Julius Knowles - 04 Jun 2025 Form 4 Insider Report for Keros Therapeutics, Inc. (KROS)

Role: Director
Signature: /s/ Keith Regnante, Attorney-in-Fact
Issuer symbol: KROS
Transactions as of: 04 Jun 2025
Net transactions value: $0
Form type: 4
Filing time: 06 Jun 2025, 16:15:23 UTC
Previous filing: 03 Jun 2024
Next filing: 18 Dec 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Knowles Julius	Director	C/O KEROS THERAPEUTICS, INC., 1050 WALTHAM STREET, SUITE 302, LEXINGTON	/s/ Keith Regnante, Attorney-in-Fact	06 Jun 2025	0001808365

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	KROS	Common Stock	Award	$0	+5,250	+441%	$0.000000	6,441	04 Jun 2025	Direct	F1
holding	KROS	Common Stock						341,574	04 Jun 2025	See footnote	F2
holding	KROS	Common Stock						232,727	04 Jun 2025	See footnote	F3

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	KROS	Stock Option (right to buy)	Award	$0	+10,500		$0.000000	10,500	04 Jun 2025	Common Stock	10,500	$14.82	Direct	F4

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

Explanation of Responses:

Id	Content
F1	Represents a restricted stock unit ("RSU") award. The RSUs fully vest on the earlier of (A) June 4, 2026 and (B) the date of the Issuer's 2026 annual meeting of stockholders, subject to the Reporting Person continuing to provide service through each such date.
F2	The securities are held by Partners Innovation Fund, LLC ("PIF I"). Partners Innovation Fund, LLC ("Partners GP I") is the ultimate general partner of PIF I. The Reporting Person, a member of the board of directors of the Issuer, is a partner of Partners GP I and as a result, may be deemed to share voting and investment power with respect to the shares held by PIF I.
F3	The securities are held by Partners Innovation Fund II, L.P. ("PIF II"). Partners Innovation Fund II, LLC ("Partners GP II") is the ultimate general partner of PIF II. The Reporting Person, a member of the board of directors of the Issuer, is a partner of Partners GP II and as a result, may be deemed to share voting and investment power with respect to the shares held by PIF II.
F4	The option shall vest in equal quarterly installments over the 12 months following the date of grant, provided that the grant will in any case be fully vested on the date of Issuer's 2026 annual meeting of stockholders, subject to the Reporting Person continuing to provide service through each such date.