Keros Therapeutics (KROS) awards Chief Legal Officer 80,000 options

Rhea-AI Filing Summary

Cho Esther reported acquisition or exercise transactions in this Form 4 filing.

Keros Therapeutics Chief Legal Officer Esther Cho reported an equity award of employee stock options. On February 24, 2026, she was granted 80,000 options to buy Keros Therapeutics common stock, all held as direct ownership, bringing her total derivative holdings to 80,000 options.

According to the vesting terms, one-fourth of the shares subject to the option will vest on February 24, 2027. The remaining shares will then vest in twelve substantially equal quarterly installments, as long as she continues to provide service through each vesting date.

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

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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^*

Cho Esther

(Last) (First) (Middle)

C/O KEROS THERAPEUTICS, INC.

1050 WALTHAM STREET, SUITE 302

(Street)

LEXINGTON MA 02421

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Keros Therapeutics, Inc. [ KROS ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
01/05/2026

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

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
Employee Stock Option (Right to Buy)	$15.52	02/24/2026		A		80,000		(1)	02/23/2036	Common Stock	80,000	$0	80,000	D

Explanation of Responses:

1. One-fourth (1/4th) of the shares subject to the option shall vest on February 24, 2027, and the remaining shares subject to the option shall vest in twelve substantially equal quarterly installments thereafter, subject to the Reporting Person continuing to provide service through each such date.

	/s/ Esther Cho	02/26/2026
	** 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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FAQ

What insider transaction did KROS Chief Legal Officer Esther Cho report?

Esther Cho reported receiving a grant of 80,000 employee stock options in Keros Therapeutics. The Form 4 shows these as derivative securities acquired on February 24, 2026, held as direct ownership, with 80,000 options reported as beneficially owned after the grant.

When do Esther Cho’s KROS stock options start vesting and over what schedule?

The options begin vesting on February 24, 2027. One-fourth of the shares subject to the option vest on that date, and the remaining shares vest in twelve substantially equal quarterly installments, contingent on her continuing to provide service through each scheduled vesting date.

How many Keros Therapeutics options does Esther Cho hold after this Form 4 transaction?

After the reported grant, Esther Cho holds 80,000 stock options in Keros Therapeutics. The Form 4 lists these as derivative securities beneficially owned following the transaction, all categorized under direct ownership, reflecting the full size of this award.

What type of security was granted to Esther Cho in this KROS Form 4 filing?

The filing reports an Employee Stock Option (Right to Buy) grant. This derivative security gives her the right to purchase Keros Therapeutics common stock, with vesting tied to continued service over a multi-year schedule described in the footnote.

Is Esther Cho’s 80,000-option award in KROS tied to her ongoing employment?

Yes, the vesting of the options depends on her continued service. The footnote explains that vesting occurs beginning February 24, 2027, with additional quarterly installments, provided she continues to provide service through each applicable vesting date.