[Form 4] Repligen Corp Insider Trading Activity

Rhea-AI Filing Summary

Martin D. Madaus, a director of Repligen Corporation (RGEN), reported an insider purchase of 1,800 shares of common stock on 08/08/2025 at a weighted-average price of $112.128 per share. The filing shows those 1,800 shares are beneficially owned and held indirectly through the Martin D. Madaus 2011 Revocable Trust. The Form 4 also lists a disposition of 5,586 shares and indicates 11 shares held indirectly in a spouse trust. The report identifies the filer as a director and provides the weighted-average purchase price and the trustee holdings without additional context on total holdings or prior positions.

Insights

Financial Analyst

TL;DR: Director purchase of 1,800 shares at $112.128 disclosed; transaction is routine disclosure lacking context to assess materiality.

The Form 4 documents a purchase of 1,800 Repligen shares at a weighted-average price of $112.128, producing 1,800 shares beneficially owned via a revocable trust. The filing also records a disposition of 5,586 shares and 11 shares tied to a spouse trust. Without information on the reporter's total pre- and post-transaction holdings or the company's outstanding shares, the market impact or materiality cannot be determined from this disclosure alone.

Corporate Governance Expert

TL;DR: Form 4 shows compliance with Section 16 reporting: director transactions and indirect trust holdings are disclosed.

The document reflects standard Section 16 reporting by a director and notes indirect ownership via the Martin D. Madaus 2011 Revocable Trust and a spouse trust. The report includes a weighted-average purchase price and an explicit note explaining the price range. The involvement of an attorney-in-fact as signer is noted. The filing is informative for ownership structure but lacks broader ownership context required to judge governance implications.

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
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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).

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^*

Madaus Martin D

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
08/08/2025

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	08/08/2025		P		1,800	A	$112.128(1)	1,800	I	By Martin D. Madaus 2011 Revocable Trust
Common Stock								5,586	D
Common Stock								11	I	Spouse Trust

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. The price reported is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $111.72 to $112.35, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range.

	/s/ Marc Baumgartner (Attorney in Fact)	08/12/2025
	** 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.
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.

FAQ

What transaction did Martin D. Madaus report on the Form 4 for RGEN?

He reported a purchase of 1,800 shares of Repligen common stock on 08/08/2025 at a weighted-average price of $112.128 per share.

How many shares does the filing show as beneficially owned after the reported purchase?

The filing shows 1,800 shares beneficially owned following the reported purchase, held indirectly through the Martin D. Madaus 2011 Revocable Trust.

Does the Form 4 report any dispositions or other holdings?

Yes. The form lists a disposition of 5,586 shares and indicates 11 shares held indirectly in a spouse trust; no dates or prices for those entries are provided in the text.

What is the reporting person's relationship to Repligen?

The reporting person, Martin D. Madaus, is identified as a Director of Repligen Corporation.

Were any derivative securities reported in this filing?

No. Table II for derivative securities contains no reported transactions or holdings in the provided content.

Who signed the Form 4 on behalf of the reporting person?

The form is signed by Marc Baumgartner (Attorney in Fact) as indicated in the filing.