Gregory K. Chow - 02 Jun 2026 Form 4 Insider Report for SUTRO BIOPHARMA, INC. (STRO)

Reporting relationship: CFO
Issuer ticker: STRO
Reported as of: 02 Jun 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 02 Jun 2026, 16:16:04 UTC
Prior SEC filing: 03 Mar 2026
Source filing: View source filing
Reporting owner signature: /s/ David Pauling as attorney-in-fact

Key filing fact

Gregory K. Chow filed Form 4 for SUTRO BIOPHARMA, INC. (STRO) on 02 Jun 2026.

Key facts

This page summarizes Gregory K. Chow's Form 4 filing for SUTRO BIOPHARMA, INC. (STRO).
2 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 02 Jun 2026, 16:16.

Change

Previous filing in this sequence was filed on 03 Mar 2026.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001761333 Primary reporting owner

Chow Gregory K.

Relationship: CFO
Address: C/O SUTRO BIOPHARMA, INC., 111 OYSTER POINT BOULEVARD, SOUTH SAN FRANCISCO
Signature: /s/ David Pauling as attorney-in-fact
Signature date: 02 Jun 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

STRO transaction

Common Stock

Options Exercise

Transaction value
Shares: +2,500
Change %: +112%
Price: $0.000000^*
Shares after: 4,725
Date: 02 Jun 2026
Ownership: Direct
Footnotes: F1, F2

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

STRO transaction Derivative

Restricted Stock Units (RSUs)

Options Exercise

Transaction value
Shares: -2,500
Change %: -25%
Price: $0.000000^*
Shares after: 7,500
Date: 02 Jun 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 2,500
Exercise price
Footnotes: F3, F4

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 4 footnotes

Footnote F1

For avoidance of doubt, the reporting person elected to satisfy tax withholding liabilities in cash in lieu of withholding shares.

Footnote F2

The reported total includes 250 shares of Common Stock acquired by the reporting person in one or more transactions with the Issuer pursuant to its employee stock purchase plan, which transactions are exempt pursuant to Rules 16a3(f)(1)(i)(B) and 16b3(c).

Footnote F3

Each RSU represents a contingent right to receive one (1) share of the Issuer's Common Stock upon settlement.

Footnote F4

The award vested or vests annually as to 1/4th of the total award, subject to the reporting person's continued service to the Issuer on each vesting date, with the first tranche vested on June 2, 2026.