the remaining periods takes such fee waivers and/or reimbursements into account only for the first year of each such period. 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** | **5 years** | **10 years** |
| Class A | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $422 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $542 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $674 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $1056 |
| Class I | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $23 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $94 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $172 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $400 |
| Class K | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $3 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $30 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $59 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; $148 |

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**Portfolio Turnover:**

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its portfolio). As a shareholder of the Aggregate Bond Index Portfolio, the Fund bears its ratable share of the transaction costs associated with the portfolio turnover of the Portfolio. A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund Shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 17% of the average value of its portfolio.

**Principal Investment Strategies**

The Fund is an "index" fund that seeks to track, before fees and expenses, the total return performance of the Bloomberg U.S. Aggregate Bond Index (the "U.S. Aggregate Bond Index" or sometimes referred to in context as the "Index") over the long term. As an "index" fund, the Fund is not managed according to traditional methods of "active" investment management, which involve the buying and selling of securities based upon economic, financial and market analysis and investment judgment.

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In seeking to track the performance of the Index, the Fund employs a sampling strategy, which means that the Fund will not typically purchase all of the securities represented in the Index. Instead, the Fund may purchase a subset of the securities in the Index, or securities the Adviser considers to be comparable to securities in the Index, in an effort to hold a portfolio of securities with generally the same risk and return characteristics of the Index. The number of holdings in the Fund will be based on a number of factors, including asset size of the Fund. SSGA Funds Management, Inc. ("SSGA FM" or the "Adviser"), the investment adviser to the Fund, generally expects the Fund to hold fewer than the total number of securities in the Index, but reserves the right to hold as many securities as it believes necessary to achieve the Fund's investment objective.

Under normal circumstances, the Fund generally invests substantially all, but at least 80%, of its net assets (plus borrowings, if any) in securities comprising the Index or in securities that the Adviser determines have economic characteristics that are comparable to the economic characteristics of securities that comprise the Index. The notional value of the Fund's investments in derivatives or other synthetic instruments that provide exposures comparable, in the judgment of the Adviser, to investments in the Index may be counted toward satisfaction of this 80% policy. The Fund will provide shareholders with at least sixty (60) days' notice prior to any change in this 80% investment policy. The Fund may also invest in other debt securities, cash and cash equivalents or money market instruments, such as repurchase agreements and money market funds (including money market funds advised by the Adviser).

The Fund may at times purchase or sell futures contracts on fixed-income securities, or options on those futures, in lieu of investing directly in fixed-income securities themselves. The Fund may also purchase or sell futures contracts and related options on the Index (or other fixed-income securities indices). The Fund might do so, for example, in order to adjust the interest-rate sensitivity of the Fund to bring the characteristics of the Fund more closely in line with those of the Index. It might also do so to increase its investment exposure pending investment of cash in bonds or other investments or to reduce its investment exposure in situations where it intends to sell a portion of the securities in its portfolio but the sale has not yet been completed. The Fund may also enter into other derivatives transactions, including the use of options or swap transactions, in lieu of investing directly in the stocks making up the Index. The Fund may, to the extent permitted by applicable law, invest in shares of other mutual funds whose investment objectives and policies are similar to those of the Fund (including funds advised by the Adviser).

The Index is designed to measure the performance of the U.S. dollar denominated investment grade bond market, which includes investment grade (must be Baa3/BBB-/BBB- or higher using the middle rating of Moody's Investors Service, Inc., Standard & Poor's, and Fitch Inc.) government bonds, investment grade corporate bonds, mortgage pass-through securities, commercial mortgage backed securities and other asset backed securities that are publicly for sale in the United States. The securities in the Index must have at least 1 year remaining to maturity and must have $300 million or more of outstanding face value. Asset backed securities must have a minimum deal size of $500 million and a minimum tranche size of $25 million. For commercial mortgage backed securities, the original aggregate transaction must have a minimum deal size of $500 million, and a minimum tranche size of $25 million; the aggregate outstanding transaction sizes must be at least $300 million to remain in the Index. In addition, the securities must be U.S. dollar denominated, fixed rate, non-convertible, and taxable. Certain types of securities, such as flower bonds, targeted investor notes, and state and local government series bonds are excluded from the Index. Also excluded from the Index are structured notes with embedded swaps or other special features, private placements and floating rate securities. The Index is market capitalization weighted and the securities in the Index are updated on the last business day of each month. It is not possible to invest directly in the Index.

