# EDGAR Filing Document

**Accession Number:** 0000917286
**File Stem:** 0000917286-25-000138
**Filing Date:** 2025-10
**Character Count:** 2190
**Document Hash:** 5ebc098c54ff74486695854a07df4577
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000917286-25-000138.hdr.sgml**: 20251001

**ACCESSION NUMBER**: 0000917286-25-000138

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20251001

**DATE AS OF CHANGE**: 20251001

**EFFECTIVENESS DATE**: 20251001

**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:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-52577
- **FILM NUMBER:** 251362749

**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 Series Treasury Bill Index Fund (Series ID: S000062807)

---

|  |  |  |
|:---|:---|:---|
| Class Name                               | Ticker Symbol | Class ID   |
| Fidelity Series Treasury Bill Index Fund | FHQFX         | C000203454 |

---

## Series and Classes Contracts Data

### Fidelity Series Treasury Bill Index Fund (Series ID: S000062807)

| Class ID   | Class Name                               | Ticker Symbol   |
|:---|:---|:---|
| C000203454 | Fidelity Series Treasury Bill Index Fund | FHQFX           |

**Supplement to the Fidelity® Series Treasury Bill Index Fund June 28, 2025 Prospectus**

The following information supplements information found in the "Fund Summary" section under the "Portfolio Manager(s)" heading.

Van Eswara (Co-Portfolio Manager) has managed the fund since 2025.

The following information supplements the biographical information found in the "Fund Management" section under the "Portfolio Manager(s)" heading.

Van Eswara is Co-Portfolio Manager of Fidelity® Series Treasury Bill Index Fund, which he has managed since 2025. He also manages other funds. Since joining Fidelity Investments in 2003, Mr. Eswara has worked as a trader and portfolio manager.

XSB-PSTK-1025-103 1.9900311.103 October 1, 2025