MATSUI CONNIE 4

What Happened
Connie Matsui, a director of Sutro Biopharma (STRO), was granted a derivative award on 2026-06-05 for 10,000 shares at $0.00 (reported as an award/grant). This is a stock option-style award (no cash paid at grant) that gives the right to acquire 10,000 shares subject to vesting and exercise terms.

Key Details

• Transaction date: June 5, 2026; Filing date: June 9, 2026 (timely filed within the Form 4 deadline).
• Grant: 10,000-share derivative award reported at $0.00. Transaction code: A (award/grant).
• Vesting: 8.33% of the award vests monthly beginning July 5, 2026; fully vested and exercisable on the earlier of the issuer’s 2027 annual meeting or June 5, 2027. (See footnote.)
• Shares owned after the transaction: not specified in this filing.
• No sale or immediate cashless exercise reported — this is a forward-looking option award, not an executed sale or purchase.

Context
This filing documents a director equity award (a common form of compensation) rather than a market purchase or sale. Such grants do not immediately change market ownership and are contingent on continued service and vesting; they do not necessarily indicate near-term buying or selling by the insider.