James Bylund - 27 Feb 2026 Form 4 Insider Report for REPLIGEN CORP (RGEN)

Role: Chief Operating Officer
Signature: /s/ Jennifer Carmichael (Attorney in Fact)
Issuer symbol: RGEN
Transactions as of: 27 Feb 2026
Net transactions value: -$494,315
Form type: 4
Filing time: 03 Mar 2026, 14:02:34 UTC
Previous filing: 19 Nov 2025
Next filing: 05 Mar 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Bylund James	Chief Operating Officer	C/O REPLIGEN CORPORATION, 41 SEYON ST., BLDG 1, STE 100, WALTHAM	/s/ Jennifer Carmichael (Attorney in Fact)	03 Mar 2026	0001849642

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	RGEN	Common Stock	Tax liability	$190,263	-1,478	-6.9%	$128.73	20,042	27 Feb 2026	Direct	F1
transaction	RGEN	Common Stock	Tax liability	$304,052	-2,433	-12%	$124.97	17,609	02 Mar 2026	Direct	F1

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

Explanation of Responses:

Id	Content
F1	Represents the number of shares withheld by the Issuer to satisfy tax withholding obligations of the reporting person that arose upon the release of restricted stock units.