The Fund expects typically to invest a significant portion of its assets in U.S. agency mortgage pass-through securities up to a total weight that is comparable to that of the Index. Most transactions in mortgage pass-through securities occur through standardized contracts for future delivery in which the exact mortgage pools to be delivered are not specified until a few days prior to settlement, referred to as a "to-be-announced transaction" or "TBA Transaction." In a TBA Transaction, the buyer and seller agree upon general trade parameters such as agency, settlement date, par amount and price. The actual pools delivered generally are determined two days prior to the settlement date; however, it is not anticipated that the Fund will receive pools, but instead will participate in rolling TBA Transactions. The Fund expects to enter into such contracts on a regular basis.

The Fund seeks to achieve its investment objective by investing substantially all of its investable assets in the Aggregate Bond Index 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.

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The Index is sponsored by Bloomberg Index Services Limited (the "Index Provider") which is not affiliated with the Fund or the Adviser. The Index Provider determines the composition of the Index, relative weightings of the securities in the Index and publishes information regarding the market value of the Index.

**Principal Risks**

The Fund is subject to the following principal risks. You could lose money by investing in the Fund. 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. **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 may not achieve its investment objective. The Fund is not intended to be a complete investment program, but rather is intended for investment as part of a diversified investment portfolio. Investors should consult their own advisers as to the role of the Fund in their overall investment programs.

***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.

***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.

***Mortgage-Related and Other Asset-Backed Securities Risk:*** 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. During periods of falling interest rates, mortgage- and asset-backed securities may be called or prepaid, which may result in the Fund having to reinvest proceeds in other investments at a lower interest rate. During periods of rising interest rates, the average life of mortgage- and asset-backed securities may extend, which may lock in a below-market interest rate, increase the security's duration and interest rate sensitivity, and reduce the value of the security. Enforcing rights against the underlying assets or collateral may be difficult, and the underlying assets or collateral may be insufficient if the issuer defaults.

***U.S. Government Securities Risk:*** Certain U.S. government securities 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

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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, are not supported by the full faith and credit of the U.S. government, and involve increased credit risks.

***Indexing Strategy/Index Tracking Risk:*** The Fund is managed with an indexing investment strategy, attempting to track the performance of an unmanaged index of securities, regardless of the current or projected performance of the Index or of the actual securities comprising the Index. This differs from an actively-managed fund, which typically seeks to outperform a benchmark index. As a result, the Fund's performance may be less favorable than that of a portfolio managed using an active investment strategy. The structure and composition of the Index will affect the performance, volatility, and risk of the Index and, consequently, the performance, volatility, and risk of the Fund. While the Adviser seeks to track the performance of the Index (*i.e.*, achieve a high degree of correlation with the Index), the Fund's return may not match the return of the Index. The Fund incurs a number of operating expenses not applicable to the Index, and may incur costs in buying and selling securities. In addition, the Fund may not be fully invested at times, generally as a result of cash flows into or out of the Fund or reserves of cash held by the Fund to meet redemptions. The Adviser may attempt to replicate the Index return by investing in fewer than all of the securities in the Index, or in some securities not included in the Index, potentially increasing the risk of divergence between the Fund's return and that of the Index.

***Counterparty Risk:*** The Fund will be subject to credit risk with respect to the counterparties with which the Fund enters into derivatives contracts, repurchase agreements, reverse repurchase agreements, and other transactions. If a counterparty fails to meet its contractual obligations, the Fund may be unable to terminate or realize any gain on the investment or transaction, or to recover collateral posted to the counterparty, resulting in a loss to the Fund. If the Fund holds collateral posted by its counterparty, it may be delayed or prevented from realizing on the collateral in the event of a bankruptcy or insolvency proceeding relating to the counterparty.

***Derivatives Risk:*** Derivative transactions can create investment leverage and may have significant volatility. It is possible that a derivative transaction will result in a much greater loss than the principal amount invested, that changes in the value of a derivative transaction may not correlate perfectly with the underlying asset, and that the Fund may not be able to close out a derivative transaction at a favorable time or price. The counterparty to a derivatives contract may be unable or unwilling to make timely settlement payments, return the Fund's margin, or otherwise honor its obligations. A derivatives transaction may not behave in the manner anticipated by the Adviser or may not have the effect on the Fund anticipated by the Adviser.

