Siren, L.L.C.
•CIK: 2005245•Filing: Q4 2025
Siren, L.L.C., managed by the renowned hedge fund duo of John Paulson and Ed Thorp, is known for its quantitative and macroeconomic strategies, currently holding $3.4 billion in assets with a focus on biotech and healthcare sectors. Recently, the fund has made notable moves by adding SYRE and RAPT, which have surged by 334% and 211% respectively, while exiting positions in RNAM and RZLT.
Total AUM
$3.4B
QoQ Performance
+31.1%
Positions
113
Top 10 Concentration
46.3%
Latest Filing
Q4 2025
Top Holdings Allocation
SRRK
KYMR
SRRK14.2%
KYMR7.6%
ONC4.5%
EWTX3.4%
RVMD3.2%
CNTA3.0%
ARWR3.0%
BCAX2.6%
📈 Biggest Buys
📉 Biggest Sells
Sector Breakdown
Other98.4%
Technology1.2%
Consumer0.4%
🚪 Exited Positionssold since Q3 2025
+23 more exited positions
Changes from Q3 2025
NEW26 new positions
↑30 increased
↓24 decreased
Historical Filings
Q4 2025Q3 2025Q2 2025Q1 2025Q4 2024Q3 2024