SCHEDULE: Vanguard Group Amends Syndax Pharma Stake

The Vanguard Group filed an amended Schedule 13G, disclosing a 7.16% beneficial ownership in Syndax Pharmaceuticals Inc. common stock as of December 31, 2025.

Summary

• The Vanguard Group reported beneficial ownership of 6,230,334 shares of Syndax Pharmaceuticals Inc. common stock.
• This represents 7.16% of the class of securities.
• The filing date was January 30, 2026, with the event date being December 31, 2025.
• The Vanguard Group holds shared voting power over 702,989 shares and shared dispositive power over 6,230,334 shares.
• An internal realignment occurred on January 12, 2026, where The Vanguard Group, Inc. ceased performing portfolio management and proxy voting services.
• Certain subsidiaries or business divisions of Vanguard are expected to report beneficial ownership separately in the future.

Sentiment

Score: 5

Explanation: StockSavvy.ai views this as a neutral filing, primarily an administrative update on a significant passive ownership stake by a major institutional investor, with no direct impact on Syndax Pharmaceuticals Inc.'s operational or financial performance.

Positives

• The Vanguard Group, a major institutional investor, maintains a significant beneficial ownership of 7.16% in Syndax Pharmaceuticals Inc., indicating continued passive investment interest.

Negatives

• No direct negatives concerning Syndax Pharmaceuticals Inc.'s operations or financial health are disclosed in this ownership filing.

Future Outlook

The Vanguard Group, Inc. anticipates that certain subsidiaries or business divisions will report beneficial ownership separately (on a disaggregated basis) from The Vanguard Group, Inc. in reliance on SEC Release No. 34-39538, following an internal realignment on January 12, 2026.

Management Comments

• On January 12, 2026, The Vanguard Group, Inc. went through an internal realignment. As of that date, The Vanguard Group, Inc. no longer performs portfolio management services or administers proxy voting.
• In accordance with SEC Release No. 34-39538 (January 12, 1998), The Vanguard Group, Inc. anticipates that certain subsidiaries or business divisions of subsidiaries of The Vanguard Group, Inc., that currently have, or are deemed to have, beneficial ownership with The Vanguard Group, Inc., will report beneficial ownership separately (on a disaggregated basis) from The Vanguard Group, Inc. in reliance on such release.
• These subsidiaries and/or business divisions pursue the same investment strategies as previously pursued by The Vanguard Group, Inc. prior to the realignment.

Industry Context

StockSavvy.ai notes that Schedule 13G filings are routine disclosures by passive institutional investors holding more than 5% of a company's stock. Vanguard's continued significant stake in Syndax Pharmaceuticals Inc. indicates its ongoing passive investment in the biotechnology sector, aligning with its broad market index strategies.

Comparison to Industry Standards

• The 7.16% stake held by The Vanguard Group is a substantial passive investment, typical for large index fund managers in publicly traded companies.
• Vanguard's internal realignment and subsequent disaggregated reporting by subsidiaries is a common practice among large asset managers to comply with regulatory requirements and reflect internal operational structures.

Stakeholder Impact

• Shareholders: Provides transparency regarding a significant institutional holder's stake and its internal reporting changes.
• Investment Professionals: Offers insight into Vanguard's passive investment strategy and its internal organizational structure for reporting purposes.

Next Steps

• The Vanguard Group's subsidiaries or business divisions are anticipated to report beneficial ownership separately from The Vanguard Group, Inc. in future filings.

Key Dates

Keywords

Syndax Pharmaceuticals, Vanguard Group, Common Stock, Schedule 13G, Beneficial Ownership, Institutional Investor, Pharmaceuticals, Biotech