{"data":[{"accessionNo":"0000019617-26-000351","formType":"SCHEDULE 13G","amendmentNo":null,"issuerCik":"0001649904","issuerName":"RHYTHM PHARMACEUTICALS, INC.","ticker":"RYTM","cusip":"76243J105","securityClass":"Common Stock, $0.001 par value per share","eventDate":"2026-09-30","reportingPerson":"JPMORGAN CHASE & CO.","reportingCik":null,"personType":"HC","sharesOwned":3563667,"percentOfClass":5.1,"filedAt":"2026-10-13","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0001193125-26-226562","formType":"SCHEDULE 13G/A","amendmentNo":2,"issuerCik":"0001649904","issuerName":"RHYTHM PHARMACEUTICALS, INC.","ticker":"RYTM","cusip":"76243J105","securityClass":"Common Stock, $0.001 par value per share","eventDate":"2026-03-31","reportingPerson":"Perceptive Advisors LLC","reportingCik":null,"personType":"IA","sharesOwned":3519626,"percentOfClass":5.1,"filedAt":"2026-05-15","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0001193125-26-226562","formType":"SCHEDULE 13G/A","amendmentNo":2,"issuerCik":"0001649904","issuerName":"RHYTHM PHARMACEUTICALS, INC.","ticker":"RYTM","cusip":"76243J105","securityClass":"Common Stock, $0.001 par value per share","eventDate":"2026-03-31","reportingPerson":"Joseph Edelman","reportingCik":null,"personType":"IN","sharesOwned":3519626,"percentOfClass":5.1,"filedAt":"2026-05-15","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0001193125-26-226562","formType":"SCHEDULE 13G/A","amendmentNo":2,"issuerCik":"0001649904","issuerName":"RHYTHM PHARMACEUTICALS, INC.","ticker":"RYTM","cusip":"76243J105","securityClass":"Common Stock, $0.001 par value per share","eventDate":"2026-03-31","reportingPerson":"Perceptive Life Sciences Master Fund, Ltd.","reportingCik":null,"personType":"CO","sharesOwned":2790461,"percentOfClass":4.1,"filedAt":"2026-05-15","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0001193125-26-226562","formType":"SCHEDULE 13G/A","amendmentNo":2,"issuerCik":"0001649904","issuerName":"RHYTHM PHARMACEUTICALS, INC.","ticker":"RYTM","cusip":"76243J105","securityClass":"Common Stock, $0.001 par value per share","eventDate":"2026-03-31","reportingPerson":"Perceptive Capital Solutions Holdings LP","reportingCik":null,"personType":"PN","sharesOwned":729165,"percentOfClass":1.1,"filedAt":"2026-05-15","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0002100119-26-000980","formType":"SCHEDULE 13G","amendmentNo":null,"issuerCik":"0001649904","issuerName":"Rhythm Pharmaceuticals Inc","ticker":"RYTM","cusip":"76243J105","securityClass":"Common Stock","eventDate":"2026-03-31","reportingPerson":"Vanguard Capital Management","reportingCik":null,"personType":"IA","sharesOwned":3432949,"percentOfClass":5.02,"filedAt":"2026-04-30","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0000102909-26-002111","formType":"SCHEDULE 13G/A","amendmentNo":3,"issuerCik":"0001649904","issuerName":"Rhythm Pharmaceuticals Inc","ticker":"RYTM","cusip":"76243J105","securityClass":"Common Stock","eventDate":"2026-03-13","reportingPerson":"The Vanguard Group","reportingCik":null,"personType":"IA","sharesOwned":0,"percentOfClass":0,"filedAt":"2026-03-27","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0001346824-26-000055","formType":"SCHEDULE 13G/A","amendmentNo":8,"issuerCik":"0001649904","issuerName":"RHYTHM PHARMACEUTICALS, INC.","ticker":"RYTM","cusip":null,"securityClass":"Common Stock, $0.001 par value per share","eventDate":"2025-12-31","reportingPerson":"RA Capital Management, L.P.","reportingCik":null,"personType":"IA,PN","sharesOwned":6666837,"percentOfClass":9.9,"filedAt":"2026-02-17","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0001346824-26-000055","formType":"SCHEDULE 