Who owns RYTM?
Institutional ownership of Rhythm Pharmaceuticals Inc. from Form 13F, Q2 2026
303 institutional managers reported holding Rhythm Pharmaceuticals Inc. (RYTM) in Form 13F filings for Q2 2026, with 77,413,117 shares worth $8.6B. The largest reported holder was Ra Capital Management, L.p. Managers that filed both quarters added a net 3,834,313 shares (+5.3%). 59 opened new positions and 41 sold out.
- Funds holding
- 303
- Value held
- $8.6B
- New / sold out
- 59 / 41
- Net shares, same filers
- +5.3%
Holdings as of June 30, 2026, the end of Q2 2026. Managers have 45 days after a quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.
Largest holders of RYTM
| Fund | Value | Share of 13F holdings | Shares | Move |
|---|---|---|---|---|
| Ra Capital Management, L.p. | $740M | 8.6% | 6,666,837 | Unchanged |
| BlackRock, Inc. | $684M | 8.0% | 6,156,902 | Trimmed |
| Baker Bros. Advisors LP | $622M | 7.2% | 5,604,483 | Unchanged |
| Primecap Management Co | $352M | 4.1% | 3,168,853 | Trimmed |
| Vanguard Portfolio Management LLC | $348M | 4.1% | 3,136,895 | Added |
| Vanguard Capital Management LLC | $334M | 3.9% | 3,005,977 | Added |
| JPMorgan Chase & Co | $292M | 3.4% | 2,652,746 | Added |
| Perceptive Advisors LLC | $287M | 3.3% | 2,586,295 | Added |
| State Street Corp | $286M | 3.3% | 2,573,529 | Added |
| Price T Rowe Associates Inc | $285M | 3.3% | 2,566,171 | Added |
| Westfield Capital Management Co LP | $245M | 2.9% | 2,208,595 | Added |
| Goldman Sachs Group Inc | $236M | 2.7% | 2,126,502 | Added |
| Federated Hermes, Inc. | $198M | 2.3% | 1,785,716 | Added |
| Polar Capital Holdings Plc | $185M | 2.1% | 1,663,632 | Added |
| Geode Capital Management, LLC | $170M | 2.0% | 1,533,698 | Added |
| Capital Research Global Investors | $170M | 2.0% | 1,532,303 | Added |
| Citadel Advisors LLC | $140M | 1.6% | 1,263,652 | Trimmed |
| Checkpoint Capital L.P. | $132M | 1.5% | 1,186,000 | Trimmed |
| Siren, L.L.C. | $126M | 1.5% | 1,136,275 | Added |
| Morgan Stanley | $123M | 1.4% | 1,112,240 | Added |
| FMR LLC | $114M | 1.3% | 1,025,840 | Trimmed |
| Pictet Asset Management Holding SA | $106M | 1.2% | 957,785 | Added |
| Jupiter Topco LLC | $103M | 1.2% | 925,490 | First report |
| Woodline Partners LP | $84.3M | 1.0% | 758,891 | Unchanged |
| Alliancebernstein L.p. | $77.8M | 1.2% | 894,723 | Trimmed |
Share of 13F holdings is each fund's shares as a share of the 77,413,117 RYTM shares all 13F filers reported, not of shares outstanding.
Biggest buyers in Q2 2026
- JPMorgan Chase & Co Added+$121M
- Price T Rowe Associates Inc Added+$101M
- Norges Bank New+$76.1M
- Federated Hermes, Inc. Added+$55.4M
- Capital Research Global Investors Added+$46.3M
- Siren, L.L.C. Added+$45.6M
- Morgan Stanley Added+$45.3M
- Assenagon Asset Management S.A. New+$41.4M
- State Street Corp Added+$33.5M
- Pictet Asset Management Holding SA Added+$32.3M
Biggest sellers in Q2 2026
- FMR LLC Trimmed-$73.7M
- Point72 Asset Management, L.P. Trimmed-$48.0M
- Adage Capital Partners GP, L.l.c. Trimmed-$36.5M
- Logos Global Management LP Trimmed-$36.1M
- Driehaus Capital Management LLC Trimmed-$34.1M
- Bank of America Corp Trimmed-$33.7M
- Lord, Abbett & Co. LLC Sold out-$30.3M
- Primecap Management Co Trimmed-$27.6M
- Renaissance Technologies LLC Trimmed-$21.1M
- Hood River Capital Management LLC Sold out-$20.9M
The change in shares since the quarter before, adjusted for stock splits and priced at the Q2 2026 value per share. Funds bought $1.0B and sold $589M; 105 added and 99 trimmed.
Schedule 13D and 13G filings on RYTM
Owners of more than 5% must file within days, so these can be newer than the 13F data.
- 2026-10-13JPMORGAN CHASE & CO SCHEDULE 13G filed by Rhythm Pharmaceuticals Inc.Schedule 13G
Questions about RYTM ownership
- Who owns RYTM stock?
- 303 institutional investment managers reported RYTM positions in their Form 13F filings for Q2 2026, holding 77,413,117 shares worth $8.6B in total. Ra Capital Management, L.p. reported the largest position.
- Are funds buying or selling RYTM?
- In Q2 2026, 59 managers opened new RYTM positions, 105 added, 99 trimmed and 41 sold out. Managers that filed in both quarters added a net 3,834,313 shares.
- How current is this RYTM institutional ownership data?
- It covers holdings as of the end of Q2 2026. Managers have 45 days after the quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.
From the SEC's Form 13F data sets for Q2 2026: every 13F holdings report, matched to RYTM by CUSIP. Options are left out. RYTM news and filings · RYTM insider trades · Top funds