ADAR1 Capital Management, LLC - 08 Apr 2025 Form 3 Insider Report for Keros Therapeutics, Inc. (KROS)

Role: 10%+ Owner
Signature: ADAR1 Capital Management, LLC, By /s/ Daniel Schneeberger, Manager
Issuer symbol: KROS
Transactions as of: 08 Apr 2025
Net transactions value: $0
Form type: 3
Filing time: 11 Apr 2025, 20:58:32 UTC
Previous filing: 12 Aug 2024
Next filing: 11 Apr 2025
SEC: View on sec.gov

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
holding	KROS	Common Stock						3,474,844	08 Apr 2025	By ADAR1 Partners, LP	F1, F11
holding	KROS	Common Stock						254,669	08 Apr 2025	By ADAR1 SPV I, LP	F2, F11
holding	KROS	Common Stock						727,193	08 Apr 2025	By Spearhead Insurance Solutions IDF, LLC	F3, F11

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
holding	KROS	Put Option (obligation to buy)							08 Apr 2025	Common Stock	30,000	$10.00	By ADAR1 Partners, LP	F4, F11
holding	KROS	Put Option (obligation to buy)							08 Apr 2025	Common Stock	83,600	$10.00	By ADAR1 Partners, LP	F5, F11
holding	KROS	Put Option (obligation to buy)							08 Apr 2025	Common Stock	17,800	$10.00	By Spearhead Insurance Solutions IDF, LLC	F6, F11
holding	KROS	Put Option (right to sell)							08 Apr 2025	Common Stock	1,400	$70.00	By ADAR1 Partners, LP	F7, F11
holding	KROS	Put Option (right to sell)							08 Apr 2025	Common Stock	100	$60.00	By ADAR1 Partners, LP	F8, F11
holding	KROS	Put Option (right to sell)							08 Apr 2025	Common Stock	200	$70.00	By Spearhead Insurance Solutions IDF, LLC	F9, F11
holding	KROS	Cash-Settled Total Return Swaps							08 Apr 2025	Common Stock	949,333		By ADAR1 Partners, LP	F10, F11

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

Explanation of Responses:

