Repligen CEO sells 8,404 and 4,542 shares

The chief executive officer's sales were made under a Rule 10b5-1 plan adopted August 19, 2025.

Rhea-AI Filing Summary

REPLIGEN CORP (RGEN) Chief Executive Officer Olivier Loeillot exercised options for 8,404 shares at an exercise price of $154.96 per share and 4,542 shares at $155.38 on September 24, 2026, then sold matching amounts at $190 per share. The sales were made under a Rule 10b5-1 trading plan adopted August 19, 2025.

Insider Trade Summary 10b5-1

Exercise and Sale: 12,946 shares ($452K approx. pre-tax spread)

Exercise and Sale 6 txns

Insider Loeillot Olivier

Role Chief Executive Officer

Sold 12,946 shs ($2.46M)

Approx. gross sale proceeds $2.46M

Approx. exercise cost $2.01M

Approx. pre-tax spread $452K

Type	Security	Shares	Price	Value
Exercise	Stock Option (Right to Buy) F1, F2	8,404	$0.00	$0.00
Exercise	Stock Option (Right to Buy) F1, F3	4,542	$0.00	$0.00
Exercise	Common Stock F1	8,404	$154.96	$1.30M
Sale	Common Stock F1	8,404	$190.00	$1.60M
Exercise	Common Stock F1	4,542	$155.38	$706K
Sale	Common Stock F1	4,542	$190.00	$863K

Holdings After Transaction: Stock Option (Right to Buy) — 21,692 contracts (Direct); Common Stock — 48,369 shares (Direct)

Footnotes (3)

1. F1. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 19, 2025.
2. F2. 4,202 shares will vest on each of October 2, 2026, and October 2, 2027. 4,203 shares will vest on October 2, 2028.
3. F3. 4,542 shares will vest on March 1, 2027, and 4,543 shares will vest on March 1, 2028.

Key Figures

Options exercised: 8,404 shares Exercise price: $154.96 per share Options exercised: 4,542 shares +3 more

6 metrics

Options exercised 8,404 shares September 24, 2026

Exercise price $154.96 per share Options for 8,404 shares exercised September 24, 2026

Options exercised 4,542 shares September 24, 2026

Exercise price $155.38 per share Options for 4,542 shares exercised September 24, 2026

Shares sold 8,404 shares September 24, 2026, at $190 per share

Shares sold 4,542 shares September 24, 2026, at $190 per share

Key Terms

Rule 10b5-1 trading plan, Stock Option (Right to Buy), exercise price, vest

4 terms

Rule 10b5-1 trading plan financial

"pursuant to a Rule 10b5-1 trading plan adopted by the reporting person"

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

Stock Option (Right to Buy) financial

"Stock Option (Right to Buy)"

exercise price financial

"options at an exercise price of $154.96 per share"

The exercise price is the fixed amount at which you can buy or sell an asset, like a stock, when using an options contract. It matters because it helps determine whether exercising the option will be profitable or not, depending on the current market price. Think of it as the set price you agree on today to buy or sell later.

vest financial

"4,202 shares will vest on each of October 2, 2026, and October 2, 2027"

A vest is the process by which an employee earns the right to receive certain benefits or ownership interests, such as stock or retirement funds, over time. It’s similar to earning a reward gradually, ensuring that the benefit becomes fully yours only after a set period or meeting specific conditions. This makes it important for investors because it determines when they can actually claim or use those benefits.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many RGEN shares did the CEO sell, and at what price?

Olivier Loeillot sold 8,404 shares and 4,542 shares of Repligen common stock at $190 per share on September 24, 2026. The sales followed option exercises for matching share amounts, at exercise prices of $154.96 and $155.38 per share, respectively.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

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Available on EDGAR 09/25/2026 - 04:42 PM Accepted by SEC EDGAR 09/25/2026 - 04:09 PM Learn about SEC filing dates

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 MASSACHUSETTS 02453

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/24/2026

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

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

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

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	09/24/2026		M(1)		8,404	A	$154.96	56,773	D
Common Stock	09/24/2026		S(1)		8,404	D	$190	48,369	D
Common Stock	09/24/2026		M(1)		4,542	A	$155.38	52,911	D
Common Stock	09/24/2026		S(1)		4,542	D	$190	48,369	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)	$154.96	09/24/2026		M(1)			8,404	(2)	10/02/2033	Common Stock	8,404	$0	12,607	D
Stock Option (Right to Buy)	$155.38	09/24/2026		M(1)			4,542	(3)	03/01/2035	Common Stock	4,542	$0	9,085	D

Explanation of Responses:

1. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on August 19, 2025.

2. 4,202 shares will vest on each of October 2, 2026, and October 2, 2027. 4,203 shares will vest on October 2, 2028.

3. 4,542 shares will vest on March 1, 2027, and 4,543 shares will vest on March 1, 2028.

Remarks:

	/s/ Jennifer Carmichael (Attorney in Fact)	09/25/2026
	** 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.
* Form 4: SEC 1474 (03-26)