Siren, L.L.C.
In its 13F for Q1 2025 (holdings as of March 31, 2025, filed May 23, 2025), Siren, L.L.C. reported 116 stock positions worth $1.8 billion. Its top holding was Scholar Rock (SRRK) at 16.8% of the portfolio, followed by Beone Medicines Ltd.-ADR (ONC, 7.7%) and Kymera Therapeutics (KYMR, 5.0%). Compared with Q4 2024, it opened 24 new positions, sold out of 25, added to 28 and reduced 40. The biggest buy was a new position in Blueprint Medicines (BPMC) and the biggest sale an exit from Argenx SE - ADR (ARGX).
- Most Recent 13F
- Q2 2026
- Location
- New York, NY
- CIK
- 0002005245
- Portfolio Value
- $1.8B (Q1 2025)
- SEC Filing
- 0002005245-25-000008 ↗ filed May 23, 2025
Holdings Value
Holdings 116 stocks · $1.8B
| SRRK Scholar Rock Holding Corp. | 16.78% | 9,250,005 | $297.4M | No change |
| ONC Beone Medicines Ltd.-ADR filed as BEIGENE LTD | 7.66% | 498,689 | $135.7M | Reduce -23.7% |
| KYMR Kymera Therapeutics Inc. | 5.00% | 3,240,313 | $88.7M | Add +9.1% |
| BPMC Blueprint Medicines Corp. | 3.63% | 726,167 | $64.3M | New |
| CRNX Crinetics Pharmaceuticals Inc. | 3.19% | 1,688,611 | $56.6M | Add +4.9% |
| APLS Apellis Pharmaceuticals Inc. | 3.18% | 2,578,396 | $56.4M | Reduce -8.4% |
| IRON Disc Medicine Inc. | 3.00% | 1,071,865 | $53.2M | New |
| SLNO Soleno Therapeutics Inc. | 2.93% | 727,337 | $52.0M | Add +106.7% |
| ASND Ascendis Pharma A/S | 2.53% | 287,366 | $44.8M | Reduce -3.4% |
| MRUS Merus NV | 2.48% | 1,043,467 | $43.9M | Add +33.0% |
| BCAX Bicara Therapeutics Inc. | 2.40% | 3,267,083 | $42.6M | Reduce -0.2% |
| CNTA Centessa Pharmaceuticals Ltd. | 2.40% | 2,960,029 | $42.6M | Reduce -1.5% |
| NAMS Newamsterdam Pharma Co. NV | 2.21% | 1,912,030 | $39.1M | Reduce -8.8% |
| EWTX Edgewise Therapeutics Inc. | 2.11% | 1,696,444 | $37.3M | Add +131.0% |
| ARWR Arrowhead Pharmaceuticals Inc. | 1.92% | 2,669,880 | $34.0M | Reduce -8.0% |
| RNAM Avidity Biosciences Inc. | 1.85% | 1,110,610 | $32.8M | Reduce -1.5% |
| WVE Wave Life Sciences Ltd. | 1.68% | 3,696,322 | $29.9M | Reduce -1.4% |
| TBLA Taboola.com Ltd. | 1.66% | 9,969,495 | $29.4M | No change |
| DYN Dyne Therapeutics Inc. | 1.60% | 2,717,987 | $28.4M | Add +101.7% |
| SLDB Solid Biosciences Inc. | 1.55% | 7,415,905 | $27.4M | Add +97.8% |
| XENE Xenon Pharmaceuticals Inc. | 1.39% | 732,761 | $24.6M | Reduce -1.5% |
| APGE Apogee Therapeutics Inc. | 1.25% | 594,994 | $22.2M | Reduce -20.4% |
| RVMD Revolution Medicines Inc. | 1.12% | 563,755 | $19.9M | Reduce -1.4% |
| TRVI Trevi Therapeutics Inc. | 1.02% | 2,863,793 | $18.0M | Reduce -1.4% |
