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Rhythm Pharmaceuticals

227 hedge funds and large institutions have $4.2B invested in Rhythm Pharmaceuticals in 2025 Q2 according to their latest regulatory filings, with 33 funds opening new positions, 93 increasing their positions, 74 reducing their positions, and 33 closing their positions.

New
Increased
Maintained
Reduced
Closed

43% more funds holding in top 10

Funds holding in top 10: 710 (+3)

26% more repeat investments, than reductions

Existing positions increased: 93 | Existing positions reduced: 74

22% more capital invested

Capital invested by funds: $3.44B → $4.2B (+$768M)

2.06% more ownership

Funds ownership: 102.53%104.59% (+2.1%)

0% more first-time investments, than exits

New positions opened: 33 | Existing positions closed: 33

0% less funds holding

Funds holding: 228227 (-1)

62% less call options, than puts

Call options by funds: $13.8M | Put options by funds: $36.7M

Holders
227
Holders Change
-1
Holders Change %
-0.44%
% of All Funds
2.99%
Holding in Top 10
10
Holding in Top 10 Change
+3
Holding in Top 10 Change %
+42.86%
% of All Funds
0.13%
New
33
Increased
93
Reduced
74
Closed
33
Calls
$13.8M
Puts
$36.7M
Net Calls
-$22.9M
Net Calls Change
-$40.9M
Name Holding Trade Value Shares
Change
Change in
Stake
BlackRock
1
BlackRock
New York
$396M -$36M -587,217 -9%
BBA
2
Baker Bros. Advisors
New York
$354M
RCM
3
RA Capital Management
Massachusetts
$351M -$32M -523,053 -9%
Primecap Management
4
Primecap Management
California
$308M -$55.7M -909,285 -16%
Vanguard Group
5
Vanguard Group
Pennsylvania
$227M +$8.83M +144,188 +4%
NMC
6
NEA Management Company
Maryland
$184M
PA
7
Perceptive Advisors
New York
$153M -$7.97M -130,146 -5%
Fidelity Investments
8
Fidelity Investments
Massachusetts
$123M +$16.2M +265,066 +16%
State Street
9
State Street
Massachusetts
$121M -$3.87M -63,132 -3%
Goldman Sachs
10
Goldman Sachs
New York
$110M +$5.87M +95,814 +6%
Federated Hermes
11
Federated Hermes
Pennsylvania
$107M +$5.79M +94,623 +6%
Westfield Capital Management
12
Westfield Capital Management
Massachusetts
$103M +$17.7M +288,376 +22%
Janus Henderson Group
13
Janus Henderson Group
United Kingdom
$89.3M -$14.9M -243,448 -15%
T. Rowe Price Associates
14
T. Rowe Price Associates
Maryland
$84.8M +$8.72M +142,339 +12%
Geode Capital Management
15
Geode Capital Management
Massachusetts
$82.9M +$1.47M +24,085 +2%
DCM
16
Driehaus Capital Management
Illinois
$80.2M -$11.5M -188,070 -13%
PCH
17
Polar Capital Holdings
United Kingdom
$79M +$46M +750,870 +150%
CC
18
Checkpoint Capital
California
$67M +$9.35M +152,760 +17%
Alkeon Capital Management
19
Alkeon Capital Management
New York
$64.3M +$12.2M +200,000 +24%
RSCM
20
Rock Springs Capital Management
Maryland
$54.4M +$1.65M +26,965 +3%
JP Morgan Chase
21
JP Morgan Chase
New York
$49.5M +$39.2M +639,919 +446%
Loomis, Sayles & Company
22
Loomis, Sayles & Company
Massachusetts
$37.4M -$876K -14,310 -2%
SI
23
Sofinnova Investments
California
$37M +$8.52M +139,171 +31%
Franklin Resources
24
Franklin Resources
California
$34.4M +$13.3M +217,642 +67%
HRCM
25
Hood River Capital Management
Florida
$34.4M -$7.09M -115,743 -18%

RYTM Hedge Fund Activity: Q2 2025 in Review

227 of the 7,595 institutional investors tracked by Wall St. Rank reported a position in Rhythm Pharmaceuticals (RYTM) for Q2 2025, worth a combined $4.2B — up 22% from $3.44B a quarter earlier.

Fund positioning in RYTM was balanced in Q2 2025: 33 funds opened new positions, 33 closed out, 93 added to existing stakes and 74 trimmed.

The largest buyer was Polar Capital Holdings, adding an estimated $46M. The largest seller was Primecap Management, cutting an estimated $55.7M.

  • 227 institutional investors held Rhythm Pharmaceuticals (RYTM) as of Q2 2025, down from 228 in Q1 2025.
  • Funds reported $4.2B of Rhythm Pharmaceuticals stock for Q2 2025, up 22% quarter-over-quarter.
  • 33 funds opened new Rhythm Pharmaceuticals positions in Q2 2025 and 33 closed out, a net change of 0 holders.
  • The largest Rhythm Pharmaceuticals buyer in Q2 2025 was Polar Capital Holdings, an estimated $46M added.
  • The largest Rhythm Pharmaceuticals seller in Q2 2025 was Primecap Management, an estimated $55.7M sold.

Based on aggregated 13F filings for Q2 2025.