# EDGAR Filing Document

**Accession Number:** 0001562565
**File Stem:** 0001562565-25-000222
**Filing Date:** 2025-12
**Character Count:** 9374
**Document Hash:** 82a7c5c3009216eef4df0726209e4bca
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001562565-25-000222.hdr.sgml**: 20251212

**ACCESSION NUMBER**: 0001562565-25-000222

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20251212

**DATE AS OF CHANGE**: 20251212

**EFFECTIVENESS DATE**: 20251212

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Fidelity Merrimack Street Trust
- **CENTRAL INDEX KEY:** 0001562565

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 0831

**FILING VALUES:**
- **FORM TYPE:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-186372
- **FILM NUMBER:** 251566776

**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 Corporate Bond ETF (Series ID: S000040431)

---

|  |  |  |
|:---|:---|:---|
| Class Name                  | Ticker Symbol | Class ID   |
| Fidelity Corporate Bond ETF | FCOR          | C000125598 |

---

### Fidelity Total Bond ETF (Series ID: S000042567)

---

|  |  |  |
|:---|:---|:---|
| Class Name              | Ticker Symbol | Class ID   |
| Fidelity Total Bond ETF | FBND          | C000131659 |

---

### Fidelity Limited Term Bond ETF (Series ID: S000042569)

---

|  |  |  |
|:---|:---|:---|
| Class Name                     | Ticker Symbol | Class ID   |
| Fidelity Limited Term Bond ETF | FLTB          | C000131661 |

---

### Fidelity Investment Grade Bond ETF (Series ID: S000071131)

---

|  |  |  |
|:---|:---|:---|
| Class Name                         | Ticker Symbol | Class ID   |
| Fidelity Investment Grade Bond ETF | FIGB          | C000225826 |

---

### Fidelity Investment Grade Securitized ETF (Series ID: S000071132)

---

|  |  |  |
|:---|:---|:---|
| Class Name                                | Ticker Symbol | Class ID   |
| Fidelity Investment Grade Securitized ETF | FSEC          | C000225827 |

---

### Fidelity Tactical Bond ETF (Series ID: S000079047)

---

|  |  |  |
|:---|:---|:---|
| Class Name                 | Ticker Symbol | Class ID   |
| Fidelity Tactical Bond ETF | FTBD          | C000239880 |

---

### Fidelity Low Duration Bond ETF (Series ID: S000084018)

---

|  |  |  |
|:---|:---|:---|
| Class Name                     | Ticker Symbol | Class ID   |
| Fidelity Low Duration Bond ETF | FLDB          | C000248144 |

---

## Series and Classes Contracts Data

### Fidelity Corporate Bond ETF (Series ID: S000040431)

| Class ID   | Class Name                  | Ticker Symbol   |
|:---|:---|:---|
| C000125598 | Fidelity Corporate Bond ETF | FCOR            |

### Fidelity Total Bond ETF (Series ID: S000042567)

| Class ID   | Class Name              | Ticker Symbol   |
|:---|:---|:---|
| C000131659 | Fidelity Total Bond ETF | FBND            |

### Fidelity Limited Term Bond ETF (Series ID: S000042569)

| Class ID   | Class Name                     | Ticker Symbol   |
|:---|:---|:---|
| C000131661 | Fidelity Limited Term Bond ETF | FLTB            |

### Fidelity Investment Grade Bond ETF (Series ID: S000071131)

| Class ID   | Class Name                         | Ticker Symbol   |
|:---|:---|:---|
| C000225826 | Fidelity Investment Grade Bond ETF | FIGB            |

### Fidelity Investment Grade Securitized ETF (Series ID: S000071132)

| Class ID   | Class Name                                | Ticker Symbol   |
|:---|:---|:---|
| C000225827 | Fidelity Investment Grade Securitized ETF | FSEC            |

### Fidelity Tactical Bond ETF (Series ID: S000079047)

| Class ID   | Class Name                 | Ticker Symbol   |
|:---|:---|:---|
| C000239880 | Fidelity Tactical Bond ETF | FTBD            |

### Fidelity Low Duration Bond ETF (Series ID: S000084018)

| Class ID   | Class Name                     | Ticker Symbol   |
|:---|:---|:---|
| C000248144 | Fidelity Low Duration Bond ETF | FLDB            |

**Supplement to the Fidelity® Corporate Bond ETF, Fidelity® Investment Grade Bond ETF, Fidelity® Investment Grade Securitized ETF, Fidelity® Limited Term Bond ETF, and Fidelity® Total Bond ETF December 30, 2024 Prospectus**

*Effective on or about March 31, 2026, Julian Potenza will no longer serve as Co-Portfolio Manager of Fidelity® Limited Term Bond ETF.*

*It is expected that Mr. O'Neil will transition off Fidelity® Total Bond ETF effective on or about September 30, 2026. Julian Potenza will become a Co-Portfolio Manager for the fund effective April 1, 2026.* 

Effective April 1, 2026, the following information supplements information for Fidelity® Investment Grade Bond ETF found in the "Fund Summary" section under the "Portfolio Manager(s)" heading.

