Rhythm Pharmaceuticals
RYTM
264 hedge funds and large institutions have $7.2B invested in Rhythm Pharmaceuticals in 2025 Q3 according to their latest regulatory filings, with 57 funds opening new positions, 99 increasing their positions, 82 reducing their positions, and 17 closing their positions.
235% more first-time investments, than exits
New positions opened: 57 | Existing positions closed: 17
232% more call options, than puts
Call options by funds: $50.3M | Put options by funds: $15.2M
71% more capital invested
Capital invested by funds: $4.2B → $7.2B (+$3B)
21% more repeat investments, than reductions
Existing positions increased: 99 | Existing positions reduced: 82
16% more funds holding
Funds holding: 227 → 264 (+37)
2.14% more ownership
Funds ownership: 104.59% → 106.73% (+2.1%)
0% more funds holding in top 10
Funds holding in top 10: 10 → 10 (0)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Vanguard Group
Malvern,
Pennsylvania
|
+$131M |
| 2 |
AllianceBernstein
Nashville,
Tennessee
|
+$85.2M |
| 3 |
Capital Research Global Investors
Los Angeles,
California
|
+$55.5M |
| 4 |
Jennison Associates
New York
|
+$38.2M |
| 5 |
JP Morgan Chase
New York
|
+$37.6M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Primecap Management
Pasadena,
California
|
-$57.1M |
| 2 |
Westfield Capital Management
Boston,
Massachusetts
|
-$52M |
| 3 |
SI
Sofinnova Investments
Menlo Park,
California
|
-$31.5M |
| 4 |
HRCM
Hood River Capital Management
Palm Beach Gardens,
Florida
|
-$28.6M |
| 5 |
CC
Checkpoint Capital
San Francisco,
California
|
-$27.5M |
RYTM Hedge Fund Activity: Q3 2025 in Review
264 of the 7,620 institutional investors tracked by Wall St. Rank reported a position in Rhythm Pharmaceuticals (RYTM) for Q3 2025, worth a combined $7.2B — up 71% from $4.2B a quarter earlier.
Buyers outnumbered sellers: 57 funds opened new RYTM positions and 17 closed out — a net gain of 40 holders — while 99 added to existing stakes and 82 trimmed.
The largest buyer was Vanguard Group, adding an estimated $131M. The largest seller was Primecap Management, cutting an estimated $57.1M.
- 264 institutional investors held Rhythm Pharmaceuticals (RYTM) as of Q3 2025, up from 227 in Q2 2025.
- Funds reported $7.2B of Rhythm Pharmaceuticals stock for Q3 2025, up 71% quarter-over-quarter.
- 57 funds opened new Rhythm Pharmaceuticals positions in Q3 2025 and 17 closed out, a net change of +40 holders.
- The largest Rhythm Pharmaceuticals buyer in Q3 2025 was Vanguard Group, an estimated $131M added.
- The largest Rhythm Pharmaceuticals seller in Q3 2025 was Primecap Management, an estimated $57.1M sold.
Based on aggregated 13F filings for Q3 2025.