Repligen (RGEN) director trust buys 1,800 shares at $112.128

Rhea-AI Filing Summary

Repligen Corp director Martin D. Madaus, through the Martin D. Madaus 2011 Revocable Trust, bought 1,800 shares of Repligen common stock in an open-market purchase. The weighted average price was $112.128 per share, with trades ranging from $111.72 to $112.35. Following these transactions, Madaus directly holds 5,586 shares, the revocable trust holds 1,800 shares, and a spouse trust holds 11 shares.

Insider Trade Summary

Net Buyer: 1,800 shares ($201,830)

Net Buy 3 txns

Insider Madaus Martin D

Role Director

Bought 1,800 shs ($202K)

Type	Security	Shares	Price	Value
Purchase	Common Stock	1,800	$112.128	$202K
holding	Common Stock	--	--	--
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 1,800 shares (Indirect, By Martin D. Madaus 2011 Revocable Trust); Common Stock — 5,586 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^*

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 did Repligen (RGEN) director Martin D. Madaus report in this Form 4?

Martin D. Madaus reported that his 2011 Revocable Trust bought 1,800 Repligen common shares in an open-market transaction. The filing also updates his direct holdings to 5,586 shares and notes 11 additional shares held indirectly through a spouse trust.

How many Repligen (RGEN) shares did the Madaus 2011 Revocable Trust purchase?

The Martin D. Madaus 2011 Revocable Trust purchased 1,800 shares of Repligen common stock. These were acquired in an open-market transaction and represent indirect ownership associated with Madaus, separate from his directly held shares and those held in a spouse trust.

At what price were the Repligen (RGEN) shares bought in this insider transaction?

The 1,800 Repligen shares were bought at a weighted average price of $112.128 per share. According to the filing, individual trades occurred at prices ranging from $111.72 to $112.35, inclusive, across multiple transactions on the reported date.

What are Martin D. Madaus’s total reported Repligen (RGEN) share holdings after this transaction?

After the reported transactions, Madaus directly holds 5,586 Repligen shares. Indirectly, 1,800 shares are held through the Martin D. Madaus 2011 Revocable Trust and 11 additional shares are held through a spouse trust, as disclosed in the Form 4.

Was this Repligen (RGEN) Form 4 transaction a purchase or sale?

The Form 4 reports a purchase. The Martin D. Madaus 2011 Revocable Trust conducted an open-market buy of 1,800 Repligen common shares, classified under transaction code “P,” which indicates a purchase in an open market or private transaction.

How is the Repligen (RGEN) insider ownership structured for Martin D. Madaus?

Madaus’s Repligen ownership includes 5,586 shares held directly in his name. Indirectly, 1,800 shares are held by the Martin D. Madaus 2011 Revocable Trust and 11 shares are held by a spouse trust, reflecting different ownership capacities in the filing.