Repligen CEO sells 5,426 shares after option exercise

REPLIGEN CORP (RGEN) reported Form 4 activity by Chief Executive Officer Olivier Loeillot involving an option exercise and share sale.

Rhea-AI Filing Summary

REPLIGEN CORP (RGEN) reported Form 4 activity by Chief Executive Officer Olivier Loeillot involving an option exercise and share sale. On August 20, 2026, he exercised a stock option to acquire 5,426 shares of common stock at an exercise price of $141.79 per share, and on the same date sold 5,426 shares of common stock at $180.00 per share. The option exercise reduced the reported option position by 5,426 shares, leaving 10,852 stock options outstanding after the transaction at the same exercise price and with an expiration date of September 3, 2034. The filing states that these sales were effected pursuant to a Rule 10b5-1 trading plan adopted on August 19, 2025, and that an additional 5,426 shares will vest on each of September 3, 2026 and September 3, 2027.

Insider Trade Summary 10b5-1

Exercise and Sale: 5,426 shares ($207K approx. pre-tax spread)

Exercise and Sale 3 txns

Insider Loeillot Olivier

Role Chief Executive Officer

Sold 5,426 shs ($977K)

Approx. gross sale proceeds $977K

Approx. exercise cost $769K

Approx. pre-tax spread $207K

Type	Security	Shares	Price	Value
Exercise	Stock Option (Right to Buy) F1, F2	5,426	$0.00	$0.00
Exercise	Common Stock F1	5,426	$141.79	$769K
Sale	Common Stock F1	5,426	$180.00	$977K

Holdings After Transaction: Stock Option (Right to Buy) — 10,852 contracts (Direct); Common Stock — 54,246 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. 5,426 shares will vest on each of September 3, 2026, and September 3, 2027.

Key Figures

Options exercised: 5,426 shares Exercise price: $141.79 per share Shares sold: 5,426 shares +5 more

8 metrics

Options exercised 5,426 shares Stock option exercise into common stock on August 20, 2026

Exercise price $141.79 per share Exercise price of stock option exercised on August 20, 2026

Shares sold 5,426 shares Common stock sold on August 20, 2026

Sale price $180.00 per share Price for common stock sales on August 20, 2026

Options remaining after transaction 10,852 shares Stock options to buy common stock remaining after the reported exercise

Option expiration date September 3, 2034 Expiration date of the stock option position after the transaction

Future vesting 5,426 shares on each of September 3, 2026 and September 3, 2027 Scheduled vesting of shares related to the equity award

Rule 10b5-1 plan adoption date August 19, 2025 Date the CEO adopted the trading plan used for these sales

Key Terms

Rule 10b5-1 trading plan, Stock Option (Right to Buy), Exercise or conversion of derivative security

3 terms

Rule 10b5-1 trading plan regulatory

"The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan"

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

"security_title: Stock Option (Right to Buy)"

Exercise or conversion of derivative security financial

"transaction_code_description: Exercise or conversion of derivative security"

FAQ

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

What transactions did RGEN CEO Olivier Loeillot report in this Form 4?

He exercised a stock option for 5,426 shares of Repligen common stock at $141.79 per share and sold 5,426 shares of common stock at $180.00 per share on August 20, 2026, as disclosed in the Form 4.

How many Repligen (RGEN) options does Olivier Loeillot hold after this transaction?

After the reported option exercise, Olivier Loeillot holds 10,852 stock options to buy Repligen common stock, with an exercise price of $141.79 per share and an expiration date of September 3, 2034.

At what prices did the RGEN CEO exercise and sell shares?

He exercised options at an exercise price of $141.79 per share and sold the acquired 5,426 shares of Repligen common stock at a sale price of $180.00 per share on August 20, 2026.

Were the Repligen (RGEN) CEO’s share sales under a Rule 10b5-1 plan?

Yes. The Form 4 states that the sales reported were effected pursuant to a Rule 10b5-1 trading plan adopted by Olivier Loeillot on August 19, 2025.

What future vesting is disclosed for the RGEN CEO’s equity awards?

The filing discloses that 5,426 shares will vest on each of September 3, 2026 and September 3, 2027, providing a schedule for future vesting of equity related to the reported option award.

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

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Accepted by SEC EDGAR 08/21/2026 - 04:06 PM EDT 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)
08/20/2026

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	08/20/2026		M(1)		5,426	A	$141.79	59,672	D
Common Stock	08/20/2026		S(1)		5,426	D	$180	54,246	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)	$141.79	08/20/2026		M(1)			5,426	(2)	09/03/2034	Common Stock	5,426	$0	10,852	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. 5,426 shares will vest on each of September 3, 2026, and September 3, 2027.

Remarks:

	/s/ Jennifer Carmichael (Attorney in Fact)	08/21/2026
	** 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)