Repligen CEO and director reports 7,041-share stock sale at $170

Rhea-AI Filing Summary

Repligen Corporation (RGEN) reported an insider stock sale by its Chief Executive Officer, who is also a director. On 11/25/2025, the executive sold 7,041 shares of common stock at a price of $170 per share, as shown in a Form 4 filing. After this transaction, the executive directly held 35,898 shares of Repligen common stock.

The sale was carried out under a pre-arranged Rule 10b5-1 trading plan that was adopted on December 12, 2024, which is designed to allow insiders to sell shares according to a set schedule.

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).

X

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^*

Loeillot Olivier

(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
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
11/25/2025

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	11/25/2025		S		7,041	D	$170(1)	35,898	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. Sale of common stock was effected pursuant to a 10(b)5-1 trading plan adopted on December 12, 2024.

	/s/ Jennifer Carmichael (Attorney in Fact)	11/26/2025
	** 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 insider transaction did Repligen (RGEN) report in this Form 4?

The filing shows that Repligen's Chief Executive Officer and director sold 7,041 shares of common stock on 11/25/2025 at a price of $170 per share.

How many Repligen (RGEN) shares does the reporting person hold after the sale?

Following the reported transaction, the executive beneficially owned 35,898 shares of Repligen common stock in direct ownership.

Was the Repligen (RGEN) CEO's stock sale under a Rule 10b5-1 plan?

Yes. The filing states that the sale was effected pursuant to a Rule 10b5-1 trading plan adopted on December 12, 2024.

What role does the reporting person hold at Repligen (RGEN)?

The reporting person is identified as both a Director and an Officer, serving as Chief Executive Officer of Repligen Corporation.

What type of securities were involved in the Repligen (RGEN) Form 4 transaction?

The transaction involved Repligen Corporation common stock reported in Table I as a sale of non-derivative securities.

Were any derivative securities reported in this Repligen (RGEN) Form 4?

The filing includes a standard Table II layout for derivative securities, but the provided excerpt does not show any specific derivative transactions filled in.