Douglass Brian Robb 4

What Happened
Brian Robb, Chief Product Officer of Repligen Corp (RGEN), had 221 shares withheld by the company to satisfy tax withholding obligations when restricted stock units vested. The withholding was reported at $124.97 per share, totaling $27,618. This was not an open-market sale but a tax-withholding action tied to an equity award.

Key Details

• Transaction date: 2026-03-02; Filing date: 2026-03-03 (timely filing).
• Withheld shares: 221 at $124.97 per share; total value $27,618.
• Shares owned after transaction: Not specified in the Form 4 filing.
• Footnote: F1 — shares were withheld by the issuer to satisfy tax withholding on the release of restricted stock units.
• Transaction code: F (tax withholding), not a purchase (P) or sale (S) in the open market.

Context
Withholding shares to cover taxes on RSU vesting is a routine administrative action and does not necessarily signal bullish or bearish insider intent. It’s effectively a cashless cover of tax liability rather than a discretionary sale.