Rhythm Pharmaceuticals, Inc. (RYTM) Institutional Ownership

Ownership Summary

Rhythm Pharmaceuticals, Inc. (NASDAQ:RYTM) is held by 283 institutional investors per 13F filings through March 2026.

• They owned 109.6% of outstanding stock in March 2026, down from 114.0% the prior quarter.
• Their total shares held in RYTM increased 17.88% quarter over quarter, and separately, investors owning Rhythm Pharmaceuticals increased 22.51% from a year ago.
• During the quarter, 168 of these 283 funds increased positions in RYTM, 85 reduced exposure, and 30 held steady.
• Combined, these investors held 74.48Mn shares in RYTM for March 2026, up by 11.3Mn shares quarter on quarter, and up 2.52Mn shares year over year.
• RA CAPITAL MANAGEMENT, L.P. holds the largest position in RYTM at 6.67Mn shares as of March 31, 2026, or 9.81% of shares outstanding.
• Leading buyers of Rhythm Pharmaceuticals shares for the quarter ending March 2026 were VANGUARD PORTFOLIO MANAGEMENT LLC (3.04Mn), VANGUARD CAPITAL MANAGEMENT LLC (2.97Mn), PRICE T ROWE ASSOCIATES INC /MD/ (1.65Mn), CITADEL ADVISORS LLC (1.27Mn), Janus Henderson Group Plc (710.18K).
• The biggest sellers of Rhythm Pharmaceuticals for the quarter ending March 2026 included Goldman Sachs Group Inc (1.7Mn), DRIEHAUS CAPITAL MANAGEMENT LLC (848.68K), Opaleye Management Inc. (537.0K), Rockefeller Capital Management L.P. (459.82K), Federated Hermes, Inc. (337.54K).
• Rhythm Pharmaceuticals's 10 largest shareholders as of March 2026 include RA CAPITAL MANAGEMENT, L.P. (6.67Mn), BlackRock, Inc. (6.24Mn), BAKER BROS. ADVISORS LP (5.6Mn), PRIMECAP MANAGEMENT CO/CA/ (3.42Mn), VANGUARD PORTFOLIO MANAGEMENT LLC (3.04Mn), VANGUARD CAPITAL MANAGEMENT LLC (2.97Mn), PERCEPTIVE ADVISORS LLC (2.37Mn), State Street Corp (2.27Mn), Goldman Sachs Group Inc (1.97Mn), WESTFIELD CAPITAL MANAGEMENT CO LP (1.93Mn) per Business Quant data.