# EDGAR Filing Document

**Accession Number:** 0001123494
**File Stem:** 0001171843-26-001839
**Filing Date:** 2026-3
**Character Count:** 21263
**Document Hash:** 58114e56f8decd44067303f08a5856ce
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001171843-26-001839.hdr.sgml**: 20260323

**ACCESSION NUMBER**: 0001171843-26-001839

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13D

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20260323

**DATE AS OF CHANGE**: 20260323

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** HARVARD BIOSCIENCE INC
- **CENTRAL INDEX KEY:** 0001123494
- **STANDARD INDUSTRIAL CLASSIFICATION:** LABORATORY ANALYTICAL INSTRUMENTS [3826]
- **ORGANIZATION NAME:** 08 Industrial Applications and Services
- **EIN:** 043306140
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-60603
- **FILM NUMBER:** 26779937

**BUSINESS ADDRESS:**
- **STREET 1:** 84 OCTOBER HILL RD
- **CITY:** HOLLISTON
- **STATE:** MA
- **ZIP:** 01746
- **BUSINESS PHONE:** 5088938999

**MAIL ADDRESS:**
- **STREET 1:** 84 OCTOBER HILL ROAD
- **CITY:** HOLLISTON
- **STATE:** MA
- **ZIP:** 01746
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Snider William
- **CENTRAL INDEX KEY:** 0001340831

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D

**MAIL ADDRESS:**
- **STREET 1:** 4800 MONTGOMERY LANE
- **STREET 2:** SUITE 230
- **CITY:** BETHESDA
- **STATE:** MD
- **ZIP:** 20814

## Exhibit 99.1

**EXHIBIT 99.1**

#### JOINT FILING AGREEMENT
The undersigned acknowledge and agree that the foregoing statement on Schedule 13D is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on Schedule 13D shall be filed on behalf of each of the undersigned without the necessity of filing additional joint filing statements. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him, her or it contained herein, but shall not be responsible for the completeness and accuracy of the information concerning the other entities or persons, except to the extent that he, she or it knows or has reason to believe that such information is inaccurate.

---

| | | |
|:---|:---|:---|
| Date: March 23, 2026 | BroadOak Income Fund, L.P. | BroadOak Income Fund, L.P. |
|  | By: | /s/ William Snider |
|  | Name: | William Snider |
|  | Title: | Manager |
| Date: March 23, 2026 | BroadOak Fund VI, L.P. | BroadOak Fund VI, L.P. |
|  | By: | /s/ William Snider |
|  | Name: | William Snider |
|  | Title: | Manager |
| Date: March 23, 2026 | BroadOak Capital Partners, LLC | BroadOak Capital Partners, LLC |
|  | By: | /s/ William Snider |
|  | Name: | William Snider |
|  | Title: | Partner |
| Date: March 23, 2026 | William Snider | William Snider |
|  | By: | /s/ William Snider |

---

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**HARVARD BIOSCIENCE INC**

*(Name of Issuer)*

**Common Stock, par value $0.01 per share**

*(Title of Class of Securities)*

**—**

*(CUSIP Number)*

**BroadOak Income Fund, L.P.**<br>c/o William Snider, Partner<br>4800 Montgomery Lane, Suite 230<br>Bethesda MD 20814<br>301-358-2692

*(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)*

**12/17/2025**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BroadOak Income Fund, L.P.** | Name of reporting person<br>**BroadOak Income Fund, L.P.** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**810000.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**810000.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**810000.00** | Aggregate amount beneficially owned by each reporting person<br>**810000.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**15.34%** | Percent of class represented by amount in Row (11)<br>**15.34%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BroadOak Fund VI, L.P.** | Name of reporting person<br>**BroadOak Fund VI, L.P.** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**15000.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**15000.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**15000.00** | Aggregate amount beneficially owned by each reporting person<br>**15000.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**0.33%** | Percent of class represented by amount in Row (11)<br>**0.33%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**BroadOak Capital Partners, LLC** | Name of reporting person<br>**BroadOak Capital Partners, LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**825000.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**825000.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**825000.00** | Aggregate amount beneficially owned by each reporting person<br>**825000.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**15.57%** | Percent of class represented by amount in Row (11)<br>**15.57%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**HC** | Type of Reporting Person (See Instructions)<br>**HC** | |

---

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**William Snider** | Name of reporting person<br>**William Snider** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**X1** | Citizenship or place of organization<br>**X1** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**21000.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**825000.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**21000.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**825000.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**846000.00** | Aggregate amount beneficially owned by each reporting person<br>**846000.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**15.97%** | Percent of class represented by amount in Row (11)<br>**15.97%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

**Comment for Reporting Person:** Note to Rows 7, 9, and 11: Consists of 21,000 shares of Harvard Bioscience, Inc. (the "Issuer") common stock, par value $0.01 per share ("Common Stock") held by William Snider.

