Olivier Loeillot, Chief Executive Officer and Director of Repligen Corporation, filed a statement of changes in beneficial ownership with the SEC on September 8, 2026, covering two transactions in Repligen common stock that occurred on September 3 and September 4, 2026.

Key Highlights

  • Tax withholding disposition: 2,842 shares of common stock were withheld by Repligen on September 3, 2026, at $169.61 per share to satisfy tax obligations arising from the release of restricted stock units.
  • Open-market sale: 3,035 shares were sold on September 4, 2026, at $165.90 per share pursuant to a Rule 10b5-1 trading plan.
  • 10b5-1 plan adoption date: The trading plan governing the September 4 sale was adopted by Loeillot on August 19, 2025, according to the filing.
  • Remaining ownership: Following both transactions, Loeillot directly held 48,369 shares of Repligen common stock.
  • Filer identity: The filing was signed by Jennifer Carmichael as Attorney in Fact on September 8, 2026.

Repligen CEO's Share Transactions: Withholding, Sale, and Remaining Position

According to the filing, Olivier Loeillot serves as both Chief Executive Officer and a Director of Repligen Corporation, which trades on NASDAQ:RGEN. The first transaction, coded "F," involved 2,842 shares disposed of on September 3, 2026, at a price of $169.61 per share. The filing notes that this figure "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." Following this transaction, Loeillot's directly held position stood at 51,404 shares.

The second transaction, coded "S," involved the open-market sale of 3,035 shares on September 4, 2026, at $165.90 per share. The filing states that "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." Repligen Corporation, headquartered in Waltham, Massachusetts, is a bioprocessing technology company. After the September 4 sale, Loeillot's direct beneficial ownership totaled 48,369 shares of common stock, with all reported holdings classified as direct ownership and no indirect holdings noted in the filing.

What Was Disclosed

The filing reported two disposals of Repligen common stock by CEO Olivier Loeillot: a tax-related share withholding of 2,842 shares at $169.61 on September 3, 2026, and a plan-governed sale of 3,035 shares at $165.90 on September 4, 2026, leaving a direct holding of 48,369 shares.