# EDGAR Filing Document

**Accession Number:** 0000225322
**File Stem:** 0000225322-25-000247
**Filing Date:** 2025-7
**Character Count:** 17201
**Document Hash:** b82076b8dac8a5b3ed158c84b25810f8
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000225322-25-000247.hdr.sgml**: 20250729

**ACCESSION NUMBER**: 0000225322-25-000247

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20250729

**DATE AS OF CHANGE**: 20250729

**EFFECTIVENESS DATE**: 20250729

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** FIDELITY SUMMER STREET TRUST
- **CENTRAL INDEX KEY:** 0000225322

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 0430

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 002-58542
- **FILM NUMBER:** 251158873

**BUSINESS ADDRESS:**
- **STREET 1:** 245 SUMMER STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210
- **BUSINESS PHONE:** 617-563-7000

**MAIL ADDRESS:**
- **STREET 1:** 245 SUMMER STREET
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02210

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FIDELITY HIGH INCOME FUND
- **DATE OF NAME CHANGE:** 19890309

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FIDELITY AGGRESSIVE INCOME FUND
- **DATE OF NAME CHANGE:** 19810205

## Series and Classes Contracts Data

### Fidelity SAI Sustainable U.S. Equity Fund (Series ID: S000075899)

| Class ID   | Class Name                                | Ticker Symbol   |
|:---|:---|:---|
| C000235240 | Fidelity SAI Sustainable U.S. Equity Fund | FIDEX           |

**<u>Fund</u>**<u>/Ticker</u>

**Fidelity® SAI Sustainable U.S. Equity Fund**/FIDEX

Offered exclusively to certain clients of the Adviser, or its affiliates, including Strategic Advisers LLC (Strategic Advisers) - not available for sale to the general public. Fidelity® SAI is a product name of Fidelity® funds dedicated to certain programs affiliated with Strategic Advisers.

**Summary Prospectus**

**July 30, 2025**

Before you invest, you may want to review the fund's prospectus, which contains more information about the fund and its risks. You can find the fund's prospectus, reports to shareholders, and other information about the fund (including the fund's SAI) online at fundresearch.fidelity.com/prospectus/sec. You can also get this information at no cost by calling 1-800-FIDELITY or by sending an e-mail request to fidfunddocuments@fidelity.com. The fund's prospectus and SAI dated July 30, 2025 are incorporated herein by reference.

![](img109822_1.jpg)

245 Summer Street, Boston, MA 02210

**Fund Summary**

**Fund:**

**Fidelity® SAI Sustainable U.S. Equity Fund**

**Investment Objective**

Fidelity® SAI Sustainable U.S. Equity Fund seeks long-term growth of capital.

**Fee Table**

The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund.

**Shareholder fees**

---

| | |
|:---|:---|
| **(fees paid directly from your investment)** | **None** |

---

**Annual Operating Expenses**

**(expenses that you pay each year as a % of the value of your investment)**

---

| | |
|:---|:---|
| Management fee  | 0.50%  |
| Distribution and/or Service (12b-1) fees |  |
| Other expenses | 0.06%  |
| **Total annual operating expenses** | 0.56%  |

---

This **example** helps compare the cost of investing in the fund with the cost of investing in other funds.

Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:

---

| | |
|:---|:---|
| 1 year | $57 |
| 3 years | $179 |
| 5 years | $313 |
| 10 years | $701 |

---

**Portfolio Turnover**

The fund pays transaction costs, such as commissions, when it buys and sells securities (or "turns over" its 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 operating expenses or in the example, affect the fund's performance. During the most recent fiscal year, the fund's portfolio turnover rate was 136% of the average value of its portfolio.

**Principal Investment Strategies**

* Normally investing primarily in equity securities.

* Normally investing at least 80% of assets in equity securities of U.S. companies that Fidelity Management & Research Company LLC (FMR) (the Adviser) believes have proven or improving sustainability practices based on an evaluation of such companies' individual environmental, social and governance (ESG) profile.

Equity securities represent an ownership interest, or the right to acquire an ownership interest, in an issuer. Equity securities include common stocks (including depositary receipts evidencing ownership of common stock), preferred stocks and other preferred securities, convertible securities, rights and warrants, and other securities, such as hybrid securities and trust preferred securities, believed to have equity-like characteristics.

The Adviser considers a number of factors to determine whether an issuer is located in or tied economically to a particular country or region including: whether a third-party vendor has assigned a particular country or region classification to the issuer or included the issuer in an index representative of a particular country or region; the issuer's domicile, incorporation, and location of assets; whether the issuer derives at least 50% of its revenues from, or has at least 50% of its assets in, a particular country or region; the source of government guarantees (if any); and the primary trading market or listing exchange. Whether an issuer is located in or tied economically to a particular country can be determined under any of these factors.

