Gregory K. Chow - 23 Dec 2025 Form 4 Insider Report for SUTRO BIOPHARMA, INC. (STRO)

Role: CFO
Signature: /s/ David Pauling as attorney-in-fact
Issuer symbol: STRO
Transactions as of: 23 Dec 2025
Net transactions value: $0
Form type: 4
Filing time: 29 Dec 2025, 16:47:42 UTC
Previous filing: 16 Oct 2025
Next filing: 03 Mar 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Chow Gregory K.	CFO	C/O SUTRO BIOPHARMA, INC., 111 OYSTER POINT BOULEVARD, SOUTH SAN FRANCISCO	/s/ David Pauling as attorney-in-fact	29 Dec 2025	0001761333

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	STRO	Stock Option (right to buy)	Award	$0	+8,200		$0.000000	8,200	23 Dec 2025	Common Stock	8,200	$10.38	Direct	F1

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	1/48 of the total option award shall vest monthly, subject to the reporting person's continued service to the issuer on each vesting date, with the first tranche vesting on January 23, 2026.