Foresite Capital and Director Tananbaum Invest $10.6M in Alumis Stock

summarizeSummary

This Schedule 13D/A filing reveals that Foresite Capital, a major institutional shareholder, and James B. Tananbaum, a director of Alumis Inc. and managing member of Foresite entities, have significantly increased their beneficial ownership. The group acquired approximately $3.6 million in open market purchases in November 2025 and an additional $7.0 million in the company's follow-on offering on January 8, 2026. These substantial investments, totaling around $10.6 million, demonstrate strong conviction from a key investor and insider, particularly following a period of dilution. The participation in the follow-on offering at $17.00 per share, compared to the current stock price of $21.08, suggests confidence in the company's valuation and future prospects.

check_boxKey Events

• Significant Insider/Institutional Purchases

  Foresite Capital and director James B. Tananbaum acquired approximately $10.6 million worth of Alumis Inc. common stock.

• Follow-on Offering Participation

  The group purchased $7.0 million in shares at $17.00 per share as part of the company's January 8, 2026 follow-on offering.

• Open Market Acquisitions

  An additional $3.6 million in shares were acquired through open market purchases in November 2025.

• Increased Beneficial Ownership

  The reporting persons collectively hold 14.1% of Alumis Inc.'s common stock.

auto_awesomeAnalysis

This Schedule 13D/A filing reveals that Foresite Capital, a major institutional shareholder, and James B. Tananbaum, a director of Alumis Inc. and managing member of Foresite entities, have significantly increased their beneficial ownership. The group acquired approximately $3.6 million in open market purchases in November 2025 and an additional $7.0 million in the company's follow-on offering on January 8, 2026. These substantial investments, totaling around $10.6 million, demonstrate strong conviction from a key investor and insider, particularly following a period of dilution. The participation in the follow-on offering at $17.00 per share, compared to the current stock price of $21.08, suggests confidence in the company's valuation and future prospects.