Effective December 11, 2025, derivative instruments that provide investment exposure to the investments above or exposure to one or more market risk factors associated with such investments are included in the fund's 80% policy, consistent with the fund's investment policies and limitations with respect to investments in derivatives.

* Using the Adviser's proprietary ESG ratings process to evaluate the current state of an issuer's sustainability practices using a data-driven framework that includes both proprietary and third-party data, and also provide a qualitative forward-looking assessment of an issuer's sustainability outlook provided by the Adviser's fundamental research analysts and ESG team. 

* The Adviser's ESG ratings of issuers are derived from multiple factors, including an issuer's environmental profile, which may include, but is not limited to, carbon and toxic emissions, water management, waste management, vulnerability to the physical impacts of climate change, and research and investment into products, services, and energies that reduce emissions and/or provide opportunities to transition to less carbon-intensive products or operations. An assessment of an issuer's social profile includes, but is not limited to, its approach to diversity and inclusion, human capital management, data privacy, product safety and human rights. With respect to governance, the independence and diversity of an issuer's board, its compensation practices and board oversight of critical ESG issues are considered as part of the assessment. These factors are weighted based on how material the Adviser believes each factor is to an issuer's financial outlook, and not all factors may be applicable to all issuers.

* Investing in issuers that the Adviser believes deliver tangible environmental or social impact through core business operations. An assessment of the impact characteristics of an issuer may involve corporate engagement and an analysis of issuer alignment with the United Nations Sustainable Development Goals using qualitative analysis as well as proprietary or third-party data. For example, issuers that provide access to clean water, education, or clean energy through their core business may be considered to deliver tangible impact. 

* Investing in securities of domestic and foreign issuers.

* In addition to the ESG ratings process, using fundamental analysis of factors such as each issuer's financial condition and industry position, as well as market and economic conditions, to select investments.

* Employing sustainable investing exclusion criteria to avoid investments in issuers that are directly engaged in, and/or derive significant revenue from, certain industries. Please see "Fund Basics - Investment Details - Sustainable Investing Exclusions" for additional information.

**Principal Investment Risks**

* *Stock Market Volatility.*

Stock markets are volatile and can decline significantly in response to adverse issuer, political, regulatory, market, or economic developments. Different parts of the market, including different market sectors, and different types of securities can react differently to these developments.

* *Sustainability Risk.*

Application of Fidelity Management & Research Company LLC's (FMR) (the Adviser) ESG ratings process and/or its sustainable investing exclusion criteria may affect the fund's exposure to certain issuers, sectors, regions, and countries and may affect the fund's performance depending on whether certain investments are in or out of favor. The criteria related to the fund's ESG ratings process and/or adherence to its sustainable investing exclusion criteria may result in the fund forgoing opportunities to buy certain securities when it might otherwise be advantageous to do so, or selling securities for ESG reasons when it might be otherwise disadvantageous for it to do so. As a result, the fund's performance may at times be better or worse than the performance of funds that do not use ESG or sustainability criteria. There are significant differences in interpretations of what it means for an issuer to have positive ESG factors. While the Adviser believes its definitions are reasonable, the portfolio decisions it makes may differ with other investors' or advisers' views. When evaluating an issuer, the Adviser is dependent on information or data obtained through voluntary or third-party reporting that may be incomplete, inaccurate, or unavailable, which could cause the Adviser to incorrectly assess an issuer's business practices.

* *Foreign Exposure.*

Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market, or economic developments and can perform differently from the U.S. market.

* *Issuer-Specific Changes.*

The value of an individual security or particular type of security can be more volatile than, and can perform differently from, the market as a whole.

* *Small- and Mid-Cap Investing.*

The value of securities of small to medium size, less well-known issuers can perform differently from the market as a whole and other types of stocks and can be more volatile than that of larger issuers.

* *Management Risk.*

The Adviser's application of the fund's strategy criteria may not achieve its intended results. The fund could underperform in comparison to other funds with a similar benchmark or similar objectives and investment strategies.

* *High Portfolio Turnover.*

High portfolio turnover (more than 100%) may result in increased transaction costs and potentially higher capital gains or losses. The effects of higher than normal portfolio turnover may adversely affect the fund's performance.

*An investment in the fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency*. *You could lose money by investing in the fund.*

**Performance**

The following information is intended to help you understand the risks of investing in the fund.

