HARVARD BIOSCIENCE INC — Director's Dealing 2026

Mar 17, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: HARVARD BIOSCIENCE INC (HBIO)
CIK: 0001123494
Period of Report: 2026-03-16

Reporting Person: Duke John D (Director, Chief Executive Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2026-03-16	Common Stock	P	5000	$5.01	Acquired	105000	Direct

Footnotes

F1: Includes (a) 5,000 shares of common stock purchased on March 16, 2026, (b) an award of 50,000 restricted stock units (RSUs) that will vest in three equal installments on August 8, 2026, 2027 and 2028, subject to the terms set forth in an award agreement between the Issuer and the Reporting Person and (c) an award of 50,000 RSUs with performance based vesting conditions. These RSUs will vest upon the achievement of a relative total shareholder return of the Issuer's common stock during the period from August 8, 2025 to the earlier of (i) July 30, 2028, and (ii) the date of a change of control, measured relative to the Russell2000 index, subject to the terms set forth in an award agreement between the Issuer and the Reporting Person. The target number of these RSUs that may be earned is reported above; the maximum amount is 150% of the number reported.

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 50,000 restricted stock units referenced in Footnote 1(b) were previously reported as covering 500,000 restricted stock units and the 50,000 restricted stock units referenced in Footnote 1(c) were previously reported as covering 500,000 restricted stock units. These numbers have been adjusted to reflect the stock split that occurred on March 13, 2026.