Young Teresa L. 4

What Happened
Teresa L. Young, EVP & Chief Commercial & Strategy Officer of Seres Therapeutics (MCRB), had 231 restricted stock units convert/settle into common shares on February 15, 2026. To cover taxes tied to the vesting, 75 of those shares were sold in the open market at $8.47 per share for total proceeds of ~$635. Additionally, 231 shares were reported as converted/settled (the filing records 133 and 98-share dispositions at $0, reflecting shares withheld/settled with no cash proceeds).

Key Details

• Transaction date: February 15, 2026; Form 4 filed February 18, 2026 (no late filing indicated).
• Open-market sale: 75 shares at $8.47 each; proceeds reported $635.
• Conversion/settlement (derivative conversion): 231 shares converted/settled; 133 and 98 shares reported as disposed at $0 (reflecting shares withheld/settled).
• Shares owned after the transactions: Not specified in this Form 4 filing.
• Notable footnotes:
  • F1: Each restricted stock unit (RSU) converts to one share.
  • F2: The sale was executed under a Rule 10b5-1 plan (adopted Mar 5, 2023) solely to cover taxes on RSU vesting.
  • F3/F4: RSUs vest on a schedule (25% on prior Feb 15 dates, remainder in 12 equal quarterly installments); RSUs have no expiration.

Context
This activity stems from RSU vesting and routine tax-covering actions rather than an open-market investment decision. The conversion of RSUs to shares followed by a small sale and withholding is common for executives to satisfy tax obligations and does not necessarily indicate a change in insider sentiment.