Repligen Form 4: Anthony Hunt option exercise and multiple sales disclosed

Rhea-AI Filing Summary

Repligen Corp (RGEN) director Anthony Hunt exercised options and sold shares on 09/10/2025 under a documented plan. Mr. Hunt exercised a stock option to acquire 20,000 shares at an exercise price of $33.87, resulting in 20,000 newly acquired shares recorded in Table II. On the same date he sold multiple blocks of common stock under a 10(b)5-1 trading plan, with weighted-average sale prices reported at $116.34, $118.32, $119.64, $120.19, $121.42 and $122.23 for different tranches. After these transactions his direct beneficial ownership of common stock is reported as 100,743 shares and he beneficially owns 182,344 shares underlying options.

Insights

Financial Analyst

TL;DR: Director exercised low-strike options and executed sizable sales, leaving meaningful vested option exposure.

The filing shows an option exercise at a $33.87 strike for 20,000 shares paired with substantial open-market dispositions executed under a 10(b)5-1 plan at prices between ~$116 and ~$122. The exercise converted low-cost option economics into shares, while the sales monetized a portion of equity at multi-year high price bands. Post-transaction direct common shares are reported at 100,743 while option-based beneficial ownership totals 182,344 shares, with remaining vesting schedules disclosed.

Corporate Governance Expert

TL;DR: Transactions appear compliant and documented; sales were conducted under a pre-established 10(b)5-1 plan.

The Form 4 discloses use of a 10(b)5-1 trading plan adopted December 9, 2024, for the reported sales and includes weighted-average prices and a commitment to provide detailed per-tranche pricing on request. The signature by an attorney-in-fact indicates the filing was executed via authorized representative. Vesting schedules for remaining option shares are explicitly stated, supporting transparency about future potential dilution or insider holdings.

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^*

Hunt Anthony

(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)
09/10/2025

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	09/10/2025		M		20,000	A	$33.87	129,854	D
Common Stock	09/10/2025		S(1)		96	D	$116.34	129,758	D
Common Stock	09/10/2025		S(1)		1,108	D	$118.32(2)	128,650	D
Common Stock	09/10/2025		S(1)		3,262	D	$119.64(3)	125,388	D
Common Stock	09/10/2025		S(1)		14,882	D	$120.19(4)	110,506	D
Common Stock	09/10/2025		S(1)		7,584	D	$121.42(5)	102,922	D
Common Stock	09/10/2025		S(1)		2,179	D	$122.23(6)	100,743	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
Stock Option (Right to Buy)	$33.87	09/10/2025		M			20,000	(7)	03/01/2028	Common Stock	20,000	$0.00	182,344	D

Explanation of Responses:

1. Sale of common stock was effected pursuant to a 10(b)5-1 trading plan adopted on December 9, 2024.

2. $118.32 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $117.80 to $118.76, 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 sold at each separate price within the range.

3. $119.64 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $118.83 to $119.83, 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 sold at each separate price within the range.

4. $120.19 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $119.85 to $120.80, 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 sold at each separate price within the range.

5. $121.42 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $120.86 to $121.86, 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 sold at each separate price within the range.

6. $122.23 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $121.92 to $122.61, 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 sold at each separate price within the range.

7. 207,344 of the shares underlying this option have vested. The remaining shares vest as follows: 28,777 shares on March 1, 2026, and 28,778 shares on March 1, 2027.

	/s/ Jennifer Carmichael (Attorney in Fact)	09/11/2025
	** 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 director Anthony Hunt do on 09/10/2025 (RGEN)?

He exercised a stock option for 20,000 shares at a $33.87 strike and sold multiple blocks of common stock under a 10(b)5-1 plan at weighted-average prices between $116.34 and $122.23.

How many shares does Anthony Hunt beneficially own after the transactions?

The filing reports 100,743 shares of common stock beneficially owned directly and 182,344 shares underlying options after the reported transactions.

Were the sales part of a trading plan?

Yes. The sales were effected pursuant to a 10(b)5-1 trading plan adopted on December 9, 2024, as disclosed in the Form 4 explanations.

What is the exercise/vesting status of the option shares?

The filing states 207,344 underlying option shares have vested; remaining option shares vest 28,777 on March 1, 2026 and 28,778 on March 1, 2027.

Who signed the Form 4 filing for Anthony Hunt?

The Form 4 is signed by Jennifer Carmichael on behalf of the reporting person, dated 09/11/2025.