***Income Risk:*** The Fund's income may decline due to falling interest rates or other factors. Issuers of securities held by the 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 the Fund is prepaid, the Fund may have to reinvest the prepayment in other obligations paying income at lower rates.

***Large Transactions Risk:*** To the extent a large proportion of the shares of the Portfolio or 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 or Fund shares in large amounts rapidly or unexpectedly, including as a result of an asset allocation decision made by the Adviser. In addition, a large number of shareholders collectively may purchase or redeem Portfolio or Fund shares in large amounts rapidly or unexpectedly (collectively, such transactions are referred to as "large shareholder transactions"). Large shareholder transactions could adversely affect the ability of the Portfolio or Fund to conduct its investment program.

***Liquidity Risk:*** Lack of a ready market, stressed market conditions, or restrictions on resale may limit the ability of the Fund to sell a security at an advantageous time or price or at all. Illiquid investments may trade at a discount from comparable, more liquid investments and may be subject to wide fluctuations in market value. Illiquidity of the Fund's holdings may also limit the ability of the Fund to obtain cash to meet redemptions on a timely basis. In addition, the Fund, due to limitations on investments in any illiquid investments and/or the difficulty in purchasing and selling such investments, may be unable to achieve its desired level of exposure to a certain market or sector.

***Master/Feeder Structure Risk:*** The Fund pursues its objective by investing substantially all of its assets in another pooled investment vehicle (a "master fund"). The ability of the Fund to meet its investment objective is directly related to the ability of the master fund to meet its investment objective. The Adviser serves as investment adviser to the master fund, leading to potential conflicts of interest. The Fund will bear its pro rata portion of the expenses incurred

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by the master fund. Substantial redemptions by other investors in a master fund may affect the master fund's investment program adversely and limit the ability of the master fund to achieve its objective.

***Risk of Investment in Other Pools:*** If the Fund invests in another pooled investment vehicle, it is exposed to the risk that the other pool will not perform as expected and is exposed indirectly to all of the risks applicable to an investment in such other pool. The investment policies of the other pool may not be the same as those of the Fund; as a result, an investment in the other pool may be subject to additional or different risks than those to which the Fund is typically subject. The 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. 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 the Fund does so.

***Unconstrained Sector Risk:*** The Fund may invest a substantial portion of its assets within one or more economic sectors or industries, which may change from time to time. Greater investment focus on one or more sectors or industries increases the potential for volatility and the risk that events negatively affecting such sectors or industries could reduce returns, potentially causing the value of the Fund's Shares to decrease, perhaps significantly.

***Valuation Risk:*** Certain portfolio holdings may be valued on the basis of factors other than market quotations. This may occur more often in times of market turmoil or reduced liquidity. There are multiple methods that can be used to value a portfolio holding when market quotations are not readily available. The value established for any portfolio holding at a point in time might differ from what would be produced using a different methodology or if it had been priced using market quotations. Portfolio holdings that are valued using techniques other than market quotations, including "fair valued" securities, may be subject to greater fluctuation in their valuations from one day to the next than if market quotations were used. In addition, there is no assurance that the Fund could sell or close out a portfolio position for the value established for it at any time, and it is possible that the Fund would incur a loss because a portfolio position is sold or closed out at a discount to the valuation established by the Fund at that time. Investors who purchase or redeem Fund Shares on days when the Fund is holding fair-valued investments may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the Fund had not fair-valued the holding(s) or had used a different valuation methodology.

***When-Issued, TBA and Delayed Delivery Securities Risk:*** The Fund may purchase securities on a when-issued, to-be-announced ("TBA") or delayed delivery basis and may purchase securities on a forward commitment basis. The purchase price of the securities is typically fixed at the time of the commitment, but delivery and payment can take place a month or more after the date of the commitment. At the time of delivery of the securities, the value may be more or less than the purchase or sale price. Purchase of securities on a when-issued, TBA, delayed delivery, or forward commitment basis may give rise to investment leverage, and may result in increased volatility of the Fund's net asset value. Default by, or bankruptcy of, a counterparty to a when-issued, TBA or delayed delivery transaction would expose the Fund to possible losses because of an adverse market action, expenses or delays in connection with the purchase or sale of the pools specified in such transaction. The Financial Industry Regulatory Authority, Inc. ("FINRA") imposes mandatory margin requirements for certain types of when-issued, delayed delivery or forward commitment transactions (including TBA transactions), with limited exceptions. Such transactions require mandatory collateralization which may increase the cost of such transactions and impose added operational complexity.

