Ranked by reported Q2 2026 13F market value
Share of total reported institutional value in RYTM held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | RA CAPITAL MANAGEMENT, L.P. | 6.7M | $740.2M | 0.0% | 9.719% | 6.43% |
| 2 | BlackRock, Inc. | 6.2M | $683.6M | -1.3% | 8.976% | 0.01% |
| 3 | BAKER BROS. ADVISORS LP | 5.6M | $622.3M | 0.0% | 8.171% | 3.12% |
| 4 | PRIMECAP MANAGEMENT CO/CA/ | 3.2M | $351.8M | -7.3% | 4.620% | 0.21% |
| 5 | VANGUARD PORTFOLIO MANAGEMENT LLC | 3.1M | $348.3M | +3.2% | 4.573% | 0.02% |
| 6 | VANGUARD CAPITAL MANAGEMENT LLC | 3.0M | $333.8M | +1.3% | 4.382% | 0.01% |
| 7 | JPMORGAN CHASE & CO | 2.7M | $292.2M | +70.7% | 3.867% | 0.02% |
| 8 | PERCEPTIVE ADVISORS LLC | 2.6M | $287.2M | +8.9% | 3.771% | 4.31% |
| 9 | STATE STREET CORP | 2.6M | $285.7M | +13.3% | 3.752% | 0.00% |
| 10 | WESTFIELD CAPITAL MANAGEMENT CO LP | 2.2M | $245.2M | +14.5% | 3.220% | 0.80% |
| 11 | GOLDMAN SACHS GROUP INC | 2.1M | $236.1M | +8.2% | 3.100% | 0.02% |
| 12 | FEDERATED HERMES, INC. | 1.8M | $198.3M | +38.8% | 2.603% | 0.29% |
| 13 | Polar Capital Holdings Plc | 1.7M | $184.7M | +3.0% | 2.425% | 0.44% |
| 14 | GEODE CAPITAL MANAGEMENT, LLC | 1.5M | $170.3M | +8.3% | 2.236% | 0.01% |
| 15 | Capital Research Global Investors | 1.5M | $170.1M | +37.4% | 2.234% | 0.02% |
| 16 | CITADEL ADVISORS LLC | 1.3M | $145.4M | -9.9% | 1.909% | 0.01% |
| 17 | Checkpoint Capital L.P. | 1.2M | $131.7M | -3.4% | 1.729% | 33.79% |
| 18 | Siren, L.L.C. | 1.1M | $126.2M | +56.6% | 1.657% | 2.55% |
| 19 | MORGAN STANLEY | 1.1M | $123.5M | +58.0% | 1.621% | 0.01% |
| 20 | FMR LLC | 1.0M | $113.9M | -39.3% | 1.496% | 0.00% |
| 21 | Pictet Asset Management Holding SA | 958K | $106.3M | +43.6% | 1.396% | 0.10% |
| 22 | Jupiter Topco LLC | 925K | $102.8M | β | 1.349% | 0.04% |
| 23 | Woodline Partners LP | 759K | $84.3M | 0.0% | 1.106% | 0.26% |
| 24 | ALLIANCEBERNSTEIN L.P. | 895K | $77.8M | -1.7% | 1.304% | 0.03% |
| 25 | Clearbridge Investments, LLC | 696K | $77.3M | +14.3% | 1.015% | 0.06% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in RYTM β a direct measure of their conviction.
Filings activity in RYTM during Q2 2026, grouped by how each filer changed its position.
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q2 2026 | 306 | +6.6% | 112.88% | +4.80 pp | $8.26B | +32% |
| Q1 2026 | 287 | +3.6% | 108.08% | 2.47 pp | $6.26B | 18% |
| Q4 2025 | 277 | +6.5% | 110.55% | +5.78 pp | $7.63B | +8.5% |
| Q3 2025 | 260 | +16% | 104.77% | +1.03 pp | $7.03B | +74% |
| Q2 2025 | 225 | 0.4% | 103.74% | +1.76 pp | $4.03B | +22% |
| Q1 2025 | 226 | +11% | 101.98% | 2.53 pp | $3.29B | 6.8% |
| Q4 2024 | 203 | +16% | 104.51% | 6.47 pp | $3.53B | +1.7% |
| Q3 2024 | 175 | β | 110.98% | β | $3.48B | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying RYTM stock.
Based on Q2 2026 13F filings, institutional ownership of Rhythm Pharmaceuticals, Inc. stands at 112.9%, held across 306 reporting institutions.
RA CAPITAL MANAGEMENT, L.P. is the largest reported institutional holder of RYTM, with approximately 6,666,837 shares worth $0.74B as of Q2 2026.
Yes β 1 widely-followed marquee investor appear among the top 25 institutional holders of RYTM, including CITADEL ADVISORS LLC.
Our composite Smart Money Score for RYTM is 62 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
57 institutions opened new positions in RYTM during Q2 2026, while 40 fully exited. 190 added to existing positions and 47 trimmed.
RYTM institutional ownership rose by 4.80 percentage points quarter-over-quarter, with a net change of +19 holders.
The top 10 institutions account for 50.7% of all reported 13F value in RYTM, and the top 25 account for 75.6%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Rhythm Pharmaceuticals, Inc. (RYTM) Institutional Ownership