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.

Insights

Equity Ownership Analyst

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 11/17/2025 and 11/19/2025, they purchased a total of 507,874 shares at prices between $5.59 and $6.56 (plus an initial block at $5.6). These transactions increased one indirect position to 2,542,003 shares, with several other large indirect blocks reported across different funds and entities.

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 11/17/2025–11/19/2025 provides a clear reference point for when this additional capital was committed. Future ownership reports and any subsequent Form 4 or Schedule 13 filings will show whether this accumulation trend continues or stabilizes.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Foresite Capital Management VI LLC

(Last) (First) (Middle)

900 LARKSPUR LANDING CIRCLE

SUITE 150

(Street)

LARKSPUR CA 94939

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
ALUMIS INC. [ ALMS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
11/17/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	11/17/2025		P		50,000	A	$5.6	2,084,129	I	See Footnote(1)
Common Stock	11/17/2025		P		150,000	A	$5.59	2,234,129	I	See Footnote(1)
Common Stock	11/18/2025		P		117,374	A	$6.19	2,351,503	I	See Footnote(1)
Common Stock	11/19/2025		P		190,500	A	$6.56	2,542,003	I	See Footnote(1)
Common Stock								4,247,670	I	See Footnote(2)
Common Stock								5,584,889	I	See Footnote(3)
Common Stock								194,459	I	See Footnote(4)
Common Stock								1,960,337	I	See Footnote(5)
Common Stock								1,176,470	I	See Footnote(6)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person^*

Foresite Capital Management VI LLC

(Last) (First) (Middle)

900 LARKSPUR LANDING CIRCLE

SUITE 150

(Street)

LARKSPUR CA 94939

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Foresite Capital Management V, LLC

(Last) (First) (Middle)

900 LARKSPUR LANDING CIRCLE

SUITE 150

(Street)

LARKSPUR CA 94939

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Foresite Capital Fund V, L.P.

(Last) (First) (Middle)

900 LARKSPUR LANDING CIRCLE

SUITE 150

(Street)

LARKSPUR CA 94939

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Foresite Capital Opportunity Management V, LLC

(Last) (First) (Middle)

900 LARKSPUR LANDING CIRCLE

SUITE 150

(Street)

LARKSPUR CA 94939

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Foresite Capital Opportunity Fund V, L.P.

(Last) (First) (Middle)

900 LARKSPUR LANDING CIRCLE

SUITE 150

(Street)

LARKSPUR CA 94939

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Foresite Capital Fund VI LP

(Last) (First) (Middle)

900 LARKSPUR LANDING CIRCLE

SUITE 150

(Street)

LARKSPUR CA 94939

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Labs Co-Invest V, LLC

(Last) (First) (Middle)

900 LARKSPUR LANDING CIRCLE

SUITE 150

(Street)

LARKSPUR CA 94939

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Foresite Labs Management I, LLC

(Last) (First) (Middle)

900 LARKSPUR LANDING CIRCLE

SUITE 150

(Street)

LARKSPUR CA 94939

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Foresite Labs Fund I, L.P.

(Last) (First) (Middle)

900 LARKSPUR LANDING CIRCLE

SUITE 150

(Street)

LARKSPUR CA 94939

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.

Remarks:

This Form 4 is one of three Form 4s filed on the date hereof in respect of these transactions. The Reporting Persons for the other Form 4s are Tananbaum, Labs Affiliates and Labs.

	FORESITE CAPITAL MANAGEMENT V, LLC, By: /s/ James B. Tananbaum, Managing Member	11/19/2025
	FORESITE CAPITAL FUND V, L.P., By: Foresite Capital Management V, LLC, Its: General Partner, By: /s/ James B. Tananbaum, Managing Member	11/19/2025
	FORESITE CAPITAL OPPORTUNITY MANAGEMENT V, LLC, By: /s/ James B. Tananbaum, Managing Member	11/19/2025
	FORESITE CAPITAL OPPORTUNITY FUND V, L.P., By: Foresite Capital Opportunity Management V, LLC, Its: General Partner, By: /s/ James B. Tananbaum, Managing Member	11/19/2025
	FORESITE CAPITAL MANAGEMENT VI, LLC, By: /s/ James B. Tananbaum, Managing Member	11/19/2025
	FORESITE CAPITAL FUND VI, L.P., By: Foresite Capital Management VI, LLC, Its: General Partner, By: /s/ James B. Tananbaum, Managing Member	11/19/2025
	LABS CO-INVEST V, LLC, By: Foresite Capital Management V, LLC, Its: Managing Member, By: /s/ James B. Tananbaum, Managing Member	11/19/2025
	FORESITE LABS MANAGEMENT I, LLC, By: /s/ James B. Tananbaum, Managing Member	11/19/2025
	FORESITE LABS FUND I, L.P., By: Foresite Labs Management I, LLC, Its: General Partner, By: /s/ James B. Tananbaum, Managing Member	11/19/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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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.

How many Alumis (ALMS) shares were purchased in these insider transactions?

The reported transactions show purchases totaling 507,874 shares of Alumis common stock across several trades on 11/17/2025, 11/18/2025, and 11/19/2025.

At what prices were the Alumis (ALMS) shares bought by the reporting persons?

The purchases of Alumis common stock were made at prices of $5.60, $5.59, $6.19, and $6.56 per share, as listed for each transaction date.

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.

How many Alumis (ALMS) shares are indirectly owned by key Foresite funds after these transactions?

Following the reported transactions, the filing shows indirect beneficial ownership of 4,247,670 shares by Foresite Capital Opportunity Fund V, L.P. and 5,584,889 shares by Foresite Capital Fund VI, L.P., with additional holdings reported by other related entities.

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.