HARVARD BIOSCIENCE (NASDAQ: HBIO) CEO receives 75,000-share stock grant

Rhea-AI Filing Summary

Duke John D reported acquisition or exercise transactions in this Form 4 filing.

HARVARD BIOSCIENCE INC reported that Chief Executive Officer and director John D. Duke received a grant of 75,000 shares of Common Stock on 2026-03-20. The award was reported at a price of $0.0000 per share, indicating a compensation-related grant rather than a market purchase. Following this transaction, his directly owned Common Stock holdings increased to 180,000 shares.

Insights

Equity compensation analyst

CEO receives 75,000-share stock grant, a routine equity compensation event.

The CEO of HARVARD BIOSCIENCE INC, John D. Duke, received a grant of 75,000 shares of Common Stock at a reported price of $0.0000 per share. The filing classifies this as a grant or award acquisition, not an open-market trade.

After the grant, his directly held Common Stock position rose to 180,000 shares, showing that the award meaningfully increases his equity exposure. With no derivative positions listed in this filing, the visible ownership consists of these non-derivative shares only.

This type of stock grant is a standard component of executive compensation and does not, by itself, signal a change in the company’s outlook. It primarily aligns the CEO’s interests with shareholders by increasing his direct share ownership.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Duke John D

Role Chief Executive Officer

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	75,000	$0.00	--

Holdings After Transaction: Common Stock — 180,000 shares (Direct)

Footnotes (1)

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Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Duke John D

(Last) (First) (Middle)

C/O HARVARD BIOSCIENCE, INC.

84 OCTOBER HILL ROAD

(Street)

HOLLISTON MASSACHUSETTS 01746

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
HARVARD BIOSCIENCE INC [ HBIO ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/20/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/20/2026		A		75,000	A	$0	180,000(1)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. See remarks

Remarks:

Includes (a) an award granting 75,000 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) an award of 50,000 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 (d) 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.

	/s/ John D Duke	03/23/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did HBIO report for CEO John D. Duke?

HBIO reported that CEO John D. Duke received a grant of 75,000 shares of Common Stock. The award was recorded at a price of $0.0000 per share and classified as a grant or award acquisition rather than an open-market trade.

How many HBIO shares does the CEO hold after this Form 4 transaction?

After the reported grant, CEO John D. Duke directly holds 180,000 shares of HARVARD BIOSCIENCE INC Common Stock. This total reflects the addition of the 75,000-share award disclosed in the Form 4 insider trading report filed for the transaction.

Was the HBIO CEO’s 75,000-share transaction a market purchase or a grant?

The 75,000-share transaction for HBIO’s CEO was a grant or award acquisition, not a market purchase. It was reported with transaction code “A,” indicating a compensation-related grant at a stated price of $0.0000 per share in the Form 4 filing.

What does transaction code "A" mean in the HBIO Form 4 filing?

Transaction code “A” in the HBIO Form 4 indicates a grant, award, or other acquisition of shares. For CEO John D. Duke, it reflects a 75,000-share Common Stock grant, reported at $0.0000 per share, rather than an open-market buy or sell transaction.

Does the HBIO Form 4 show any derivative securities for the CEO?

The HBIO Form 4 summary shows no derivative transactions or remaining derivative positions for CEO John D. Duke. The reported activity involves only non-derivative Common Stock, consisting of a 75,000-share grant that brings his direct holdings to 180,000 shares.