[Form 4] Tourmaline Bio, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Tourmaline Bio (TRML) disclosed an insider ownership update. A company director reported a Code G transaction on 10/15/2025, indicating a distribution of 522 shares of common stock at $0.

Following the transaction, the reporting person directly holds 515,997 shares. An additional 431,939 shares are listed as indirectly held by KVP Capital, LP. Footnotes state this reflects an in-kind distribution by KVP to a limited partner for no consideration and a change in the form of ownership. The reporting person is associated with KVP’s general partner and disclaims beneficial ownership of KVP-held shares except for any pecuniary interest.

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

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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^*

Castelein Caley

(Last) (First) (Middle)

C/O TOURMALINE BIO, INC.

27 WEST 24TH STREET, SUITE 702

(Street)

NEW YORK NY 10010

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Tourmaline Bio, Inc. [ TRML ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
10/15/2025

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

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

X	Form filed by One Reporting Person
	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	10/15/2025		G		522	D	$0	515,997	D
Common Stock								431,939(1)	I	By KVP Capital, LP(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

Explanation of Responses:

1. Gives effect to in-kind distribution of shares by KVP Capital, LP ("KVP") to its limited partner for no consideration, subsequent to the Reporting Person's most recent filing, which represented a change in the form of the Reporting Person's ownership that was not required to be reported under Section 16.

2. These shares are held by KVP. The Reporting Person is the Managing Member of KVP Capital GP, LLC, the General Partner of KVP and, as such, has sole voting and investment power with respect to the shares held by KVP. The Reporting Person disclaims beneficial ownership of the shares held by KVP except to the extent of his pecuniary interest therein and this report is not an admission that the Reporting Person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.

	/s/ Brad Middlekauff, Attorney-in-Fact	10/17/2025
	** 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 TRML insider report on Form 4?

A director reported a Code G distribution of 522 shares on 10/15/2025 at $0.

How many TRML shares does the reporting person hold directly after the transaction?

Direct holdings are 515,997 shares following the reported transaction.

Are there indirect TRML holdings reported?

Yes. 431,939 shares are indirectly held by KVP Capital, LP, per the filing.

What does Transaction Code G mean here?

The filing notes an in-kind distribution for no consideration, consistent with a Code G transfer.

Does the reporting person claim beneficial ownership of KVP-held shares?

The reporting person disclaims beneficial ownership of KVP-held shares except to the extent of any pecuniary interest.

What explains the change in ownership form?

Footnotes state KVP distributed shares in-kind to a limited partner, reflecting a change in ownership form.