| VERA Vera Therapeutics Inc. | 1.01% | 747,216 | $17.9M | Reduce -1.5% |
| LXRX Lexicon Pharmaceuticals Inc. | 1.01% | 38,918,903 | $17.9M | No change |
| PRTA Prothena Corp. PLC | 0.90% | 1,283,555 | $15.9M | Add +16.7% |
| BCYC Bicycle Therapeutics PLC-ADR | 0.87% | 1,812,752 | $15.4M | Reduce -1.4% |
| STOK Stoke Therapeutics Inc. | 0.84% | 2,247,347 | $14.9M | Add +12.4% |
| RYTM Rhythm Pharmaceuticals Inc. | 0.83% | 277,533 | $14.7M | New |
| SMMT Summit Therapeutics Inc. | 0.76% | 695,000 | $13.4M | New |
| SEPN Septerna Inc. | 0.72% | 2,202,514 | $12.8M | No change |
| RCUS Arcus Biosciences Inc. | 0.71% | 1,612,077 | $12.7M | No change |
| IHS Ihs Holding Ltd. | 0.69% | 2,357,520 | $12.3M | No change |
| ERAS Erasca Inc. | 0.68% | 8,757,249 | $12.0M | Reduce -1.1% |
| DNLI Denali Therapeutics Inc. | 0.63% | 821,513 | $11.2M | Reduce -1.5% |
| PCVX Vaxcyte Inc. | 0.63% | 295,543 | $11.2M | Reduce -1.5% |
| AMZN Amazon.com Inc. | 0.61% | 56,500 | $10.7M | Add +54.8% |
| MSFT Microsoft Corp. | 0.60% | 28,500 | $10.7M | Add +23.9% |
| RELY Remitly Global Inc. | 0.58% | 490,449 | $10.2M | No change |
| TSHA Taysha Gene Therapies Inc. | 0.51% | 6,514,737 | $9.1M | Reduce -1.3% |
| CGEM Cullinan Therapeutics Inc. | 0.51% | 1,193,410 | $9.0M | Reduce -1.5% |
| CRWD CrowdStrike Holdings Inc. Class A | 0.50% | 25,000 | $8.8M | Add +4.2% |
| SLN Silence Therapeutics PLC-ADR | 0.44% | 2,789,833 | $7.9M | Reduce -1.5% |
| GOOGL Alphabet Inc. Class A | 0.44% | 50,703 | $7.8M | Add +624.3% |
| RNAC Cartesian Therapeutics Inc. | 0.42% | 563,272 | $7.4M | Reduce -1.6% |
| ADBE Adobe Inc. | 0.42% | 19,298 | $7.4M | Add +119.3% |
| KRRO Korro Bio Inc. | 0.41% | 418,833 | $7.3M | No change |
| NOW ServiceNow Inc. | 0.41% | 9,126 | $7.3M | Add +62.8% |
| SEER Seer Inc. | 0.38% | 4,000,000 | $6.8M | No change |
| PDD PDD Holdings Inc. | 0.35% | 52,901 | $6.3M | No change |
| SYRE Spyre Therapeutics Inc. | 0.34% | 368,598 | $5.9M | Reduce -1.4% |
| GOSS Gossamer Bio Inc. | 0.32% | 5,208,968 | $5.7M | No change |
| ORIC Oric Pharmaceuticals Inc. | 0.32% | 1,007,575 | $5.6M | No change |
| UPB Upstream Bio Inc. | 0.27% | 788,450 | $4.8M | Reduce -1.4% |
| NVDA Nvidia Corp. | 0.27% | 44,432 | $4.8M | Reduce -9.2% |
| TSM Taiwan Semiconductor-SP ADR | 0.27% | 28,500 | $4.7M | Add +90.0% |
| DDOG Datadog Inc. Class A | 0.27% | 47,425 | $4.7M | Add +55.9% |
| NMRA Neumora Therapeutics Inc. | 0.25% | 4,358,283 | $4.4M | Reduce -0.9% |
| FROG Jfrog Ltd. | 0.24% | 131,616 | $4.2M | Add +9.6% |
