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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
RCM
1
RA Capital Management
Massachusetts
$714M +$105M +985,478 +17%
BlackRock
2
BlackRock
New York
$674M -$518K -4,881 -0.1%
Vanguard Group
3
Vanguard Group
Pennsylvania
$665M +$129M +1,214,489 +24%
BBA
4
Baker Bros. Advisors
New York
$600M – – –
Primecap Management
5
Primecap Management
California
$372M -$83.2M -784,190 -18%
NMC
6
NEA Management Company
Maryland
$311M – – –
PA
7
Perceptive Advisors
New York
$273M +$11.4M +107,422 +4%
State Street
8
State Street
Massachusetts
$235M +$18M +169,964 +8%
Goldman Sachs
9
Goldman Sachs
New York
$196M -$6.66M -62,797 -3%
Fidelity Investments
10
Fidelity Investments
Massachusetts
$183M -$46.6M -438,866 -20%
Federated Hermes
11
Federated Hermes
Pennsylvania
$174M -$11M -104,044 -6%
T. Rowe Price Associates
12
T. Rowe Price Associates
Maryland
$167M +$17.1M +160,950 +11%
JP Morgan Chase
13
JP Morgan Chase
New York
$152M +$25M +235,920 +20%
Geode Capital Management
14
Geode Capital Management
Massachusetts
$147M +$1.37M +12,900 +0.9%
DCM
15
Driehaus Capital Management
Illinois
$138M -$10.5M -98,553 -7%
Westfield Capital Management
16
Westfield Capital Management
Massachusetts
$136M +$21M +198,154 +19%
PCH
17
Polar Capital Holdings
United Kingdom
$127M -$6.32M -59,540 -5%
Janus Henderson Group
18
Janus Henderson Group
United Kingdom
$121M -$3.69M -34,762 -3%
CC
19
Checkpoint Capital
California
$106M +$24.2M +228,493 +30%
Capital Research Global Investors
20
Capital Research Global Investors
California
$105M +$41M +386,839 +65%
AllianceBernstein
21
AllianceBernstein
Tennessee
$99.6M -$5.25M -49,449 -5%
Jennison Associates
22
Jennison Associates
New York
$98.3M +$53.8M +507,017 +123%
Franklin Resources
23
Franklin Resources
California
$74.5M +$13.6M +127,953 +23%
RSCM
24
Rock Springs Capital Management
Maryland
$74.4M -$2.34M -22,092 -3%
WP
25
Woodline Partners
California
$73.7M +$11.5M +108,596 +19%
1
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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.