Stephen J. Denelsky - 17 Mar 2026 Form 4 Insider Report for HARVARD BIOSCIENCE INC (HBIO)

Role: Director
Signature: /s/ Stephen DeNelsky
Issuer symbol: HBIO
Transactions as of: 17 Mar 2026
Net transactions value: $0
Form type: 4
Filing time: 18 Mar 2026, 14:13:07 UTC
Previous filing: 07 Oct 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
DENELSKY STEPHEN J	Director	C/O HARVARD BIOSCIENCE, INC., 84 OCTOBER HILL ROAD, HOLLISTON	/s/ Stephen DeNelsky	18 Mar 2026	0001204320

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	HBIO	Common Stock	Purchase		+10,000	+91%	$4.87^*	21,000	17 Mar 2026	Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Includes (a) 10,000 shares of common stock purchased on March 17, 2026 and (b) 11,000 restricted stock units that fully vest on September 5, 2026.
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 11,000 restricted stock units referenced in Footnote 1(b) were previously reported as covering 110,000 restricted stock units. These numbers have been adjusted to reflect the stock split that occurred on March 13, 2026.