BELVIN MARCIA 4

What Happened

• Marcia Belvin, SVP and Chief Scientific Officer of CytomX Therapeutics (CTMX), sold 31,492 shares on 2026-03-17 at $6.42 per share, generating proceeds of $202,273. This was a sale (not a purchase) and was reported on a Form 4 filed 2026-03-19.

Key Details

• Transaction date and price: 2026-03-17 at $6.42 per share.
• Total proceeds: $202,273 for 31,492 shares.
• Purpose/footnote: The filing states the shares were sold solely to satisfy tax or other government withholding obligations in connection with RSU vesting (Footnote F1).
• Holdings noted: Filing indicates holdings include 135,833 RSUs (Footnote F2).
• Timeliness: Form 4 was filed on 2026-03-19 (covers the 3/17 transaction) and appears to be filed within the required reporting window.

Context

• This was a withholding-related sale tied to RSU vesting (a routine, administrative transaction) rather than a discretionary sell for investment reasons. Such tax-withholding sales are common and do not necessarily indicate management sentiment about the company’s stock.