SCHEDULE: Affinity Asset Advisors Discloses 8.8% Stake in Sutro Biopharma

Affinity Asset Advisors, LLC and Michael Cho have reported beneficial ownership of 8.8% of Sutro Biopharma, Inc.'s common stock.

Summary

• Affinity Asset Advisors, LLC and Michael Cho, its managing member, have filed an Amendment No. 1 to Schedule 13G regarding their beneficial ownership in Sutro Biopharma, Inc.
• The reporting persons beneficially own 748,382 shares of Sutro Biopharma, Inc. common stock.
• This ownership represents approximately 8.8% of the Issuer's outstanding common stock.
• The percentage is based on 8,519,392 shares of common stock outstanding as of December 3, 2025, as reported in Sutro Biopharma, Inc.'s Form 8-K.
• The securities are held by Affinity Healthcare Fund, LP, with Affinity Asset Advisors, LLC serving as the investment manager.
• As of the filing date, the reporting persons hold sole voting power and sole dispositive power over all 748,382 shares.
• This represents a change from December 31, 2025, when the Fund and Adviser had shared voting and dispositive power over the same number of shares.
• The acquisition of these securities was made in the ordinary course of business and not for the purpose of changing or influencing control of Sutro Biopharma, Inc.

Sentiment

Score: 6

Explanation: StockSavvy.ai views this as a moderately positive signal, as a significant institutional stake suggests confidence in Sutro Biopharma, Inc. without indicating any immediate operational changes or financial performance.

Positives

• A significant 8.8% stake by an investment advisor like Affinity Asset Advisors, LLC could be interpreted as a vote of confidence in Sutro Biopharma, Inc.'s long-term prospects.

Future Outlook

NA

Industry Context

StockSavvy.ai notes that institutional ownership disclosures, such as this Schedule 13G, provide transparency into significant investment positions in public companies. For a biopharma company like Sutro Biopharma, Inc., a substantial stake by an investment advisor specializing in healthcare can signal a perceived long-term value or strategic interest in the company's pipeline or market position.

Stakeholder Impact

• Shareholders: The disclosure of a significant institutional investor holding an 8.8% stake may instill confidence and potentially attract further institutional interest.
• Management: Awareness of a large institutional holder may influence strategic decisions, though the filing explicitly states the stake is not for control purposes.

Key Dates

Recommendation

The filing indicates a significant institutional investment in Sutro Biopharma, Inc., which is generally a positive sign of confidence. However, a Schedule 13G filing primarily discloses ownership and does not provide new operational or financial performance data to warrant a 'buy' or 'sell' recommendation. It suggests that a seasoned investor would likely maintain their current position, awaiting further fundamental updates from the company.

Keywords

Sutro Biopharma, Inc., Affinity Asset Advisors, Michael Cho, Schedule 13G, Beneficial Ownership, Common Stock, Biopharma, Investment Advisor, Institutional Ownership