Violetta Hughes - 05 Mar 2026 Form 4 Insider Report for REPLIGEN CORP (RGEN)

Reporting relationship: CHIEF ACCOUNTING OFFICER
Issuer ticker: RGEN
Reported as of: 05 Mar 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 02 Sep 2026, 16:18:30 UTC
Prior SEC filing: 04 Sep 2025
Source filing: View source filing
Reporting owner signature: /s/ Meghan Stapleton (Attorney in Fact)

Key filing fact

Violetta Hughes filed Form 4 for REPLIGEN CORP (RGEN) on 02 Sep 2026.

Key facts

This page summarizes Violetta Hughes's Form 4 filing for REPLIGEN CORP (RGEN).
2 reported transactions and 0 derivative rows are listed below.
Accepted by SEC: 02 Sep 2026, 16:18.

Change

Previous filing in this sequence was filed on 04 Sep 2025.
Current net transaction value: $0.

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 0001991429 Primary reporting owner

Hughes Violetta

Relationship: CHIEF ACCOUNTING OFFICER
Address: C/O REPLIGEN CORPORATION, 41 SEYON ST., BLDG 1, STE 100, WALTHAM
Signature: /s/ Meghan Stapleton (Attorney in Fact)
Signature date: 02 Sep 2026

Reported non-derivative transactions

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

RGEN transaction

Common Stock

Award

Transaction value
Shares: +2,466
Change %: +60%
Price: $0.000000^*
Shares after: 6,608
Date: 05 Mar 2026
Ownership: Direct
Footnotes: F1

RGEN transaction

Common Stock

Tax liability

Transaction value
Shares: -277
Change %: -4.2%
Price: $170.02^*
Shares after: 6,331
Date: 01 Sep 2026
Ownership: Direct
Footnotes: F2

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

Ms. Hughes was awarded 2,466 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of Repligen Corporation's Common Stock. The restricted stock units vest in equal annual installments over a four-year period beginning on the first anniversary of the grant date. The restricted stock units may be settled only by delivering shares of Repligen Corporation's Common Stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

Footnote F2

Represents the number of shares withheld by the Issuer to satisfy the tax withholding obligations of the reporting person that arose upon the release of restricted stock units.