Ruddy Marcella K. 4

What Happened Marcella K. Ruddy, Chief Medical Officer of Tectonic Therapeutic (TECX), had 2,064 shares withheld by the issuer to satisfy tax withholding in connection with the vesting/settlement of restricted stock units. The withholding occurred at $23.22 per share, resulting in a disposition value of $47,926. This was a tax-withholding withholding (transaction code F), not an open-market sale.

Key Details

• Transaction date: 2026-02-04; withholding price: $23.22 per share; shares withheld/disposed: 2,064; total value: $47,926.
• Nature of transaction: F = shares withheld by issuer to satisfy tax obligations on vested RSUs (per footnote: relates to RSUs granted Feb 4, 2025).
• Shares owned after the transaction: Not disclosed on the filing.
• Filing date: 2026-02-10 (the Form 4 was submitted six days after the transaction; Form 4s are typically due within two business days, so this filing appears to be late).

Context This was a routine tax-withholding action tied to RSU vesting — effectively a cashless settlement where the company retains shares to cover taxes — and does not necessarily indicate the insider is selling shares into the market. Purchases or open-market sales can be more informative about insider sentiment; withholding to cover tax is a common administrative step.