Id	Content
F1	ADAR1 Partners, LP is a direct beneficial owner 3,474,844 shares of Common Stock of the Issuer. As the investment manager of ADAR1 Partners, LP, ADAR1 Capital Management, LLC may be deemed to be an indirect beneficial owner of such shares. As the general partner of ADAR1 Partners, LP, ADAR1 Capital Management GP, LLC may be deemed to be the indirect beneficial owner of such shares. As the manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC, Daniel Schneeberger may be deemed to be the indirect beneficial owner of such shares.
F2	ADAR1 SPV I, LP is a direct beneficial owner 254,669 shares of Common Stock of the Issuer. As the investment manager of ADAR1 SPV I, LP, ADAR1 Capital Management, LLC may be deemed to be an indirect beneficial owner of such shares. As the general partner of ADAR1 SPV I, LP, ADAR1 Capital Management GP, LLC may be deemed to be the indirect beneficial owner of such shares. As the manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC, Daniel Schneeberger may be deemed to be the indirect beneficial owner of such shares.
F3	Spearhead Insurance Solutions IDF, LLC is a direct beneficial owner 727,193 shares of Common Stock of the Issuer. As the sub-advisor of Spearhead Insurance Solutions IDF, LLC, ADAR1 Capital Management, LLC may be deemed to be an indirect beneficial owner of such shares. As the manager of ADAR1 Capital Management, LLC, Daniel Schneeberger may be deemed to be the indirect beneficial owner of such shares.
F4	ADAR1 Partners, LP is party to put option contracts that provide for an obligation to buy 30,000 shares of Common Stock of the Issuer, if such put options are exercised by the counterparties to such put options. As the investment manager of ADAR1 Partners, LP, ADAR1 Capital Management, LLC may be deemed to be an indirect beneficial owner of such put options. As the general partner of ADAR1 Partners, LP, ADAR1 Capital Management GP, LLC may be deemed to be the indirect beneficial owner of such put options. As the manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC, Daniel Schneeberger may be deemed to be the indirect beneficial owner of such put options.
F5	ADAR1 Partners, LP is party to put option contracts that provide for an obligation to buy 83,600 shares of Common Stock of the Issuer, if such put options are exercised by the counterparties to such put options. As the investment manager of ADAR1 Partners, LP, ADAR1 Capital Management, LLC may be deemed to be an indirect beneficial owner of such put options. As the general partner of ADAR1 Partners, LP, ADAR1 Capital Management GP, LLC may be deemed to be the indirect beneficial owner of such put options. As the manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC, Daniel Schneeberger may be deemed to be the indirect beneficial owner of such put options.
F6	Spearhead Insurance Solutions IDF, LLC is party to put option contracts that provide for an obligation to buy 17,800 shares of Common Stock of the Issuer, if such put options are exercised by the counterparties to such put options. As the sub-advisor of Spearhead Insurance Solutions IDF, LLC, ADAR1 Capital Management, LLC may be deemed to be an indirect beneficial owner of such put options. As the manager of ADAR1 Capital Management, LLC, Daniel Schneeberger may be deemed to be the indirect beneficial owner of such put options.
F7	ADAR1 Partners, LP is a direct beneficial owner of fourteen put options, each with a right to sell 100 shares of Common Stock of the Issuer, exercisable by ADAR1 Partners, LP in its discretion. As the investment manager of ADAR1 Partners, LP, ADAR1 Capital Management, LLC may be deemed to be an indirect beneficial owner of such put options. As the general partner of ADAR1 Partners, LP, ADAR1 Capital Management GP, LLC may be deemed to be the indirect beneficial owner of such put options. As the manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC, Daniel Schneeberger may be deemed to be the indirect beneficial owner of such put options.
F8	ADAR1 Partners, LP is a direct beneficial owner of one put option, with a right to sell 100 shares of Common Stock of the Issuer, exercisable by ADAR1 Partners, LP in its discretion. As the investment manager of ADAR1 Partners, LP, ADAR1 Capital Management, LLC may be deemed to be an indirect beneficial owner of such put option. As the general partner of ADAR1 Partners, LP, ADAR1 Capital Management GP, LLC may be deemed to be the indirect beneficial owner of such put option. As the manager of ADAR1 Capital Management, LLC and ADAR1 Capital Management GP, LLC, Daniel Schneeberger may be deemed to be the indirect beneficial owner of such put option.
F9	Spearhead Insurance Solutions IDF, LLC is a direct beneficial owner of two put options, each with a right to sell 100 shares of Common Stock of the Issuer, exercisable by Spearhead Insurance Solutions IDF, LLC in its discretion. As the sub-advisor of Spearhead Insurance Solutions IDF, LLC, ADAR1 Capital Management, LLC may be deemed to be an indirect beneficial owner of such put options. As the manager of ADAR1 Capital Management, LLC, Daniel Schneeberger may be deemed to be the indirect beneficial owner of such put option.
F10	ADAR1 Partners, LP previously entered into certain cash-settled total return swap agreements with an unaffiliated third-party financial institution, which as of the close of business on April 8, 2025, provide ADAR1 Partners, LP with economic exposure to an aggregate of 949,333 notional shares of Common Stock of the Issuer. The swap agreements provide the ADAR1 Partners, LP with economic results that are comparable to the economic results of ownership but do not provide ADAR1 Partners, LP with the power to vote or direct the voting or dispose of or direct the disposition of the shares of common stock that are the subject of the swap agreements (the "Subject Shares"). Each of the Reporting Persons disclaims beneficial ownership of the Subject Shares except to the extent of its or his pecuniary interest therein.
F11	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.