Note to Rows 8, 10 and 11: Consists of (i) 60,000 shares of Common Stock issuable upon the exercise of warrants held by BroadOak Income Fund, L.P. ("BroadOak Income Fund"); (ii) 15,000 shares of Common Stock issuable upon the exercise of the warrants held by BroadOak Fund VI, L.P. ("BroadOak Fund VI"); and (iii) 750,000 shares of Common Stock issuable upon the conversion of the convertible loan held by BroadOak Income Fund. BroadOak Capital Partners, LLC ("BroadOak Capital Partners") is the parent of BroadOak Income Fund and BroadOak Fund VI (collectively, the "BroadOak Funds"), and as such may be deemed to share beneficial ownership of the shares of Common Stock underlying the warrants and convertible loan held by the BroadOak Funds. William Snider has sole voting and dispositive power over the shares of common stock underlying the warrants and convertible loan held by the BroadOak Funds, and as such may be deemed to share beneficial ownership of such shares. The number of shares held by the Reporting Persons as disclosed in this filing reflects the 10:1 reverse stock split of the Common Stock effected by the Issuer on March 13, 2026 (the "Stock Split").

Note to Row 13: Based on (i) 4,471,989 shares of Common Stock outstanding as of March 5, 2026, as reported in the Issuer's Form 10-K filed with the U.S. Securities and Exchange Commission (the "SEC") on March 13, 2026, as adjusted to reflect the Stock Split, and (ii) assumes the issuance of shares of Common Stock underlying the warrants and convertible loans held by the BroadOak Funds in the following amounts, as adjusted to reflect the Stock Split: with respect to (A) BroadOak Income Fund, 810,000 shares; (B) BroadOak Fund VI, 15,000 shares; and (C) BroadOak Capital Partners and Mr. Snider, 825,000 shares.

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Common Stock, par value $0.01 per share

**(b) Name of Issuer:**
HARVARD BIOSCIENCE INC

**(c) Address of Issuer's Principal Executive Offices:**
84 October Hill Road, Holliston, MA, 01746

This Schedule 13D (the "Statement") relates to the common stock, par value $0.01 per share (the "Common Stock"), of Harvard Bioscience, Inc., a Delaware corporation (the "Issuer"). The Issuer's principal executive offices are located at 84 October Hill Road, Holliston, Massachusetts 01746.

**Item 4. Purpose of Transaction**

The information contained above in Item 1 and Item 3 of this Schedule 13D is incorporated herein by reference. The Reporting Persons acquired the securities of the Issuer in connection with the Loan Agreement.

Mr. Snider serves a member of the board of directors of the Issuer and, in such capacity, may have influence over the corporate activities of the Issuer, including activities which may relate to items described in subparagraphs (a) through (j) of Item 4 of Schedule 13D. Mr. Snider is a partner of BroadOak Capital Partners and manager of BroadOak Income Fund and BroadOak Fund VI. Subject to the Issuer's Insider Trading Policy and other applicable policies, Mr. Snider may from time to time buy or sell securities of the Issuer as appropriate for his personal circumstances, and may receive compensation from the Issuer, in the form of cash, equity or otherwise, in connection with his service as a director of the Issuer.

Except as described in this Schedule 13D, the Reporting Persons do not have any present plans or proposals that relate to or would result in any of the actions described in subparagraphs (a) through (j) of Item 4 of Schedule 13D, although, subject to the agreements described herein, the Reporting Persons, at any time and from time to time, may review, reconsider and change their position and/or change their purpose and/or develop such plans and may seek to influence management of the Issuer or the board of directors of the Issuer with respect to the business and affairs of the Issuer and may from time to time consider pursuing or proposing such matters with advisors, the Issuer or other persons. The Reporting Persons may in the future take such actions with respect to the Loan Agreement, financings or refinancings of the Issuer, and their investment in the Issuer as they deem appropriate including, without limitation, engaging in communications with management and the board of directors of the Issuer, engaging in discussions with stockholders of the Issuer or other third parties about the Issuer, the Loan Agreement and the Reporting Persons' investment, including potential business combinations or dispositions involving the Issuer or certain of its businesses, making recommendations or proposals to the Issuer concerning changes to the capitalization, ownership structure, board structure (including board composition), potential business combinations or dispositions involving the Issuer or certain of its businesses, or changing their intention with respect to any and all matters referred to in Items 3 and 4.

