Keros Therapeutics director plans sale of 551 shares

Rhea-AI Filing Summary

Keros Therapeutics, Inc. (KROS) director Charles W. Newton has filed a notice under Rule 144 for a planned sale of common stock through UBS Financial Services Inc. The filing lists a proposed sale of 551 shares of Keros common stock, related to restricted stock units (RSUs) from the issuer with an indicated date of August 15, 2026. The filing also notes a prior sale in the last three months of 550 shares of Keros common stock on June 11, 2026.

Key Figures

Planned shares to be sold: 551 shares Security type: Common stock Related equity award type: RSU +1 more

4 metrics

Planned shares to be sold 551 shares Proposed sale of Keros Therapeutics, Inc. common stock under Rule 144

Security type Common stock Keros Therapeutics, Inc. shares subject to the Form 144 notice

Related equity award type RSU Shares to be sold are tied to restricted stock units from the issuer

Prior shares sold 550 shares Common shares sold by Charles W. Newton on June 11, 2026

Key Terms

Rule 144, restricted stock units (RSUs), attorney-in-fact

3 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

restricted stock units (RSUs) financial

"Common | 08/15/2026 | RSU | Issuer"

Restricted stock units (RSUs) are a type of company promise to give employees shares of stock in the future, usually after certain conditions like working for a set time. They are like a gift promised today that you receive later, which can become valuable if the company's stock price goes up. RSUs matter because they are a way companies reward employees and can be a significant part of compensation.

attorney-in-fact regulatory

"UBS Financial Services Inc, as attorney-in-fact for Charles Newton"

An attorney-in-fact is the person or entity given legal authority through a power of attorney to act on behalf of another for specific tasks, such as signing documents, voting shares, or handling transactions. For investors, this matters because it lets a trusted representative make timely decisions or complete paperwork when the owner cannot, much like handing keys to someone to run errands on your behalf—so checks on scope and limits of that authority are important.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does the Form 144 filing mean for Keros Therapeutics, Inc. (KROS)?

The Form 144 filing indicates that a Keros Therapeutics, Inc. director plans to sell shares of common stock under Rule 144. It is a required advance notice for certain insider sales and does not by itself change the company’s operations or financial condition.

How many KROS shares is Charles W. Newton planning to sell under this Form 144?

Charles W. Newton plans to sell 551 shares of Keros Therapeutics, Inc. common stock. These shares are tied to restricted stock units (RSUs) from the issuer, with an indicated date of August 15, 2026.

What prior KROS share sales are disclosed in this Form 144?

The filing discloses that Charles W. Newton sold 550 shares of Keros Therapeutics, Inc. common stock on June 11, 2026. Rule 144 requires disclosure of certain sales made in the three months preceding the notice.

Who is conducting the planned KROS share sale for Charles W. Newton?

The planned sale of Keros Therapeutics, Inc. common stock will be handled by UBS Financial Services Inc.. UBS is listed as the broker through which the 551-share Rule 144 sale is expected to occur.

What is the role of RSUs in this KROS Form 144 filing?

The Form 144 notes that the planned sale of 551 shares of Keros Therapeutics, Inc. common stock is related to restricted stock units (RSUs) from the issuer, with an indicated RSU-related date of August 15, 2026.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/18/2026 - 04:12 PM Accepted by SEC EDGAR 08/18/2026 - 04:11 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001866219
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Keros Therapeutics, Inc.
SEC File Number	001-39264
Address of Issuer	1050 WALTHAM STREET, SUITE 302 LEXINGTON MASSACHUSETTS 02421
Phone	617-314-6297
Name of Person for Whose Account the Securities are To Be Sold	Newton Charles W.
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Director

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	UBS Financial Services, Inc. 11 Madison Ave 4th Floor New York NY 10010	551	5719.38	19827188	08/18/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	08/15/2026	RSU	Issuer			551	08/15/2026	N/A

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Charles W Newton 1050 WALTHAM STREET SUITE 302 Lexington MA 02421	Common	06/11/2026	550	5519.64

144: Remarks and Signature

Remarks
Date of Notice	08/18/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	03/12/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ UBS Financial Services Inc, as attorney-in-fact for Charles Newton
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)