Cole Pinnow - 17 Dec 2025 Form 4 Insider Report for Cogent Biosciences, Inc. (COGT)

Role: Chief Commercial Officer
Signature: /s/ Evan D. Kearns, Attorney-in-Fact
Issuer symbol: COGT
Transactions as of: 17 Dec 2025
Net transactions value: -$3,739,860
Form type: 4
Filing time: 19 Dec 2025, 16:01:08 UTC
Previous filing: 27 Jan 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Pinnow Cole	Chief Commercial Officer	C/O COGENT BIOSCIENCES, INC., 275 WYMAN STREET, 3RD FLOOR, WALTHAM	/s/ Evan D. Kearns, Attorney-in-Fact	19 Dec 2025	0002024135

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	COGT	Common Stock	Award	$0	+50,000	+105%	$0.000000	97,450	17 Dec 2025	Direct	F1, F2
transaction	COGT	Common Stock	Award	$0	+214,000	+220%	$0.000000	311,450	17 Dec 2025	Direct	F3
transaction	COGT	Common Stock	Tax liability	$3,739,860	-94,800	-30%	$39.45	216,650	17 Dec 2025	Direct	F4, F5

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	COGT	Stock Option (Right to Buy)	Award	$0	+65,000		$0.000000	65,000	17 Dec 2025	Common Stock	65,000	$39.45	Direct	F6

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Award of Restricted Stock Units ("RSUs") under the Issuer's 2018 Stock Option and Incentive Plan. The RSUs shall vest with respect to 1/4th of the underlying shares on each anniversary of the grant date, such that the RSUs are fully vested on the fourth anniversary of the grant date, subject to the Reporting Person's continuing service with the Issuer through such dates.
F2	Includes an aggregate of 1,602 shares of common stock acquired by the Reporting Person under the Issuer's 2018 Employee Stock Purchase Plan on June 30, 2025.
F3	Represents acquisition of shares of common stock in connection with the vesting of a performance-based RSU award granted in February 2023 (the "2023 PSUs").
F4	Represents shares surrendered to the Issuer by the Reporting Person to pay required tax withholdings in connection with the vesting of the 2023 PSUs.
F5	Includes previously reported shares of common stock underlying RSUs granted to the Reporting Person, which are subject to certain vesting conditions.
F6	This stock option shall vest in equal monthly installments over a four year period, subject to the Reporting Person's continuing service to the Issuer through such dates.