Foresite Capital and Director Tananbaum Invest $10.6M in Alumis Stock
ALMS has more than doubled off its 52-week low of $2.76.
Summary
Foresite Capital, a significant institutional investor, and director James B. Tananbaum, increased their stake in Alumis Inc. by approximately $10.6 million through recent open market purchases and participation in a follow-on offering.
Key Events · Ownership and Investor Activity · ALMS
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Significant Insider/Institutional Purchases
Foresite Capital and director James B. Tananbaum acquired approximately $10.6 million worth of Alumis Inc. common stock.
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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.
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Open Market Acquisitions
An additional $3.6 million in shares were acquired through open market purchases in November 2025.
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Increased Beneficial Ownership
The reporting persons collectively hold 14.1% of Alumis Inc.'s common stock.
Analysis · ALMS · Life Sciences
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.
How filings like this one have moved
In the 30 days to Sep 11, 2026, 35.8% of the 1706 measured filings Wiseek scored 8 moved their stock by 5% or more by the next session's close. The median move was -0.10%. These are measured outcomes after filings of this importance, not a forecast for this one.
Measured one observation per ticker per day, after exclusions. Current figures: Filing Impact Tracker · open dataset
At the time of this filing, ALMS was trading at $21.08 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $2.6B. The 52-week trading range was $2.76 to $22.30. This filing was assessed with positive market sentiment and an importance score of 8 out of 10.