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Rhythm Pharmaceuticals
RYTM

279 hedge funds and large institutions have $7.8B invested in Rhythm Pharmaceuticals in 2025 Q4 according to their latest regulatory filings, with 57 funds opening new positions, 106 increasing their positions, 89 reducing their positions, and 40 closing their positions.

New
Increased
Maintained
Reduced
Closed

43% more first-time investments, than exits

New positions opened: 57 | Existing positions closed: 40

41% more call options, than puts

Call options by funds: $45.9M | Put options by funds: $32.5M

19% more repeat investments, than reductions

Existing positions increased: 106 | Existing positions reduced: 89

8% more capital invested

Capital invested by funds: $7.2B → $7.8B (+$598M)

6% more funds holding

Funds holding: 264 → 279 (+15)

2.45% more ownership

Funds ownership: 106.73% → 109.17% (+2.4%)

0% more funds holding in top 10

Funds holding in top 10: 10 → 10 (0)

Holders
279
Holders Change
+15
Holders Change %
+5.68%
% of All Funds
3.39%
Holding in Top 10
10
Holding in Top 10 Change
–
Holding in Top 10 Change %
–
% of All Funds
0.12%
New
57
Increased
106
Reduced
89
Closed
40
Calls
$45.9M
Puts
$32.5M
Net Calls
+$13.5M
Net Calls Change
-$21.7M

Top Buyers

1
Vanguard Group
Vanguard Group
Pennsylvania
+$129M
2
RCM
RA Capital Management
Massachusetts
+$105M
3
Jennison Associates
Jennison Associates
New York
+$53.8M
4
Point72 Asset Management
Point72 Asset Management
Connecticut
+$45.6M
5
Capital Research Global Investors
Capital Research Global Investors
California
+$41M

Top Sellers

1
Alkeon Capital Management
Alkeon Capital Management
New York
-$103M
2
Primecap Management
Primecap Management
California
-$83.2M
3
Fidelity Investments
Fidelity Investments
Massachusetts
-$46.6M
4
Voloridge Investment Management
Voloridge Investment Management
Florida
-$32.6M
5
Balyasny Asset Management
Balyasny Asset Management
Illinois
-$29.5M
Name Holding Trade Value Shares
Change 		Change in
Stake
BHWM
276
Bay Harbor Wealth Management
Maryland
$107 +$106 +1 New
TPCW
277
TD Private Client Wealth
New York
$107 +$106 +1 New
DF
278
Dunhill Financial
United Kingdom
$65 +$106 +1 New
Alkeon Capital Management
279
Alkeon Capital Management
New York
– -$103M -1,017,700 Closed
Assenagon Asset Management
280
Assenagon Asset Management
Luxembourg
– -$22.6M -224,128 Closed
Marshall Wace
281
Marshall Wace
United Kingdom
– -$17.4M -171,834 Closed
PAM
282
Panagora Asset Management
Massachusetts
– -$6.53M -64,614 Closed
Walleye Capital
283
Walleye Capital
New York
– -$5.07M -50,181 Closed
ACM
284
Aquatic Capital Management
Illinois
– -$4.29M -42,490 Closed
TI
285
Trexquant Investment
Connecticut
– -$3.75M -37,161 Closed
Canada Pension Plan Investment Board
286
Canada Pension Plan Investment Board
Ontario, Canada
– -$3.74M -37,000 Closed
JG
287
Jain Global
New York
– -$3.55M -35,110 Closed
AA
288
ALPS Advisors
Colorado
– -$3.33M -33,000 Closed
SB
289
Samsara BioCapital
California
– -$3.06M -30,285 Closed
DFCM
290
Dark Forest Capital Management
Puerto Rico
– -$2.89M -28,639 Closed
Aberdeen Group
291
Aberdeen Group
United Kingdom
– -$2.7M -26,740 Closed
BGM
292
Burkehill Global Management
New York
– -$2.02M -20,000 Closed
Schroder Investment Management Group
293
Schroder Investment Management Group
United Kingdom
– -$1.82M -18,042 Closed
EGM
294
Engineers Gate Manager
New York
– -$1.39M -13,775 Closed
Zurich Cantonal Bank
295
Zurich Cantonal Bank
Switzerland
– -$1.14M -10,726 Closed
FT
296
Fiduciary Trust
Massachusetts
– -$1.01M -10,000 Closed
RAM
297
Readystate Asset Management
Illinois
– -$845K -8,365 Closed
AIM
298
Aigen Investment Management
New York
– -$831K -8,225 Closed
I
299
InceptionR
California
– -$756K -7,482 Closed
Arrowstreet Capital
300
Arrowstreet Capital
Massachusetts
– -$637K -6,307 Closed
9 10 11
12
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RYTM Hedge Fund Activity: Q4 2025 in Review

279 of the 8,223 institutional investors tracked by Wall St. Rank reported a position in Rhythm Pharmaceuticals (RYTM) for Q4 2025, worth a combined $7.8B — up 8.3% from $7.2B a quarter earlier.

Buyers outnumbered sellers: 57 funds opened new RYTM positions and 40 closed out — a net gain of 17 holders — while 106 added to existing stakes and 89 trimmed.

The largest buyer was Vanguard Group, adding an estimated $129M. The largest seller was Alkeon Capital Management, exiting entirely with an estimated $103M sold.

  • 279 institutional investors held Rhythm Pharmaceuticals (RYTM) as of Q4 2025, up from 264 in Q3 2025.
  • Funds reported $7.8B of Rhythm Pharmaceuticals stock for Q4 2025, up 8.3% quarter-over-quarter.
  • 57 funds opened new Rhythm Pharmaceuticals positions in Q4 2025 and 40 closed out, a net change of +17 holders.
  • The largest Rhythm Pharmaceuticals buyer in Q4 2025 was Vanguard Group, an estimated $129M added.
  • The largest Rhythm Pharmaceuticals seller in Q4 2025 was Alkeon Capital Management, an estimated $103M sold.

Based on aggregated 13F filings for Q4 2025.