Repligen CEO sells 4,202 shares at $190 per share

Both reported sales were made under a Rule 10b5-1 trading plan adopted on August 19, 2025.

Rhea-AI Filing Summary

Repligen Corporation’s Chief Executive Officer, Olivier Loeillot, exercised options for 4,202 common shares at $154.96 per share on October 5, 2026. He sold 4,202 shares at $190.00 per share and another 1,333 shares at $178.75 per share; both sales were made under a Rule 10b5-1 trading plan adopted on August 19, 2025. After the exercise, the reported option position was 8,405 options.

Insider Trade Summary 10b5-1

Exercise and sale activity reported; no spread calculated

Exercise and Sale 4 txns

Insider Loeillot Olivier

Role Chief Executive Officer

Sold 5,535 shs ($1.04M)

Approx. gross sale proceeds $1.04M

Approx. exercise cost $651K

Type	Security	Shares	Price	Value
Exercise	Stock Option (Right to Buy) F1, F2	4,202	$0.00	$0.00
Sale	Common Stock F1	1,333	$178.75	$238K
Exercise	Common Stock F1	4,202	$154.96	$651K
Sale	Common Stock F1	4,202	$190.00	$798K

Holdings After Transaction: Stock Option (Right to Buy) — 8,405 contracts (Direct); Common Stock — 45,788 shares (Direct)

Footnotes (2)

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 October 2, 2027. 4,203 shares will vest on October 2, 2028.

Key Figures

Options exercised: 4,202 shares Exercise price: $154.96 per share Shares sold: 4,202 shares +4 more

7 metrics

Options exercised 4,202 shares October 5, 2026

Exercise price $154.96 per share Options exercised on October 5, 2026

Shares sold 4,202 shares October 5, 2026; $190.00 per share

Sale price $190.00 per share Sale on October 5, 2026

Shares sold 1,333 shares October 5, 2026; $178.75 per share

Sale price $178.75 per share Sale on October 5, 2026

Options after exercise 8,405 options Reported after the October 5, 2026 exercise

Key Terms

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

4 terms

Rule 10b5-1 trading plan regulatory

"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)"

vest financial

"4,202 shares will vest on 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.

derivative security financial

"Exercise or conversion of derivative security"

A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.

FAQ

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

How many shares did RGEN CEO Olivier Loeillot sell, and at what prices?

Olivier Loeillot reported sales of 1,333 shares at $178.75 per share and 4,202 shares at $190.00 per share on October 5, 2026. Both sales were made under a Rule 10b5-1 trading plan adopted on August 19, 2025.

How many RGEN options remained after Olivier Loeillot’s exercise?

The reported option position after the exercise was 8,405 options. The footnote states that 4,202 shares will vest on October 2, 2027, and 4,203 shares will vest on October 2, 2028.

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

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Available on EDGAR 10/06/2026 - 04:18 PM Accepted by SEC EDGAR 10/06/2026 - 04:18 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)
10/05/2026

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	10/05/2026		S(1)		1,333	D	$178.75	45,788	D
Common Stock	10/05/2026		M(1)		4,202	A	$154.96	49,990	D
Common Stock	10/05/2026		S(1)		4,202	D	$190	45,788	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	10/05/2026		M(1)			4,202	(2)	10/02/2033	Common Stock	4,202	$0	8,405	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 October 2, 2027. 4,203 shares will vest on October 2, 2028.

Remarks:

	/s/ Jennifer Carmichael (Attorney in Fact)	10/06/2026
	** 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)