| DT Dynatrace Inc. | 0.23% | 87,729 | $4.1M | Add +6.0% |
| MTSR Metsera Inc. | 0.23% | 150,000 | $4.1M | New |
| RCKT Rocket Pharmaceuticals Inc. | 0.22% | 591,263 | $3.9M | Reduce -1.5% |
| CRM Salesforce Inc. | 0.22% | 14,600 | $3.9M | New |
| EDU New Oriental Educatio-SP ADR | 0.21% | 79,500 | $3.8M | Add +16.1% |
| RAPP Rapport Therapeutics Inc. | 0.21% | 378,469 | $3.8M | Reduce -1.5% |
| IONQ Ionq Inc. | 0.21% | 170,000 | $3.8M | No change |
| IGMS Igm Biosciences Inc. | 0.21% | 3,255,826 | $3.7M | Reduce -2.2% |
| WHWK Whitehawk Therapeutics Inc. | 0.21% | 2,082,000 | $3.7M | New |
| TIL Instil Bio Inc. | 0.20% | 203,933 | $3.5M | Add +6.0% |
| TNGX Tango Therapeutics Inc. | 0.20% | 2,565,342 | $3.5M | Reduce -1.5% |
| VIGL Vigil Neuroscience Inc. | 0.20% | 1,967,064 | $3.5M | Reduce -1.2% |
| SION Sionna Therapeutics Inc. | 0.19% | 325,000 | $3.4M | New |
| NBIS Nebius Group NV | 0.17% | 140,000 | $3.0M | Add +16.7% |
| FHTX Foghorn Therapeutics Inc. | 0.15% | 720,720 | $2.6M | No change |
| RDDT Reddit Inc. Class A | 0.14% | 23,500 | $2.5M | New |
| LPLA LPL Financial Holdings Inc. | 0.14% | 7,500 | $2.5M | New |
| SGMT Sagimet Biosciences Inc. Class A | 0.13% | 724,771 | $2.4M | No change |
| ELDN Eledon Pharmaceuticals Inc. | 0.13% | 690,170 | $2.3M | New |
| TSLA Tesla Inc. | 0.13% | 9,000 | $2.3M | New |
| KLRS Kalaris Therapeutics Inc. | 0.13% | 282,586 | $2.3M | New |
| MRVL Marvell Technology Inc. | 0.13% | 36,808 | $2.3M | Add +636.2% |
| QCOM Qualcomm Inc. | 0.12% | 14,000 | $2.2M | Reduce -6.7% |
| BEKE Ke Holdings Inc.-ADR filed as KE HLDGS INC | 0.12% | 105,000 | $2.1M | Add +75.0% |
| LXEO Lexeo Therapeutics Inc. | 0.12% | 603,435 | $2.1M | No change |
| PRQR Proqr Therapeutics NV | 0.12% | 1,552,183 | $2.1M | Reduce -1.4% |
| PANW Palo Alto Networks Inc. | 0.11% | 11,500 | $2.0M | Add +91.7% |
| SAIL Sailpoint Inc. | 0.10% | 95,000 | $1.8M | New |
| BDTX Black Diamond Therapeutics I | 0.09% | 1,046,517 | $1.6M | No change |
| SARO Standardaero Inc. | 0.09% | 56,855 | $1.5M | New |
| BIOA Bioage Labs Inc. | 0.08% | 382,406 | $1.4M | Reduce -1.4% |
| TRML Tourmaline Bio Inc. | 0.08% | 91,426 | $1.4M | No change |
| WK Workiva Inc. | 0.07% | 17,500 | $1.3M | Add +75.0% |
| BILL Bill Holdings Inc. | 0.07% | 28,500 | $1.3M | New |
| PYPL PayPal Holdings Inc. | 0.07% | 20,000 | $1.3M | Add +33.3% |
| GBIO Generation Bio Co. | 0.07% | 2,968,925 | $1.2M | Reduce -0.5% |
| SEMR Semrush Holdings Inc. Class A | 0.07% | 125,000 | $1.2M | Add +257.1% |
| PEGA Pegasystems Inc. | 0.06% | 16,500 | $1.1M | New |