Julian Potenza (Co-Portfolio Manager) has managed the fund since 2026.

Effective April 1, 2026, the following information supplements information for Fidelity® Total Bond ETF found in the "Fund Summary" section under the "Portfolio Manager(s)" heading.

Julian Potenza (Co-Portfolio Manager) has managed the fund since 2026.

Effective April 1, 2026, the following information supplements the biographical information found in the "Fund Management" section under the "Portfolio Manager(s)" heading.

Julian Potenza is Co-Portfolio Manager of Fidelity® Investment Grade Bond ETF and Fidelity® Total Bond ETF, each of which he has managed since 2026. He also manages other funds. Since joining Fidelity Investments in 2007, Mr. Potenza has worked as a research analyst and portfolio manager.

*Alexandre Karam no longer serves as Co-Portfolio Manager of Fidelity® Limited Term Bond ETF.*

The following information supplements information for Fidelity® Limited Term Bond ETF found in the "Fund Summary" section under the "Portfolio Manager(s)" heading.

Jared Beckerman (Co-Portfolio Manager) has managed the fund since 2025.

The following information supplements the biographical information for Fidelity® Limited Term Bond ETF found in the "Fund Management" section under the "Portfolio Manager(s)" heading.

Jared Beckerman is Co-Portfolio Manager of Fidelity® Limited Term Bond ETF, which he has managed since 2025. He also manages other funds. Since joining Fidelity Investments in 2012, Mr. Beckerman has worked as a research analyst and portfolio manager.

The following information replaces similar information for Fidelity® Total Bond ETF found in the "Fund Summary" section under the "Principal Investment Strategies" heading.

* Allocating assets across investment-grade, high yield, and emerging markets debt securities. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics.

* Investing up to 20% of assets in lower-quality debt securities (those of less than investment-grade quality, also referred to as high yield debt securities or junk bonds).

* Managing the fund to have similar overall interest rate risk to the Bloomberg U.S. Aggregate Bond Index.

The following information replaces similar information for Fidelity® Total Bond ETF found in the "Investment Details" section under the "Principal Investment Strategies" heading.

The Adviser allocates the fund's assets across investment-grade, high yield, and emerging markets debt securities. Emerging markets include countries that have an emerging stock market as defined by MSCI, countries or markets with low- to middle-income economies as classified by the World Bank, and other countries or markets that the Adviser identifies as having similar emerging markets characteristics. Emerging markets tend to have relatively low gross national product per capita compared to the world's major economies and may have the potential for rapid economic growth. The Adviser may invest up to 20% of the fund's assets in lower-quality debt securities.

The Adviser uses the Bloomberg U.S. Aggregate Bond Index as a guide in structuring the fund and selecting its investments. The Adviser manages the fund to have similar overall interest rate risk to the index.

FIXETF-PSTK-1225-111 1.9887760.111 December 12, 2025

**Supplement to the Fidelity® Low Duration Bond ETF December 30, 2024 Prospectus**

*Effective on or about March 31, 2026, Julian Potenza will no longer serve as Co-Portfolio Manager of the fund.*

LOD-PSTK-1225-101 1.9918235.101 December 12, 2025

**Supplement to the Fidelity® Tactical Bond ETF December 30, 2024 Prospectus**

Effective April 1, 2026, the following information supplements information found in the "Fund Summary" section under the "Portfolio Manager(s)" heading.

Julian Potenza (Co-Portfolio Manager) has managed the fund since 2026.

Effective April 1, 2026, the following information supplements the biographical information found in the "Fund Management" section under the "Portfolio Manager(s)" heading.

Julian Potenza is Co-Portfolio Manager of Fidelity® Tactical Bond ETF, which he has managed since 2026. He also manages other funds. Since joining Fidelity Investments in 2007, Mr. Potenza has worked as a research analyst and portfolio manager.

TBE-PSTK-1225-102 1.9910177.102 December 12, 2025