Terminal · Institutions

Every 13F-reported equity position this quarter, with its quarter-over-quarter change — each row traces back to the SEC filing.

Siren, L.L.C. 13F Holdings -- Portfolio & Top Positions (2026-03-31)

Siren, L.L.C. (CIK 2005245) reported $3.61B across 93 reported positions in its SEC 13F filing for 2026-03-31. Largest positions: SRRK ($532.2M, 14.75%), KYMR ($265.4M, 7.36%), ERAS ($181.9M, 5.04%), EWTX ($139.6M, 3.87%), ONC ($138.1M, 3.83%). Source: SEC Form 13F.

RankTickerCompanyValue% PortfolioSharesAction
1SRRKScholar Rock Holding Corp$532.2M14.75%10.8MHold
2KYMRKymera Therapeutics Inc$265.4M7.36%3.2MTrimmed
3ERASErasca Inc$181.9M5.04%11.2MAdded
4EWTXEdgewise Therapeutics Inc$139.6M3.87%4.4MTrimmed
5ONCBeOne Medicines AG$138.1M3.83%465,000Trimmed
6TNGXTango Therapeutics Inc$118.3M3.28%5.7MTrimmed
7BCAXBicara Therapeutics Inc$115.4M3.20%5.8MAdded
8RVMDRevolution Medicines Inc$108.0M3.00%1.1MTrimmed
9ARWRArrowhead Pharmaceuticals Inc$101.3M2.81%1.6MAdded
10Veradermics Inc$95.1M2.64%1.5MNew
11XENEXenon Pharmaceuticals Inc$76.7M2.13%1.3MAdded
12OLMAOlema Pharmaceuticals Inc$70.9M1.97%4.8MAdded
13LXRXLexicon Pharmaceuticals Inc$69.1M1.92%44.3MAdded
14CRNXCrinetics Pharmaceuticals Inc$69.1M1.92%1.9MAdded
15COGTCogent Biosciences Inc$65.8M1.82%1.7MAdded
16STOKStoke Therapeutics Inc$65.0M1.80%2.0MTrimmed
17RCUSArcus Biosciences Inc$65.0M1.80%3.0MHold
18GPCRStructure Therapeutics Inc$64.0M1.78%1.3MAdded
19IRONDisc Medicine Inc$63.2M1.75%988,401Hold
20RYTMRhythm Pharmaceuticals Inc$63.1M1.75%725,511Added
21SLDBSolid Biosciences Inc$55.4M1.53%7.7MHold
22SEPNSepterna Inc$48.1M1.33%2.0MHold
23CNTACentessa Pharmaceuticals PLC$41.8M1.16%1.1MTrimmed
24SYRESpyre Therapeutics Inc$41.3M1.14%818,598Hold
25CYTKCytokinetics Inc$40.5M1.12%613,952New

Source: SEC Form 13F filings · as of 2026-03-31