Form 4: Sutro Biopharma Director Granted Stock Options

Sutro Biopharma director Jon Marc Wigginton was granted 1,500 stock options with an exercise price of $10.38, vesting monthly over six months.

Summary

• Jon Marc Wigginton, a director at Sutro Biopharma, Inc. (STRO), was granted 1,500 stock options.
• The stock options have an exercise price of $10.38 per share.
• The transaction date for the option grant was December 23, 2025.
• The options will vest as to 16.67% of the total award monthly, subject to Mr. Wigginton's continued service to the issuer.
• The first tranche of options is scheduled to vest on January 23, 2026.
• The options have an expiration date of December 23, 2035.
• Following this reported transaction, Mr. Wigginton beneficially owns 1,500 derivative securities (stock options).
• A Limited Power of Attorney was executed on October 6, 2025, authorizing Regina Cheng, David Pauling, and Gregory Chow to execute and file Forms 3, 4, and 5 on behalf of Mr. Wigginton.

Sentiment

Score: 6

Explanation: The grant of stock options to a director is generally a positive event as it aligns the director's interests with the company's long-term performance and shareholder value. It is a standard form of compensation and incentive.

Positives

• The grant of 1,500 stock options aligns the director's financial interests with the long-term performance and shareholder value of Sutro Biopharma.
• The monthly vesting schedule incentivizes continued service and commitment from the director to the company.

Risks

• The ultimate value of the stock options is contingent upon the future market price of Sutro Biopharma's common stock, which may fluctuate.
• The vesting of the options is conditional on Jon Marc Wigginton's continued service to Sutro Biopharma, Inc.

Future Outlook

The stock options are subject to a monthly vesting schedule over approximately six months, with the first tranche vesting on January 23, 2026, contingent on the director's continued service.

Management Comments

• Jon Marc Wigginton granted a Limited Power of Attorney to Regina Cheng, David Pauling, and Gregory Chow to execute and file Forms 3, 4, and 5 on his behalf, affirming commitment to regulatory compliance.

Industry Context

This filing represents a routine insider transaction, specifically an equity grant to a director, which is a common practice in the biopharmaceutical industry to align management and director incentives with company performance and shareholder interests.

Corporate Governance

Stakeholder Impact

• Shareholders: The option grant aligns the director's interests with shareholder value, potentially fostering decisions that benefit long-term stock performance.
• Employees: No direct impact on general employees is indicated by this specific filing.

Next Steps

• The stock options will continue to vest monthly at 16.67% of the total award, subject to the director's continued service.

Key Dates

Keywords

Sutro Biopharma, STRO, Stock Options, Insider Transaction, Director Compensation, Equity Grant, SEC Form 4, Biopharma