Olivier Loeillot - 24 Sep 2026 Form 4 Insider Report for REPLIGEN CORP (RGEN)

Reporting relationship: Chief Executive Officer, Director
Issuer ticker: RGEN
Reported as of: 24 Sep 2026
Net transaction value: -$2,459,740
SEC form: 4
Accepted by SEC: 25 Sep 2026, 16:09:43 UTC
Prior SEC filing: 22 Sep 2026
Source filing: View source filing
Reporting owner signature: /s/ Jennifer Carmichael (Attorney in Fact)

Key filing fact

Olivier Loeillot filed Form 4 for REPLIGEN CORP (RGEN) on 25 Sep 2026.

Key facts

This page summarizes Olivier Loeillot's Form 4 filing for REPLIGEN CORP (RGEN).
6 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 25 Sep 2026, 16:09.

Change

Previous filing in this sequence was filed on 22 Sep 2026.
Current net transaction value: -$2,459,740.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001995525 Primary reporting owner

Loeillot Olivier

Relationship: Chief Executive Officer, Director
Address: C/O REPLIGEN CORPORATION, 41 SEYON ST., BLDG 1, STE 100, WALTHAM
Signature: /s/ Jennifer Carmichael (Attorney in Fact)
Signature date: 25 Sep 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

RGEN transaction

Common Stock

Options Exercise

Transaction value
Shares: +8,404
Change %: +17%
Price: $154.96^*
Shares after: 56,773
Date: 24 Sep 2026
Ownership: Direct
Footnotes: F1

RGEN transaction

Common Stock

Sale

Transaction value: $1,596,760
Shares: -8,404
Change %: -15%
Price: $190.00
Shares after: 48,369
Date: 24 Sep 2026
Ownership: Direct
Footnotes: F1

RGEN transaction

Common Stock

Options Exercise

Transaction value
Shares: +4,542
Change %: +9.4%
Price: $155.38^*
Shares after: 52,911
Date: 24 Sep 2026
Ownership: Direct
Footnotes: F1

RGEN transaction

Common Stock

Sale

Transaction value: $862,980
Shares: -4,542
Change %: -8.6%
Price: $190.00
Shares after: 48,369
Date: 24 Sep 2026
Ownership: Direct
Footnotes: F1

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

RGEN transaction Derivative

Stock Option (Right to Buy)

Options Exercise

Transaction value
Shares: -8,404
Change %: -40%
Price: $0.000000^*
Shares after: 12,607
Date: 24 Sep 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 8,404
Exercise price: $154.96
Footnotes: F1, F2

RGEN transaction Derivative

Stock Option (Right to Buy)

Options Exercise

Transaction value
Shares: -4,542
Change %: -33%
Price: $0.000000^*
Shares after: 9,085
Date: 24 Sep 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 4,542
Exercise price: $155.38
Footnotes: F1, F3

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 3 footnotes

Footnote 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.

Footnote 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.

Footnote F3

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