| MDB Mongodb Inc. | 0.05% | 5,500 | $965K | New |
| NKE Nike Inc. Class B | 0.05% | 15,000 | $952K | New |
Portfolio Sells Q4 2024 → Q1 2025
| ARGX Argenx SE - ADR | Sold out | 0.00% | −3.13 |
| SWTX Springworks Therapeutics Inc. | Sold out | 0.00% | −2.20 |
| NMRA Neumora Therapeutics Inc. | Reduce -0.9% | 0.25% | −1.81 |
| MDGL Madrigal Pharmaceuticals Inc. | Sold out | 0.00% | −1.72 |
| CYTK Cytokinetics Inc. | Sold out | 0.00% | −0.84 |
| APLS Apellis Pharmaceuticals Inc. | Reduce -8.4% | 3.18% | −0.79 |
| IGMS Igm Biosciences Inc. | Reduce -2.2% | 0.21% | −0.69 |
| KURA Kura Oncology Inc. | Sold out | 0.00% | −0.52 |
| ARWR Arrowhead Pharmaceuticals Inc. | Reduce -8.0% | 1.92% | −0.49 |
| PCVX Vaxcyte Inc. | Reduce -1.5% | 0.63% | −0.46 |
| SLN Silence Therapeutics PLC-ADR | Reduce -1.5% | 0.44% | −0.42 |
| JANX Janux Therapeutics Inc. | Sold out | 0.00% | −0.41 |
| VERA Vera Therapeutics Inc. | Reduce -1.5% | 1.01% | −0.40 |
| IONS Ionis Pharmaceuticals Inc. | Sold out | 0.00% | −0.39 |
| WVE Wave Life Sciences Ltd. | Reduce -1.4% | 1.68% | −0.37 |
| IOVA Iovance Biotherapeutics Inc. | Sold out | 0.00% | −0.36 |
| UPB Upstream Bio Inc. | Reduce -1.4% | 0.27% | −0.31 |
| ERAS Erasca Inc. | Reduce -1.1% | 0.68% | −0.31 |
| BCYC Bicycle Therapeutics PLC-ADR | Reduce -1.4% | 0.87% | −0.27 |
| APGE Apogee Therapeutics Inc. | Reduce -20.4% | 1.25% | −0.24 |
| SLRN Acelyrin Inc. | Sold out | 0.00% | −0.24 |
| NAMS Newamsterdam Pharma Co. NV | Reduce -8.8% | 2.21% | −0.17 |
| PHAT Phathom Pharmaceuticals Inc. | Sold out | 0.00% | −0.17 |
| TNGX Tango Therapeutics Inc. | Reduce -1.5% | 0.20% | −0.16 |
| BA The Boeing Co. | Reduce -80.0% | 0.05% | −0.15 |
| CGEM Cullinan Therapeutics Inc. | Reduce -1.5% | 0.51% | −0.14 |
| FCX Freeport-McMoran Inc. | Sold out | 0.00% | −0.13 |
| ALLOVIR INC | Sold out | 0.00% | −0.12 |
| DNLI Denali Therapeutics Inc. | Reduce -1.5% | 0.63% | −0.12 |
| BCAX Bicara Therapeutics Inc. | Reduce -0.2% | 2.40% | −0.12 |
| OVID Ovid Therapeutics Inc. | Sold out | 0.00% | −0.12 |
| SE Sea Ltd.-ADR | Sold out | 0.00% | −0.12 |
| RCKT Rocket Pharmaceuticals Inc. | Reduce -1.5% | 0.22% | −0.11 |
| ESTC Elastic NV | Sold out | 0.00% | −0.11 |
| RGNX Regenxbio Inc. | Sold out | 0.00% | −0.10 |
| RAPP Rapport Therapeutics Inc. | Reduce -1.5% | 0.21% | −0.09 |
| GBIO Generation Bio Co. | Reduce -0.5% | 0.07% | −0.07 |
| PRQR Proqr Therapeutics NV | Reduce -1.4% | 0.12% | −0.07 |
| APLT Applied Therapeutics Inc. | Sold out | 0.00% | −0.06 |
| HCA HCA Healthcare Inc. | Sold out | 0.00% | −0.05 |
