SCHEDULE: Atlas Venture Funds File Schedule 13G for Day One Biopharmaceuticals

Atlas Venture Fund XI, L.P. and related entities have filed a Schedule 13G, reporting 0% beneficial ownership of Day One Biopharmaceuticals, Inc. common stock as of March 31, 2026.

Summary

• This filing is an amendment to a Schedule 13G, indicating a joint filing agreement among several Atlas Venture entities.
• The reporting entities include Atlas Venture Fund XI, L.P., Atlas Venture Associates XI, L.P., Atlas Venture Associates XI, LLC, Atlas Venture Opportunity Fund I, L.P., Atlas Venture Associates Opportunity I, L.P., Atlas Venture Associates Opportunity I, LLC, Atlas Venture Opportunity Fund II, L.P., Atlas Venture Associates Opportunity II, L.P., and Atlas Venture Associates Opportunity II, LLC.
• The filing pertains to the Common Stock of Day One Biopharmaceuticals, Inc.
• As of March 31, 2026, the date requiring this filing, the reporting persons collectively beneficially owned 0 shares of common stock, representing 0% of the class.
• The entities are organized in Delaware and are classified as investment advisors (PN) or other (OO) for reporting purposes.
• The filing certifies that the securities were not acquired or held for the purpose of influencing or changing the control of the issuer.

Sentiment

Score: 2

Explanation: StockSavvy.ai views this filing as neutral to slightly negative, as it indicates a lack of significant current investment or control by a major venture capital firm in the company.

Negatives

• The reporting entities hold zero shares of Day One Biopharmaceuticals, Inc. common stock, indicating no current investment or control interest.

Future Outlook

No forward-looking statements or guidance are present in this filing, as it solely concerns current ownership status.

Industry Context

StockSavvy.ai notes that Schedule 13G filings are typically made by institutional investors who acquire beneficial ownership of more than 5% of a class of a company's registered equity securities. The absence of any reported ownership by Atlas Venture entities in this filing suggests they do not currently meet this threshold for Day One Biopharmaceuticals.

Stakeholder Impact

• Shareholders: The filing indicates no current significant ownership stake by Atlas Venture entities, which may influence perceptions of institutional support or future investment.

Key Dates

Keywords

Schedule 13G, Day One Biopharmaceuticals, Atlas Venture, SEC Filing, Beneficial Ownership, Investment Advisor, Securities Exchange Act