**Item 5. Interest in Securities of the Issuer**

**(a)**
Number of shares of Common Stock beneficially owned: (i) BroadOak Income Fund, L.P., 810,000 shares; (ii) BroadOak Fund VI, L.P., 15,000 shares; (iii) BroadOak Capital Partners, LLC, 825,000 shares; and (iv) William Snider, 846,000 shares.

Percent of class: (i) BroadOak Income Fund, L.P., 15.34%; (ii) BroadOak Fund VI, L.P., 0.33%; (iii) BroadOak Capital Partners, LLC, 15.57%; and (iv) William Snider, 15.97%.

The percentage ownership was calculated based on (i) 4,471,989 shares of Common Stock outstanding as of March 5, 2026, as reported in the Issuer's Form 10-K filed with the U.S. Securities and Exchange Commission (the "SEC") on March 13, 2026, as adjusted to reflect the Stock Split, and (ii) assumes the issuance of shares of Common Stock underlying the warrants and convertible loans held by the BroadOak Funds in the following amounts, as adjusted to reflect the Stock Split: with respect to (A) BroadOak Income Fund, 810,000 shares; (B) BroadOak Fund VI, 15,000 shares; and (C) BroadOak Capital Partners and Mr. Snider, 825,000 shares.

**(b)**
Number of shares as to which such person has sole power to vote or to direct the vote: (i) BroadOak Income Fund, L.P., 0 shares; (ii) BroadOak Fund VI, L.P., 0 shares; (iii) BroadOak Capital Partners, LLC, 0 shares; and (iv) William Snider, 21,000 shares.

Number of shares as to which such person has shared power to vote or to direct the vote: (i) BroadOak Income Fund, L.P., 810,000 shares; (ii) BroadOak Fund VI, L.P., 15,000 shares; (iii) BroadOak Capital Partners, LLC, 825,000 shares; and (iv) William Snider, 825,000 shares.

Number of shares as to which such person has sole power to dispose or to direct the disposition of: (i) BroadOak Income Fund, L.P., 0 shares; (ii) BroadOak Fund VI, L.P., 0 shares; (iii) BroadOak Capital Partners, LLC, 0 shares; and (iv) William Snider, 21,000 shares.

Number of shares as to which such person has shared power to dispose or to direct the disposition of: (i) BroadOak Income Fund, L.P., 810,000 shares; (ii) BroadOak Fund VI, L.P., 15,000 shares; (iii) BroadOak Capital Partners, LLC, 825,000 shares; and (iv) William Snider, 825,000 shares.

**(c)**
Except as reported in this Schedule 13D, none of the Reporting Persons has effected any transactions in the Common Stock during the past sixty (60) days.

Mr. Snider has purchased an aggregate of 21,000 shares of Common Stock in open market transactions with personal funds. On March 16, 2026, Mr. Snider purchased 15,525 shares at a weighted average price of $4.99. (The shares were purchased in multiple transactions at prices ranging from $4.85 to $5.00). On March 17, 2026, Mr. Snider purchased 8,475 shares at a weighted average price of $4.85. (The shares were purchased in multiple transactions at prices ranging from $4.80 to $4.95). Mr. Snider undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, specific trade amounts and pricing at which the respective transactions were effected.

**Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.**

The information contained above in Item 3 of this Schedule 13D is incorporated herein by reference.

Mr. Snider will be entitled to receive compensation as a director of the Issuer. In such capacity, he may also be granted equity awards with respect to the Common Stock from time to time.

Except as disclosed in this Schedule 13D, there are no contracts, arrangements, understandings or relationships (legal or otherwise) between the Reporting Persons with respect to the securities of the Issuer.

### SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** BroadOak Income Fund, L.P.

**Signature:** /s/ William Snider

**Name/Title:** William Snider, Manager

**Date:** 03/23/2026

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** BroadOak Fund VI, L.P.

**Signature:** /s/ William Snider

**Name/Title:** William Snider, Manager

**Date:** 03/23/2026

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** BroadOak Capital Partners, LLC

**Signature:** /s/ William Snider

**Name/Title:** William Snider, Partner

**Date:** 03/23/2026

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** William Snider

**Signature:** /s/ William Snider

**Name/Title:** William Snider

**Date:** 03/23/2026