Director adds Keros Therapeutics (NASDAQ: KROS) shares under 10b5-1 plan

Rhea-AI Filing Summary

Keros Therapeutics director Jean Jacques Bienaime bought 2,000 shares of common stock in an open-market transaction. The purchase took place on March 9, 2026 at a weighted average price of $11.21 per share, with individual trade prices ranging from $10.98 to $11.48. Following this transaction, Bienaime directly owns 7,450 Keros shares. The filing notes that the trade was executed under a pre-arranged Rule 10b5-1 trading plan adopted on December 5, 2025, indicating the purchase was scheduled in advance rather than timed discretionarily.

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

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

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^*

BIENAIME JEAN JACQUES

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
03/09/2026

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
Common Stock	03/09/2026		P(1)		2,000	A	$11.21(2)	7,450	D

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

Explanation of Responses:

1. Shares were purchased pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 5, 2025.

2. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $10.98 to $11.48 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

	/s/ Esther Cho, Attorney-in-Fact	03/11/2026
	** 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.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Keros Therapeutics (KROS) director Jean Jacques Bienaime do in this Form 4 filing?

Jean Jacques Bienaime reported buying 2,000 shares of Keros Therapeutics common stock. The open-market purchase occurred on March 9, 2026 at a weighted average price of $11.21 per share, increasing his direct holdings to 7,450 shares.

At what price did KROS director Jean Jacques Bienaime buy Keros Therapeutics shares?

The reported weighted average purchase price was $11.21 per share. Footnotes state the 2,000 shares were bought in multiple transactions, with trade prices ranging from $10.98 to $11.48 inclusive during the March 9, 2026 buying activity.

How many Keros Therapeutics (KROS) shares does Jean Jacques Bienaime own after this transaction?

After the March 9, 2026 purchase, Jean Jacques Bienaime directly owns 7,450 Keros Therapeutics common shares. This reflects the addition of 2,000 shares bought in the open market, as disclosed in the Form 4 insider trading report.

Was the Keros Therapeutics (KROS) share purchase by Jean Jacques Bienaime under a Rule 10b5-1 plan?

Yes. The filing states the 2,000-share purchase was made under a Rule 10b5-1 trading plan. This plan was adopted by Jean Jacques Bienaime on December 5, 2025, meaning the transaction was pre-scheduled rather than opportunistic.

What type of transaction is reported for Keros Therapeutics (KROS) director Jean Jacques Bienaime?

The Form 4 reports an open-market purchase of common stock. It is coded as a “P” transaction, described as a purchase in an open market or private transaction, involving 2,000 shares bought on March 9, 2026.