Keros Therapeutics, Inc. — Director's Dealing 2021

Mar 6, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: Keros Therapeutics, Inc. (KROS)
CIK: 0001664710
Period of Report: 2021-03-03

Reporting Person: Knowles Julius (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-03-03	Common Stock	S	793	$55.91	Disposed	643695	Indirect
2021-03-03	Common Stock	S	518	$55.91	Disposed	429765	Indirect
2021-03-03	Common Stock	S	3004	$56.95	Disposed	640691	Indirect
2021-03-03	Common Stock	S	1958	$56.95	Disposed	427807	Indirect
2021-03-03	Common Stock	S	2903	$57.79	Disposed	637788	Indirect
2021-03-03	Common Stock	S	1894	$57.79	Disposed	425913	Indirect
2021-03-03	Common Stock	S	761	$58.88	Disposed	637027	Indirect
2021-03-03	Common Stock	S	496	$58.88	Disposed	425417	Indirect
2021-03-04	Common Stock	S	1662	$54.22	Disposed	635365	Indirect
2021-03-04	Common Stock	S	1086	$54.22	Disposed	424331	Indirect
2021-03-04	Common Stock	S	2962	$55.21	Disposed	632403	Indirect
2021-03-04	Common Stock	S	1932	$55.21	Disposed	422399	Indirect
2021-03-04	Common Stock	S	1376	$56.18	Disposed	631027	Indirect
2021-03-04	Common Stock	S	895	$56.18	Disposed	421504	Indirect
2021-03-04	Common Stock	S	847	$57.21	Disposed	630180	Indirect
2021-03-04	Common Stock	S	553	$57.21	Disposed	420951	Indirect
2021-03-04	Common Stock	S	193	$58.03	Disposed	629987	Indirect
2021-03-04	Common Stock	S	126	$58.03	Disposed	420825	Indirect

Footnotes

F1: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan.

F2: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $55.39 to
$56.32 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 sold at each separate price within the ranges set forth in
footnotes (2), (5), (6), (7), (8), (9), (10), (11) and (12).

F3: The securities are held by Partners Innovation Fund, LLC ("PIF I"). Partners Innovation Fund, LLC ("Partners GP I") is the ultimate general
partner of PIF I. The Reporting Person, a member of the board of directors of the Issuer, is a partner of Partners GP I and as a result, may be
deemed to share voting and investment power with respect to the shares held by PIF I.

F4: The securities are held by Partners Innovation Fund II, L.P. ("PIF II"). Partners Innovation Fund II, LLC ("Partners GP II") is the ultimate general
partner of PIF II. The Reporting Person, a member of the board of directors of the Issuer, is a partner of Partners GP II and as a result, may be
deemed to share voting and investment power with respect to the shares held by PIF II.

F5: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $56.41 to
$57.40 inclusive.

F6: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $57.42 to
$58.38 inclusive.

F7: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $58.46 to
$59.19 inclusive.

F8: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $53.76 to $54.72 inclusive.

F9: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $54.76 to $55.75 inclusive.

F10: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $55.77 to $56.75 inclusive.

F11: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $56.80 to $57.59 inclusive.

F12: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $57.86 to $58.18 inclusive.