Foresite funds boost Alumis (ALMS) stake with open-market buys
Rhea-AI Filing Summary
Alumis Inc. (ALMS) received a series of insider share purchases by Foresite-affiliated funds and entities whose managing member, James B. Tananbaum, serves as a director of the company. Between 11/17/2025 and 11/19/2025, these reporting persons purchased a combined 507,874 shares of Alumis common stock in open-market transactions at prices ranging from $5.60 to $6.56 per share.
After these transactions, the reporting persons report indirect beneficial ownership of several large blocks of Alumis stock, including 4,247,670 shares held by Foresite Capital Opportunity Fund V, L.P. and 5,584,889 shares held by Foresite Capital Fund VI, L.P., along with additional stakes held by related funds and co-investment vehicles as detailed in the footnotes.
Positive
- None.
Negative
- None.
Insights
Significant affiliated holder increased indirect stake in Alumis through open-market purchases, reinforcing long-term exposure via multiple Foresite investment vehicles.
The filing shows affiliated entities of Foresite, led by James B. Tananbaum, a director and 10% owner, buying Alumis Common Stock in the open market. Between
All reported holdings are marked as indirect (I), with detailed footnotes explaining which Foresite fund or vehicle owns each block and which management entity has voting and dispositive power. The reporting persons explicitly disclaim acting as a group and, except for the direct fund owners, disclaim beneficial ownership beyond their economic interest. This structure means control and economics sit across Opportunity Fund V, Fund V, Fund VI, Labs Co-Invest, Labs Fund I and Labs Affiliates, all linked by overlapping management.
From a monitoring perspective, this Form 4 signals increased exposure rather than reduction, and it confirms that these affiliated vehicles collectively hold several million Alumis shares (for example, 4,247,670, 5,584,889, 1,960,337, and 1,176,470 share blocks). The timing on
Insider Trade Summary
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Purchase | Common Stock | 190,500 | $6.56 | $1.25M |
| Purchase | Common Stock | 117,374 | $6.19 | $727K |
| Purchase | Common Stock | 50,000 | $5.60 | $280K |
| Purchase | Common Stock | 150,000 | $5.59 | $839K |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
| holding | Common Stock | -- | -- | -- |
Footnotes (1)
- The shares are held of record by Foresite Capital Opportunity Fund V, L.P. ("Opportunity Fund V"). Foresite Capital Opportunity Management V, LLC ("FCOM V") is the general partner of Opportunity Fund V and may be deemed to have sole voting and dispositive power over such shares. James B. Tananbaum ("Tananbaum"), the managing member of FCOM V, may be deemed to have sole voting and dispositive power over such shares. Each of the Reporting Persons disclaims the existence of a "group", as defined in Rule 13d-5 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and, other than Opportunity Fund V, disclaims beneficial ownership of the shares held by Opportunity Fund V, except to the extent of such person's pecuniary interest in such securities. The shares are held of record by Foresite Capital Fund VI, L.P. ("Fund VI"). Foresite Capital Management VI, LLC ("FCM VI") is the general partner of Fund VI and may be deemed to have sole voting and dispositive power over such shares. Tananbaum, the managing member of FCM VI, may be deemed to have sole voting and dispositive power over such shares. Each of the Reporting Persons disclaims the existence of a "group", as defined in Rule 13d-5 of the Exchange Act, and, other than Fund VI, disclaims beneficial ownership of the shares held by Fund VI, except to the extent of such person's pecuniary interest in such securities. The shares are held of record by Foresite Capital Fund V, L.P. ("Fund V"). Foresite Capital Management V, LLC ("FCM V") is the general partner of Fund V and may be deemed to have sole voting and dispositive power over such shares. Tananbaum, the managing member of FCM V, may be deemed to have sole voting and dispositive power over such shares. Each of the Reporting Persons disclaims the existence of a "group", as defined in Rule 13d-5 of the Exchange Act, and, other than Fund V, disclaims beneficial ownership of the shares held by Fund V, except to the extent of such person's pecuniary interest in such securities. The shares are held of record by Labs Co-Invest V, LLC ("Labs Co-Invest"). FCM V is the managing member of Labs Co-Invest and may be deemed to have sole voting and dispositive power over such shares. Tananbaum, the managing member of FCM V, may be deemed to have sole voting and dispositive power over such shares. Each of the Reporting Persons disclaims the existence of a "group", as defined in Rule 13d-5 of the Exchange Act, and, other than Labs Co-Invest, disclaims beneficial ownership of the shares held by Labs Co-Invest, except to the extent of such person's pecuniary interest in such securities. The shares are held of record by Foresite Labs Fund I, L.P. ("Labs Fund I"). Foresite Labs Management I, LLC ("FLM I") is the general partner of Labs Fund I and may be deemed to have sole voting and dispositive power over such shares. Tananbaum, the managing member of FLM I, may be deemed to have sole voting and dispositive power over such shares. Each of the Reporting Persons disclaims the existence of a "group", as defined in Rule 13d-5 of the Exchange Act, and, other than Labs Fund I, disclaims beneficial ownership of the shares held by Labs Fund I, except to the extent of such person's pecuniary interest in such securities. The shares are held of record by Foresite Labs Affiliates 2021, LLC ("Labs Affiliates"). Foresite Labs, LLC ("Labs") is the managing member of Labs Affiliates and may be deemed to have sole voting and dispositive power over such shares. Tananbaum, a manager of Labs, may be deemed to share voting and dispositive power over such shares. Each of the Reporting Persons disclaims the existence of a "group", as defined in Rule 13d-5 of the Exchange Act, and, other than Lab Affiliates, disclaims beneficial ownership of the shares held by Labs Affiliates, except to the extent of such person's pecuniary interest in such securities.
FAQ
What did the Form 4 filing report for Alumis Inc. (ALMS)?
The Form 4 reports that Foresite-affiliated funds and entities, whose managing member James B. Tananbaum is a director of Alumis Inc., purchased Alumis common stock in open-market transactions and updated their indirect beneficial ownership positions.
Who are the main reporting entities involved in this Alumis (ALMS) Form 4?
The reporting entities include Foresite Capital Opportunity Fund V, L.P., Foresite Capital Fund VI, L.P., Foresite Capital Fund V, L.P., Labs Co-Invest V, LLC, Foresite Labs Fund I, L.P., and Foresite Labs Affiliates 2021, LLC, along with their respective general partners and management companies.
Do the reporting persons claim group status or full beneficial ownership of all Alumis (ALMS) shares held by the funds?
The reporting persons state that they disclaim the existence of a "group" as defined in Rule 13d-5 and, other than the specific fund or entity that directly holds the shares, they disclaim beneficial ownership except to the extent of their pecuniary interest.
What is James B. Tananbaum’s role in relation to Alumis (ALMS) and the reporting entities?
James B. Tananbaum is identified as a director of Alumis Inc. and serves as managing member or manager of several Foresite-related general partners and management companies that may be deemed to have voting and dispositive power over the reported Alumis shares.