Siren, L.L.C. Portfolio Stock Holdings

According to the SEC 13F filed on August 13, 2026, Siren, L.L.C. disclosed 103 stock positions valued at approximately $4.93B as of quarter-end June 30, 2026. The largest holdings include Scholar Rock Holding Corp, Kymera Therapeutics Inc, and Erasca Inc.

Report Period
June 30, 2026
No. of Stocks
103
Portfolio Value
$4.93B
Holdings by Sector
Siren, L.L.C. Portfolio Holdings in Q2 2026
CompanySymbolSectorPortfolio %SharesChange (Shares)Change %Value
Scholar Rock Holding CorpSRRKHealthcare10.69%9,575,013-1,250,000-11.55%$526,625,715
Kymera Therapeutics IncKYMRHealthcare6.83%2,935,830-251,000-7.88%$336,651,626
Erasca IncERASHealthcare4.24%11,397,781+153,535+1.37%$208,807,348
Tango Therapeutics IncTNGXHealthcare3.92%6,179,364+522,259+9.23%$193,166,919
Revolution Medicines IncRVMDHealthcare3.42%900,000-210,980-18.99%$168,552,000
Bicara Therapeutics IncBCAXOther3.38%5,602,970-200,000-3.45%$166,352,179
Arrowhead Pharmaceuticals IncARWRHealthcare2.84%1,715,476+100,000+6.19%$139,828,449
BeOne Medicines AGBGNEHealthcare2.69%465,000--$132,511,050
Edgewise Therapeutics IncEWTXHealthcare2.63%3,184,629-1,245,634-28.12%$129,391,476
Rhythm Pharmaceuticals IncRYTMHealthcare2.56%1,136,275+410,764+56.62%$126,160,613
Lexicon Pharmaceuticals IncLXRXHealthcare2.16%44,303,518--$106,328,443
Enliven Therapeutics IncELVNHealthcare1.83%1,774,411+1,028,185+137.78%$90,051,358
Spyre Therapeutics IncSYREHealthcare1.75%968,598+150,000+18.32%$85,992,130
Parabilis Medicines IncPBLSOther1.66%2,992,259+2,992,259+100.00%$81,898,129
Xenon Pharmaceuticals IncXENEHealthcare1.62%1,318,564--$79,588,523
Solid Biosciences IncSLDBHealthcare1.56%7,690,405--$76,827,146
Abivax SAABVXHealthcare1.56%576,000+576,000+100.00%$76,757,760
Arcus Biosciences IncRCUSHealthcare1.51%2,420,430-586,647-19.51%$74,621,857
Cogent Biosciences IncCOGTHealthcare1.46%1,859,279+150,000+8.78%$71,954,097
Relay Therapeutics IncRLAYHealthcare1.39%3,650,000+3,650,000+100.00%$68,291,500
Taysha Gene Therapies IncTSHAHealthcare1.36%9,846,579+1,016,666+11.51%$67,055,203
Definium Therapeutics IncDFTXOther1.36%1,419,493+500,000+54.38%$66,772,951
Stoke Therapeutics IncSTOKHealthcare1.33%1,995,347--$65,287,754
Disc Medicine IncIRONHealthcare1.32%888,401-100,000-10.12%$64,977,649
Cytokinetics IncCYTKHealthcare1.31%758,952+145,000+23.62%$64,655,121
Septerna IncSEPNOther1.29%1,900,000-100,000-5.00%$63,631,000
Olema Pharmaceuticals IncOLMAHealthcare1.23%4,856,949+100,000+2.10%$60,760,432
Crinetics Pharmaceuticals IncCRNXHealthcare1.08%1,420,788-482,848-25.36%$53,165,887
Kailera Therapeutics IncKLRAOther0.99%2,214,286+2,214,286+100.00%$48,780,721
Dyne Therapeutics, IncDYNHealthcare0.96%2,129,125-100,000-4.49%$47,287,866
Showing 30 of 103 holdings in the latest reporting period.
Siren, L.L.C. Options Holdings in Q2 2026
QuarterSymbolCompanyOptionContractsNotional Value
Q2 2026MSFTMicrosoft CorporationCALL24,000$8,952,480
Q2 2026AAPLApple Inc.CALL23,000$6,655,280
Showing 2 of 2 options positions in the latest reporting period.

Notional value represents the total exposure of the options position.