ADAR1 Capital Management, LLC - May 16, 2025 Form 4 Insider Report for Keros Therapeutics, Inc. (KROS)

Role: 10%+ Owner
Signature: ADAR1 Capital Management, LLC, By: Daniel Schneeberger, Manager /s/ Daniel Schneeberger
Stock symbol: KROS
Transactions as of: May 16, 2025
Transactions value $: $0
Form type: 4
Date filed: 6/12/2025, 04:51 PM
Previous filing: Apr 11, 2025
Next filing: Jun 24, 2025
SEC: View on sec.gov

Reporting Owners (4)

Name	Relationship	Address	Signature	Signature date	CIK
ADAR1 Capital Management, LLC	10%+ Owner	3503 WILD CHERRY DRIVE, BUILDING 9, AUSTIN	ADAR1 Capital Management, LLC, By: Daniel Schneeberger, Manager /s/ Daniel Schneeberger	2025-06-12	0001940272
ADAR1 Partners, LP	10%+ Owner	3503 WILD CHERRY DRIVE, BUILDING 9, AUSTIN	ADAR1 Partners, LP, By: Daniel Schneeberger, Manager /s/ Daniel Schneeberger	2025-06-12	0001758866
ADAR1 Capital Management GP, LLC	10%+ Owner	3503 WILD CHERRY DRIVE, BUILDING 9, AUSTIN	ADAR1 Capital Management GP, LLC, By: Daniel Schneeberger, Manager /s/ Daniel Schneeberger	2025-06-12	0001940267
Schneeberger Daniel	10%+ Owner	3503 WILD CHERRY DRIVE, BUILDING 9, AUSTIN	/s/ Daniel Schneeberger	2025-06-12	0001861120

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

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	KROS	Put Option (obligation to buy)	Expiration of short derivative position	$0	-300	-100%	$0.00	May 16, 2025	Common Stock	30K	$10.00	By ADAR1 Partners, LP	F1, F2
transaction	KROS	Put Option (obligation to buy)	Expiration of short derivative position	$0	-836	-100%	$0.00	May 16, 2025	Common Stock	83.6K	$10.00	By ADAR1 Partners, LP	F1, F2
transaction	KROS	Put Option (obligation to buy)	Expiration of short derivative position	$0	-178	-100%	$0.00	May 16, 2025	Common Stock	17.8K	$10.00	By Spearhead Insurance Solutions IDF, LLC	F1, F2

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

Explanation of Responses:

Id	Content
F1	As the investment manager of ADAR1 Partners, LP and as the sub-advisor of Spearhead Insurance Solutions IDF, LLC, ADAR1 Capital Management, LLC may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP and Spearhead Insurance Solutions IDF, LLC. As the general partner of ADAR1 Partners, LP, ADAR1 Capital Management GP, LLC may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP. As the manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC, Mr. Schneeberger may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP and Spearhead Insurance Solutions IDF, LLC.
F2	For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.

Content

As the investment manager of ADAR1 Partners, LP and as the sub-advisor of Spearhead Insurance Solutions IDF, LLC, ADAR1 Capital Management, LLC may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP and Spearhead Insurance Solutions IDF, LLC. As the general partner of ADAR1 Partners, LP, ADAR1 Capital Management GP, LLC may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP. As the manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC, Mr. Schneeberger may be deemed to indirectly beneficially own securities held by ADAR1 Partners, LP and Spearhead Insurance Solutions IDF, LLC.

For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, each Reporting Person disclaims beneficial ownership of any such securities, except to the extent of his/its pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of such securities for purposes of Section 16 or otherwise.