13G/A","amendmentNo":8,"issuerCik":"0001649904","issuerName":"RHYTHM PHARMACEUTICALS, INC.","ticker":"RYTM","cusip":null,"securityClass":"Common Stock, $0.001 par value per share","eventDate":"2025-12-31","reportingPerson":"Peter Kolchinsky","reportingCik":null,"personType":"HC,IN","sharesOwned":6666837,"percentOfClass":9.9,"filedAt":"2026-02-17","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0001346824-26-000055","formType":"SCHEDULE 13G/A","amendmentNo":8,"issuerCik":"0001649904","issuerName":"RHYTHM PHARMACEUTICALS, INC.","ticker":"RYTM","cusip":null,"securityClass":"Common Stock, $0.001 par value per share","eventDate":"2025-12-31","reportingPerson":"Rajeev Shah","reportingCik":null,"personType":"HC,IN","sharesOwned":6666837,"percentOfClass":9.9,"filedAt":"2026-02-17","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0001346824-26-000055","formType":"SCHEDULE 13G/A","amendmentNo":8,"issuerCik":"0001649904","issuerName":"RHYTHM PHARMACEUTICALS, INC.","ticker":"RYTM","cusip":null,"securityClass":"Common Stock, $0.001 par value per share","eventDate":"2025-12-31","reportingPerson":"RA Capital Healthcare Fund, L.P.","reportingCik":null,"personType":"PN","sharesOwned":6666837,"percentOfClass":9.9,"filedAt":"2026-02-17","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0000763212-26-000014","formType":"SCHEDULE 13G/A","amendmentNo":12,"issuerCik":"0001649904","issuerName":"RHYTHM PHARMACEUTICALS, INC.","ticker":"RYTM","cusip":null,"securityClass":"COM","eventDate":"2025-12-31","reportingPerson":"PRIMECAP MANAGEMENT CO/CA/","reportingCik":null,"personType":"IA","sharesOwned":3478669,"percentOfClass":5.21,"filedAt":"2026-02-12","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0000102909-26-000254","formType":"SCHEDULE 13G/A","amendmentNo":2,"issuerCik":"0001649904","issuerName":"Rhythm Pharmaceuticals Inc","ticker":"RYTM","cusip":null,"securityClass":"Common Stock","eventDate":"2025-12-31","reportingPerson":"The Vanguard Group","reportingCik":null,"personType":"IA","sharesOwned":6210916,"percentOfClass":9.3,"filedAt":"2026-01-30","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0001085146-25-005989","formType":"SCHEDULE 13G/A","amendmentNo":11,"issuerCik":"0001649904","issuerName":"Rhythm Pharmaceuticals, Inc.","ticker":"RYTM","cusip":null,"securityClass":"COM","eventDate":"2025-09-30","reportingPerson":"PRIMECAP MANAGEMENT CO/CA/","reportingCik":null,"personType":"IA","sharesOwned":4262859,"percentOfClass":6.42,"filedAt":"2025-11-14","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"},{"accessionNo":"0000102909-25-000210","formType":"SCHEDULE 13G/A","amendmentNo":1,"issuerCik":"0001649904","issuerName":"Rhythm Pharmaceuticals Inc","ticker":"RYTM","cusip":null,"securityClass":"Common Stock","eventDate":"2025-09-30","reportingPerson":"The Vanguard Group","reportingCik":null,"personType":"IA","sharesOwned":4996427,"percentOfClass":7.52,"filedAt":"2025-10-30","canonicalUrl":"https://xoomar.com/markets/stocks/rytm"}],"updatedAt":"2026-11-04T07:58:52.960Z","source":"xoomar.com","docs":"https://xoomar.com/markets/api","license":"https://xoomar.com/terms","attribution":"Credit XOOMAR with a link to the dataset page on xoomar.com when you republish this data","canonicalUrl":"https://xoomar.com/markets/stocks/rytm","meta":{"source":"SEC","sourceAttribution":"Schedule 13D and 13G data: SEC.","notice":"10 requests a minute without a key, 30 with a free key. Get a free key at https://xoomar.com/signup?utm_source=api, register your app at https://xoomar.com/developers/register?utm_source=api, and credit the data as \"Data: XOOMAR\" together with the sourceAttribution line."}}