{"transactions":[{"id":679613,"issuer":{"id":6242,"kind":"organization","name":"Keros Therapeutics, Inc."},"owners":[{"id":21144,"kind":"person","name":"Cho Esther","position":1,"cik":"0002081460","reported_name":"Cho Esther","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Common Stock","published_at":"2026-08-20T20:10:08.000Z","date":"2026-08-18","kind":"sale","planned":false,"acquired":false,"shares":4485,"price":10.29,"value":46150.65,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"The Issuer has adopted a \"sell-to-cover\" policy to satisfy the tax withholding obligations of the Reporting Person. The sales reported on this Form 4 represent the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units. Such sales were automatic and not at the discretion of the Reporting Person."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $10.14 to $10.50 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 range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes an aggregate of 500 shares acquired under the Issuer's 2020 Employee Stock Purchase Plan."}],"balance_after":35770,"source":{"system":"sec-edgar","filing":"0002081460-26-000009","document":"form4-08202026_040803.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1664710/000208146026000009/form4-08202026_040803.xml","form_type":"4"}},{"id":826072,"issuer":{"id":6242,"kind":"organization","name":"Keros Therapeutics, Inc."},"owners":[{"id":21144,"kind":"person","name":"Cho Esther","position":1,"cik":"0002081460","reported_name":"Cho Esther","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Employee Stock Option (Right to Buy)","published_at":"2026-03-27T20:15:14.000Z","date":"2026-02-24","kind":"grant","planned":false,"acquired":true,"shares":80000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"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."}],"balance_after":80000,"derivative":{"exercise_price":15.52,"expiration_date":"2036-02-23","underlying":"Common Stock","underlying_shares":80000},"source":{"system":"sec-edgar","filing":"0002081460-26-000007","document":"form4a-03272026_040301.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1664710/000208146026000007/form4a-03272026_040301.xml","form_type":"4/A","original_submission_date":"2026-02-26"}},{"id":879238,"issuer":{"id":6242,"kind":"organization","name":"Keros Therapeutics, Inc."},"owners":[{"id":21144,"kind":"person","name":"Cho Esther","position":1,"cik":"0002081460","reported_name":"Cho Esther","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Legal Officer"}}],"security":"Employee Stock Option (Right to Buy)","published_at":"2026-02-26T21:15:20.000Z","date":"2026-02-24","kind":"grant","planned":false,"acquired":true,"shares":80000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"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."}],"balance_after":80000,"derivative":{"exercise_price":15.52,"expiration_date":"2036-02-23","underlying":"Common Stock","underlying_shares":80000},"source":{"system":"sec-edgar","filing":"0002081460-26-000004","document":"form4-02262026_040212.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1664710/000208146026000004/form4-02262026_040212.xml","form_type":"4"}},{"id":890169,"issuer":{"id":6242,"kind":"organization","name":"Keros Therapeutics, Inc."},"owners":[{"id":21144,"kind":"person","name":"Cho Esther","position":1,"cik":"0002081460","reported_name":"Cho Esther","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"SVP, General Counsel"}}],"security":"Common Stock","published_at":"2026-02-20T21:15:11.000Z","date":"2026-02-18","kind":"sale","planned":false,"acquired":false,"shares":4745,"price":16.35,"value":77580.75,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"The Issuer has adopted a \"sell-to-cover\" policy to satisfy the tax withholding obligations of the Reporting Person. The sales reported on this Form 4 represent the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units. Such sales were automatic and not at the discretion of the Reporting Person."},{"field":"price","element":"transactionPricePerShare","label":"F2","text":"The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.05 to $16.65 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 range set forth in this footnote."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Includes an aggregate of 500 shares acquired under the Issuer's 2020 Employee Stock Purchase Plan."}],"balance_after":39755,"source":{"system":"sec-edgar","filing":"0002081460-26-000002","document":"form4-02202026_040204.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1664710/000208146026000002/form4-02202026_040204.xml","form_type":"4"}}]}