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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
Neuberger Berman Group
76
Neuberger Berman Group
New York
$7.88M -$1.22M -11,545 -14%
Wells Fargo
77
Wells Fargo
California
$7.77M +$2.7M +25,483 +54%
Balyasny Asset Management
78
Balyasny Asset Management
Illinois
$7.74M -$29.5M -277,726 -79%
RhumbLine Advisers
79
RhumbLine Advisers
Massachusetts
$7.62M -$1.15M -10,856 -13%
AQR Capital Management
80
AQR Capital Management
Connecticut
$7.5M -$1.03M -9,734 -12%
NCM
81
NEXTBio Capital Management
California
$7.23M +$7.17M +67,586 New
Norges Bank
82
Norges Bank
Norway
$7.09M +$7.02M +66,213 New
CM
83
Castleark Management
Illinois
$6.9M +$2.33M +21,940 +52%
Voloridge Investment Management
84
Voloridge Investment Management
Florida
$6.48M -$32.6M -307,688 -84%
Manulife (Manufacturers Life Insurance)
85
Manulife (Manufacturers Life Insurance)
Ontario, Canada
$6.37M -$139K -1,308 -2%
PP
86
PDT Partners
New York
$6.36M -$2.83M -26,700 -31%
SC
87
Stempoint Capital
New York
$6.31M -$3.45M -32,529 -36%
EI
88
EAM Investors
California
$6.14M -$122K -1,153 -2%
Rafferty Asset Management
89
Rafferty Asset Management
New York
$5.94M -$22.1K -208 -0.4%
Legal & General Group
90
Legal & General Group
United Kingdom
$5.9M -$244K -2,301 -4%
TD Asset Management
91
TD Asset Management
Ontario, Canada
$5.89M -$479K -4,514 -8%
California State Teachers Retirement System (CalSTRS)
92
California State Teachers Retirement System (CalSTRS)
California
$5.73M +$488K +4,603 +9%
GIM
93
Granahan Investment Management
Massachusetts
$5.72M +$395K +3,724 +7%
Prudential Financial
94
Prudential Financial
New Jersey
$5.69M -$2.11M -19,865 -27%
ACM
95
ADAR1 Capital Management
Texas
$5.5M +$189K +1,778 +4%
NFGH
96
Nan Fung Group Holdings
Hong Kong
$5.26M – – –
Victory Capital Management
97
Victory Capital Management
Texas
$4.86M +$265K +2,498 +6%
WCM Investment Management
98
WCM Investment Management
California
$4.78M -$311K -2,928 -6%
HIS
99
Harvest Investment Services
Illinois
$4.7M -$444K -4,187 -9%
HS
100
HighVista Strategies
Massachusetts
$4.59M +$571K +5,385 +14%
2 3
4
5 6

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.