[Form 4] Cullinan Therapeutics, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Lynx1 Capital Management LP and affiliated reporting person Weston Nichols disclosed purchases of Cullinan Therapeutics, Inc. (CGEM) common stock across three days. On 10/08/2025 they bought 556,300 shares at a weighted average price of $6.46, increasing indirect holdings to 7,645,743 shares. On 10/09/2025 they acquired 626,043 shares at a weighted average of $6.6958, bringing holdings to 8,271,786 shares. On 10/10/2025 they purchased 277,298 shares at a weighted average of $7.3617, raising indirect holdings to 8,549,084 shares. The shares are held directly by Lynx1 Master Fund LP, for which Lynx1 Capital Management LP serves as investment manager; the filing disclaims beneficial ownership except to the extent of any pecuniary interest.

Positive

• Material accumulation: 1,459,641 shares acquired over three days indicates meaningful fund-level buying
• Clear disclosure: Filing provides weighted-average prices and entity relationships, aiding transparency

Negative

• Indirect ownership held via Lynx1 Master Fund LP, with disclaimer of beneficial ownership limits clarity on direct economic interest
• No derivative activity reported, so leverage or hedging stance is not disclosed

Insights

Corporate Governance Analyst

Substantial insider-aligned fund purchases increased indirect stake to 8.55M shares.

The purchases occurred over 10/08/2025–10/10/2025 and were executed by Lynx1 entities, with the securities held directly by Lynx1 Master Fund LP. The filing clarifies the investment manager and general partner relationships and includes weighted-average prices for each trading day.

This structure means the trading reflects the fund's activity rather than direct personal buys; monitor subsequent Form 4 filings for any changes in ownership form or additional purchases within the next quarter to assess trend persistence.

Equity Trading Analyst

Average purchase prices rose across three days, suggesting intra-day/market price movement.

The weighted-average prices moved from $6.46 to $6.6958 to $7.3617, indicating upward execution prices during the reported window. Total newly acquired shares equal 1,459,641.

If trading continued, short-term price impact could be observable; watch for additional volume disclosures or updated filings within 30 days that would show follow-on accumulation or disposition.

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^*

Lynx1 Capital Management LP

(Last) (First) (Middle)

D81 CALLE C

STE 301, PMB 1202

(Street)

DORADO PR 00646-2051

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Cullinan Therapeutics, Inc. [ CGEM ]

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)
10/08/2025

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, $0.0001 par value per share ("Common Stock")	10/08/2025		P		556,300	A	$6.46(1)	7,645,743	I	See footnote(2)
Common Stock	10/09/2025		P		626,043	A	$6.6958(3)	8,271,786	I	See footnote(2)
Common Stock	10/10/2025		P		277,298	A	$7.3617(4)	8,549,084	I	See footnote(2)

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^*

Lynx1 Capital Management LP

(Last) (First) (Middle)

D81 CALLE C

STE 301, PMB 1202

(Street)

DORADO PR 00646-2051

(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^*

Nichols Weston

(Last) (First) (Middle)

D81 CALLE C

STE 301, PMB 1202

(Street)

DORADO PR 00646-2051

(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 price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $6.40 to $6.60 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of shares purchased at each separate price within the range set forth herein.

2. The securities to which this filing relates are held directly by Lynx1 Master Fund LP to which Lynx1 Capital Management LP (the "Investment Manager") serves as investment manager. Weston Nichols ("Mr. Nichols") is the sole member of Lynx1 Capital Management GP LLC, the general partner of the Investment Manager. Each of the Investment Manager and Mr. Nichols disclaims beneficial ownership of the securities to which this filing relates for purposes of Section 16 of the Securities and Exchange Act of 1934, as amended, except to the extent of his or its pecuniary interest therein, if any.

3. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $6.60 to $6.90 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares purchased at each separate price within the range set forth herein.

4. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $6.87 to $7.46 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares purchased at each separate price within the range set forth herein.

	Lynx1 Capital Management LP, By: Lynx1 Capital Management GP LLC, its general partner, By: /s/ Weston Nichols, Sole Member	10/10/2025
	/s/ Weston Nichols	10/10/2025
	** 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 Lynx1 report buying in the Form 4 for Cullinan Therapeutics (CGEM)?

They reported acquiring a total of 1,459,641 shares across three purchases on 10/08/2025, 10/09/2025, and 10/10/2025.

How many shares does Lynx1 indirectly own after these purchases?

Indirect holdings increased to 8,549,084 shares following the 10/10/2025 transaction.

At what prices were the CGEM shares purchased?

Reported weighted-average prices were $6.46 on 10/08/2025, $6.6958 on 10/09/2025, and $7.3617 on 10/10/2025.

Who holds the shares and who filed the Form 4?

Shares are held directly by Lynx1 Master Fund LP. The Form 4 was filed by Lynx1 Capital Management LP and signed by Weston Nichols.

Does the filing claim direct beneficial ownership by Weston Nichols?

No. The filing disclaims beneficial ownership by the Investment Manager and Mr. Nichols except to the extent of any pecuniary interest.