# EDGAR Filing Document

**Accession Number:** 0000917286
**File Stem:** 0000917286-25-000092
**Filing Date:** 2025-6
**Character Count:** 12107
**Document Hash:** df5609a17b0dd51584675608ff180505
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000917286-25-000092.hdr.sgml**: 20250627

**ACCESSION NUMBER**: 0000917286-25-000092

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20250627

**DATE AS OF CHANGE**: 20250627

**EFFECTIVENESS DATE**: 20250627

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** FIDELITY HEREFORD STREET TRUST
- **CENTRAL INDEX KEY:** 0000917286

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

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-52577
- **FILM NUMBER:** 251083547

**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

## Series and Classes Contracts Data

### Fidelity Flex Government Money Market Fund (Series ID: S000056367)

| Class ID   | Class Name                                 | Ticker Symbol   |
|:---|:---|:---|
| C000177594 | Fidelity Flex Government Money Market Fund | FLGXX           |

Fidelity Flex® Funds

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

**Fidelity Flex® Government Money Market Fund**/FLGXX

**Summary Prospectus**

**June 28, 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 1-800-835-5095 or by sending an e-mail request to fidfunddocuments@fidelity.com. The fund's prospectus and SAI dated June 28, 2025 are incorporated herein by reference.

![](img109334_1.jpg)

245 Summer Street, Boston, MA 02210

**Fund Summary**

**Fund:**

**Fidelity Flex® Government Money Market Fund**

**Investment Objective**

Fidelity Flex® Government Money Market Fund seeks as high a level of current income as is consistent with preservation of capital and liquidity.

**Fee Table**

The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. **You may pay other fees, such as brokerage commissions, which are not reflected in the tables and examples below.**

**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  | 0.00%  |
| Distribution and/or Service (12b-1) fees |  |
| Other expenses | 0.00%  |
| **Total annual operating expenses** | 0.00% A |

---

AThe fund is available only to certain fee-based accounts and advisory programs offered by Fidelity. Advisory account clients, retirement plans, plan sponsors and/or plan participants typically pay an advisory fee that generally covers investment advisory and administrative services.

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. This example does not include any fees paid at the fee-based account or plan level. 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 | $0 |
| 3 years | $0 |
| 5 years | $0 |
| 10 years | $0 |

---

**Principal Investment Strategies**

* Normally investing at least 99.5% of total assets in cash, U.S. Government securities and/or repurchase agreements that are collateralized fully (i.e., collateralized by cash or government securities).

* Investing in U.S. Government securities issued by entities that are chartered or sponsored by Congress but whose securities are neither issued nor guaranteed by the U.S. Treasury.

* Investing in compliance with industry-standard regulatory requirements for money market funds for the quality, maturity, liquidity, and diversification of investments.

* In addition, the fund normally invests at least 80% of its assets in U.S. Government securities and repurchase agreements for those securities.

U.S. Government securities are high-quality securities issued or guaranteed by the U.S. Treasury or by an agency or instrumentality of the U.S. Government. U.S. Government securities may be backed by the full faith and credit of the U.S. Treasury, the right to borrow from the U.S. Treasury, or the agency or instrumentality issuing or guaranteeing the security. Certain issuers of U.S. Government securities, including Fannie Mae, Freddie Mac, and the Federal Home Loan Banks, are sponsored or chartered by Congress but their securities are neither issued nor guaranteed by the U.S. Treasury. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security.

A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. A repurchase agreement entered into by the fund may be collateralized by U.S. Government securities or cash.

**Principal Investment Risks**

* *Interest Rate Changes.*

Interest rate increases can cause the price of a money market security to decrease.

* *Income Risk.*

A low or negative interest rate environment can adversely affect the fund's yield.

* *Issuer-Specific Changes.*

A decline in the credit quality of an issuer or a provider of credit support (such as guarantees) or a maturity-shortening structure (such as demand and put features) for a security can cause the price of a money market security to decrease.

*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 not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency*. *Fidelity Investments and its affiliates, 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.*

*The fund will not impose a fee upon the sale of your shares.*

**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. Past performance is not an indication of future performance.

The performance shown does not reflect the impact of any fees paid at the fee-based account or plan level.

Visit www.401k.com and log in or www.fidelity.com for more recent performance information.

**Year-by-Year Returns** 

---

| | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|
| 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 |
| 1.91%<br>| 2.27%<br>| 0.49%<br>| 0.07%<br>| 1.67%<br>| 5.22%<br>| 5.37%<br>|

---

![](img109334_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* | *1.37%* | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*December 31, 2023* |
| *Lowest Quarter Return* | *0.01%* | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*June 30, 2021* |
| *Year-to-Date Return* | *1.09%* | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;*March 31, 2025* |

---

**Average Annual Returns**

---

| | | | |
|:---|:---|:---|:---|
| <br> For the periods ended December 31, 2024 | &nbsp;&nbsp;Past 1<br> year  | &nbsp;&nbsp;Past 5<br> years  | &nbsp;&nbsp;Life of<br>fund  |
| **Fidelity Flex® Government Money Market Fund** | &nbsp;&nbsp;5.37% | &nbsp;&nbsp;2.54% | &nbsp;&nbsp;2.26%A |

---

A*From March 8, 2017.*

**Investment Adviser**

Fidelity Management & Research Company LLC (FMR) (the Adviser) is the fund's manager. Other investment advisers serve as sub-advisers for the fund.

**Purchase and Sale of Shares**

Shares are available only to certain fee-based accounts and advisory programs offered by Fidelity. Shares also may be available to certain broker-dealers that have entered into arrangements with Fidelity.

You may buy or sell shares in various ways:

**Internet**

---

| | |
|:---|:---|
| **<u>Plan Accounts:</u>** | **<u>All Other Accounts:</u>** |
| **www.401k.com** | **www.fidelity.com** |

---

**Phone**

**<u>Plan Accounts:</u>**

**For Individual Accounts (investing through a retirement plan sponsor or other institution), refer to your plan materials or contact that institution directly.**

**For Retirement Plan Level Accounts:**

**Corporate Clients 1-800-962-1375**

**"Not for Profit" Clients 1-800-343-0860**

**<u>All Other Accounts:</u>**

**1-800-544-3455**

**Mail (Plan Accounts Only)**

---

| | |
|:---|:---|
| **Redemptions:**<br> **Fidelity Investments**<br> **P.O. Box 770001**<br> **Cincinnati, OH 45277-0035** | ***Overnight Express:***<br> **Fidelity Investments**<br> **100 Crosby Parkway**<br> **Covington, KY 41015** |

---

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.

Even if the NYSE is closed, the fund will be open for business on those days on which the Federal Reserve Bank of New York (New York Fed) is open, the primary trading markets for the fund's portfolio instruments are open, and the fund's management believes there is an adequate market to meet purchase and redemption requests.

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 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. Currently, the Board of Trustees of the fund has not authorized such payments for shares of the fund. 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.

1.9880808.110 ZGY-SUM-0625