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**Performance**

The bar chart and table below provide some indication of the risks of investing in the Fund by illustrating the variability of the Fund's returns from year-to-year and by showing how the Fund's average annual returns for the periods indicated compared with those of the Index. The bar chart shows how the Class A shares' returns have varied for each full calendar year shown. The effect of sales charges, applicable to Class A shares only, is not reflected in the bar chart; if these amounts were reflected, returns would be lower. The Fund's past performance does not necessarily indicate how the Fund will perform in the future. Current performance information for the Fund is available toll free by calling (800) 997-7327 or by visiting our website at <u>www.statestreet.com/im</u>.

**Annual Total Returns** (years ended 12/31)

![](g314169imgd19ffb951.jpg)

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| | | |
|:---|:---|:---|
|  | **Returns** | **Quarter/Year** |
| **Highest Quarterly Return** | 6.58% | Q4 2023 |
| **Lowest Quarterly Return** | -6.08% | Q1 2022 |

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**Average Annual Total Returns** (for periods ended 12/31/25)

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. After-tax returns depend on an investor's tax situation and may differ from those shown, and after-tax returns are not relevant to investors who hold their shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts ("IRAs"). After tax returns are shown only for Class A and after tax returns will vary for other share classes. Except for differences in returns resulting from differences in fees, expenses, and sales charges (as applicable), all share classes would have substantially similar returns because all share classes invest in the same portfolio of securities.

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| | | | |
|:---|:---|:---|:---|
|  | **One**<br> **Year**<br>| **Five**<br> **Years**<br>| **Ten**<br> **Years**<br>|
| Class A  |  |  |  |
| Return Before Taxes  | &nbsp;&nbsp;&nbsp;&nbsp; 2.72<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; -1.61<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.13<br> %<br>|
| Return After Taxes on Distributions  | &nbsp;&nbsp;&nbsp;&nbsp; 1.21<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; -2.72<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.10<br> %<br>|
| Return After Taxes on Distributions and Sale of Fund Shares  | &nbsp;&nbsp;&nbsp;&nbsp; 1.59<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; -1.66<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; 0.44<br> %<br>|
| Class I Returns Before Taxes  | &nbsp;&nbsp;&nbsp;&nbsp; 7.15<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; -0.56<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.82<br> %<br>|
| Class K Returns Before Taxes  | &nbsp;&nbsp;&nbsp;&nbsp; 7.15<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; -0.44<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; 1.91<br> %<br>|
| Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses or taxes) | &nbsp;&nbsp;&nbsp;&nbsp; 7.30<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; -0.36<br> %<br>| &nbsp;&nbsp;&nbsp;&nbsp; 2.01<br> %<br>|

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The Fund will make updated performance information, including its current net asset value, available at the Fund's website: <u>www.statestreet.com/im</u>.

**Investment Adviser**

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

The professionals primarily responsible for the day-to-day management of the Portfolio and the Fund are Marc DiCosimo, Michael Przygoda and Read Burns. They have served as portfolio managers of the Fund and the Portfolio since 2014, 2023 and 2026, respectively.

Marc DiCosimo, CFA, is a Vice President of the Adviser and a Senior Portfolio Manager in the Fixed Income Beta Solutions Team. He joined the Adviser in 2013.

Michael Przygoda, CFA, is a Vice President of the Adviser and a Portfolio Manager in the Fixed Income Beta Solutions Team. He joined the Adviser in 2006.

Read Burns is a Vice President of the Adviser and a Portfolio Manager in the Fixed Income Beta Solutions Team. He joined the Adviser in 2012.

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**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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| | |
|:---|:---|
| **Class A** |  |
| To establish an account | $2000 |
| To add to an existing account |  |
| **Class I** |  |
| To establish an account |  |
| To add to an existing account |  |
| **Class K** |  |
| To establish an account |  |
| 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.

*Written Requests and Wire Transfers*. 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

<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 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 and/or capital gains, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or IRA. 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.

SSITABSUMPRO

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