[Form 4] REPLIGEN CORP Insider Trading Activity

Rhea-AI Filing Summary

Repligen Corp (RGEN) Chief Financial Officer Jason K. Garland reported a non-derivative disposition on 09/25/2025 involving 412 shares of Common Stock sold at a price of $121.68 per share. The filing shows 13,383 shares remained beneficially owned by the reporting person after the transaction. The form identifies the transaction as related to tax withholding: the 412 shares were withheld by the issuer to satisfy the reporting person's tax withholding obligations upon the release of restricted stock units.

Positive

• Compliance action completed: Issuer withheld shares to satisfy tax obligations, consistent with RSU vesting procedures
• Continued ownership: Reporting person retains 13,383 shares after the withholding

Negative

• Reduction in holdings: 412 shares were disposed of (withheld) which decreases beneficial ownership

Insights

Securities Analyst

TL;DR: Insider disposed of a small block of shares via tax withholding, leaving 13,383 shares beneficially owned.

The Form 4 discloses a routine tax-related disposition of 412 shares at $121.68 each, executed on 09/25/2025 and reported by the CFO. This is explicitly described as shares withheld to satisfy tax withholding obligations tied to the release of restricted stock units. The transaction reduces reported beneficial ownership to 13,383 shares. There is no indication in this filing of voluntary open-market selling beyond withholding.

Corporate Governance Expert

TL;DR: Transaction appears to be administrative tax withholding on RSU vesting; not a discretionary trade signal.

The filing's explanation clearly states the disposition represents shares withheld to satisfy tax obligations from RSU release. That characterization typically reflects issuer-side withholding rather than an active sale by the insider. The reporting person remains an officer (CFO) and continues to hold a meaningful residual position of 13,383 shares according to this form.

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

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OMB Number:			3235-0287
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

Garland Jason K

(Last) (First) (Middle)

C/O REPLIGEN CORPORATION

41 SEYON ST., BLDG 1, STE 100

(Street)

WALTHAM MA 02453

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
REPLIGEN CORP [ RGEN ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
09/25/2025

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

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

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

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	09/25/2025		F		412(1)	D	$121.68	13,383	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. 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.

	/s/ Jennifer Carmichael (Attorney in Fact)	09/26/2025
	** 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.
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FAQ

What did the Form 4 filed for RGEN disclose?

The Form 4 reports that CFO Jason K. Garland had 412 shares withheld at a price of $121.68 per share on 09/25/2025, leaving 13,383 shares beneficially owned.

Why were the 412 RGEN shares disposed of according to the filing?

The filing explains the 412 shares were withheld by the issuer to satisfy the reporting person's tax withholding obligations arising from the release of restricted stock units.

Does the Form 4 indicate an open-market sale by the insider for RGEN?

No. The transaction is described as share withholding for tax purposes related to RSU release, not as an open-market voluntary sale.

How many RGEN shares does the reporting person own after the transaction?

The Form 4 shows the reporting person beneficially owned 13,383 shares following the reported transaction.

When was the Form 4 signed and by whom?

The document is signed by Jennifer Carmichael (Attorney in Fact) on 09/26/2025 on behalf of the reporting person.