The information illustrates the changes in the performance of the fund's shares from year to year and compares the performance of the fund's shares to the performance of a securities market index and an additional index over various periods of time. The additional index has characteristics relevant to the fund's investment strategies. Index descriptions appear in the "Additional Index Information" section of the prospectus. Past performance (before and after taxes) is not an indication of future performance.

Visit www.fidelity.com for more recent performance information.

**Year-by-Year Returns** 

---

| | |
|:---|:---|
| 2023 | 2024 |
| 24.99%<br>| 20.79%<br>|

---

![](img109822_4.jpg)

---

| | | |
|:---|:---|:---|
| *During the periods shown in the chart:* | *Returns* | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*Quarter ended* |
| *Highest Quarter Return* | *12.27%* | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*December 31, 2023* |
| *Lowest Quarter Return* | *-4.81%* | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*September 30, 2023* |
| *Year-to-Date Return* | *4.89%* | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*June 30, 2025* |

---

**Average Annual Returns**

After-tax returns are calculated using the historical highest individual federal marginal income tax rates, but do not reflect the impact of state or local taxes. Actual after-tax returns may differ depending on your individual circumstances. The after-tax returns shown are not relevant if you hold your shares in a retirement account or in another tax-deferred arrangement, such as an employee benefit plan (profit sharing, 401(k), or 403(b) plan). Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of fund shares.

---

| | | |
|:---|:---|:---|
| <br> For the periods ended December 31, 2024 | &nbsp;&nbsp;Past 1<br> year | Life of<br> fund  |
| **Fidelity® SAI Sustainable U.S. Equity Fund** |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;**Return Before Taxes**  | &nbsp;&nbsp;20.79%  | &nbsp;&nbsp;10.94% A |
| &nbsp;&nbsp;&nbsp;&nbsp;**Return After Taxes on Distributions**  | &nbsp;&nbsp;20.32%  | &nbsp;&nbsp;10.68% A |
| &nbsp;&nbsp;&nbsp;&nbsp;**Return After Taxes on Distributions and Sale of Fund Shares** <br>| &nbsp;&nbsp;12.50%  | &nbsp;&nbsp;8.46% A |
| MSCI USA IMI ESG Leaders Index<br> **(reflects no deduction for fees, expenses, or taxes)** | &nbsp;&nbsp; <br> 22.30%  | &nbsp;&nbsp; <br> 12.68%  |
| Russell 3000® Index<br> **(reflects no deduction for fees, expenses, or taxes)** | &nbsp;&nbsp; <br> 23.81%  | &nbsp;&nbsp; <br> 12.33%  |

---

A*From April 14, 2022.*

**Investment Adviser**

FMR (the Adviser) is the fund's manager. Other investment advisers serve as sub-advisers for the fund.

**Portfolio Manager(s)**

Preeti Sayana (Portfolio Manager) has managed the fund since 2025.

**Purchase and Sale of Shares**

**NOT AVAILABLE FOR SALE TO THE GENERAL PUBLIC.**

Shares are offered exclusively to certain clients of the Adviser or its affiliates.

The price to buy one share is its net asset value per share (NAV). Shares will be bought at the NAV next calculated after an order is received in proper form.

The price to sell one share is its NAV. Shares will be sold at the NAV next calculated after an order is received in proper form.

The fund is open for business each day the New York Stock Exchange (NYSE) is open.

There is no purchase minimum for fund shares.

**Tax Information**

Distributions you receive from the fund are subject to federal income tax and generally will be taxed as ordinary income or capital gains, and may also be subject to state or local taxes, unless you are investing through a tax-advantaged retirement account (in which case you may be taxed later, upon withdrawal of your investment from such account).

**Payments to Broker-Dealers and Other Financial Intermediaries**

The fund, the Adviser, Fidelity Distributors Company LLC (FDC), and/or their affiliates may pay intermediaries, which may include banks, broker-dealers, retirement plan sponsors, administrators, or service-providers (who may be affiliated with the Adviser or FDC), for the sale of fund shares and related services. These payments may create a conflict of interest by influencing your intermediary and your investment professional to recommend the fund over another investment. Ask your investment professional or visit your intermediary's web site for more information.

Fidelity Distributors Company LLC (FDC) is a member of the Securities Investor Protection Corporation (SIPC). You may obtain information about SIPC, including the SIPC brochure, by visiting www.sipc.org or calling SIPC at 202-371-8300.

Fidelity, the Fidelity Investments Logo and all other Fidelity trademarks or service marks used herein are trademarks or service marks of FMR LLC. Any third-party marks that are used herein are trademarks or service marks of their respective owners.© 2025 FMR LLC. All rights reserved.

1.9904864.104 EFS-SUM-0725