Frost Mark T. - 20 Mar 2026 Form 4 Insider Report for HARVARD BIOSCIENCE INC (HBIO)

Reporting relationship: Chief Financial Officer
Issuer ticker: HBIO
Reported as of: 20 Mar 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 01 Apr 2026, 09:57:46 UTC
Prior SEC filing: 01 Apr 2026
Source filing: View source filing
Reporting owner signature: /s/ Mark Frost

Key filing fact

Frost Mark T. filed Form 4 for HARVARD BIOSCIENCE INC (HBIO) on 01 Apr 2026.

Key facts

This page summarizes Frost Mark T.'s Form 4 filing for HARVARD BIOSCIENCE INC (HBIO).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 01 Apr 2026, 09:57.

Change

Previous filing in this sequence was filed on 01 Apr 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001310262 Primary reporting owner

Frost Mark T

Relationship: Chief Financial Officer
Address: C/O HARVARD BIOSCIENCE, INC., 84 OCTOBER HILL ROAD, HOLLISTON
Signature: /s/ Mark Frost
Signature date: 01 Apr 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

HBIO transaction

Common Stock

Award

Transaction value
Shares: +30,000
Change %: +171%
Price: $0.000000^*
Shares after: 47,500
Date: 20 Mar 2026
Ownership: Direct
Footnotes: F1, F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

Includes (a) an award granting 30,000 restricted stock units (RSUs) that will vest in three equal installments on March 20, 2027, 2028, and 2029, subject to the terms set forth in an award agreement between the Issuer and the Reporting Person, (b) 5,000 shares of common stock purchased on March 16, 2026, (c) 10,000 RSUs that will vest on May 12, 2026, and (d) 2,500 shares of common stock beneficially owned by the Reporting Person.

Footnote F2

On March 13, 2026, the common stock of Harvard Bioscience, Inc. underwent a reverse stock split in a ratio of 10-for-1. The 10,000 RSUs referenced in Footnote 1(c) were previously reported as covering 100,000 RSUs and the 2,500 shares of common stock referenced in Footnote 1(d) were previously reported as covering 25,000 shares of common stock. These numbers have been adjusted to reflect the stock split that occurred on March 13, 2026.