| SYRE Spyre Therapeutics Inc. | Reduce -1.4% | 0.34% | −0.05 |
| OMGAQ Omega Therapeutics Inc. | Sold out | 0.00% | −0.04 |
| ACHL Achilles Therapeutics PL-ADR | Sold out | 0.00% | −0.04 |
| RNAC Cartesian Therapeutics Inc. | Reduce -1.6% | 0.42% | −0.03 |
| DLTR Dollar Tree Inc. | Sold out | 0.00% | −0.03 |
| PCOR Procore Technologies Inc. | Reduce -50.0% | 0.04% | −0.03 |
| META Meta Platforms Inc. Class A | Sold out | 0.00% | −0.03 |
| NU Nu Holdings Ltd./Cayman Isl-A | Sold out | 0.00% | −0.02 |
| MNDY Monday.com Ltd. | Sold out | 0.00% | −0.02 |
| NVDA Nvidia Corp. | Reduce -9.2% | 0.27% | −0.02 |
Portfolio Buys Q4 2024 → Q1 2025
| BPMC Blueprint Medicines Corp. | New | 3.63% | +3.63 |
| IRON Disc Medicine Inc. | New | 3.00% | +3.00 |
| SLNO Soleno Therapeutics Inc. | Add +106.7% | 2.93% | +2.23 |
| EWTX Edgewise Therapeutics Inc. | Add +131.0% | 2.11% | +1.24 |
| MRUS Merus NV | Add +33.0% | 2.48% | +1.02 |
| SLDB Solid Biosciences Inc. | Add +97.8% | 1.55% | +0.89 |
| RYTM Rhythm Pharmaceuticals Inc. | New | 0.83% | +0.83 |
| SMMT Summit Therapeutics Inc. | New | 0.76% | +0.76 |
| GOOGL Alphabet Inc. Class A | Add +624.3% | 0.44% | +0.38 |
| AMZN Amazon.com Inc. | Add +54.8% | 0.61% | +0.25 |
| ADBE Adobe Inc. | Add +119.3% | 0.42% | +0.24 |
| MTSR Metsera Inc. | New | 0.23% | +0.23 |
| PRTA Prothena Corp. PLC | Add +16.7% | 0.90% | +0.22 |
| CRM Salesforce Inc. | New | 0.22% | +0.22 |
| WHWK Whitehawk Therapeutics Inc. | New | 0.21% | +0.21 |
| DYN Dyne Therapeutics Inc. | Add +101.7% | 1.60% | +0.20 |
| SION Sionna Therapeutics Inc. | New | 0.19% | +0.19 |
| MSFT Microsoft Corp. | Add +23.9% | 0.60% | +0.18 |
| NOW ServiceNow Inc. | Add +62.8% | 0.41% | +0.15 |
| RDDT Reddit Inc. Class A | New | 0.14% | +0.14 |
| LPLA LPL Financial Holdings Inc. | New | 0.14% | +0.14 |
| TSM Taiwan Semiconductor-SP ADR | Add +90.0% | 0.27% | +0.14 |
| CRWD CrowdStrike Holdings Inc. Class A | Add +4.2% | 0.50% | +0.13 |
| ELDN Eledon Pharmaceuticals Inc. | New | 0.13% | +0.13 |
| TSLA Tesla Inc. | New | 0.13% | +0.13 |
| KLRS Kalaris Therapeutics Inc. | New | 0.13% | +0.13 |
| MRVL Marvell Technology Inc. | Add +636.2% | 0.13% | +0.10 |
| SAIL Sailpoint Inc. | New | 0.10% | +0.10 |
| SARO Standardaero Inc. | New | 0.09% | +0.09 |
| FROG Jfrog Ltd. | Add +9.6% | 0.24% | +0.08 |
| BILL Bill Holdings Inc. | New | 0.07% | +0.07 |
| DDOG Datadog Inc. Class A | Add +55.9% | 0.27% | +0.07 |
| BEKE Ke Holdings Inc.-ADR | Add +75.0% | 0.12% | +0.07 |
| PEGA Pegasystems Inc. | New | 0.06% | +0.06 |
| PANW Palo Alto Networks Inc. | Add +91.7% | 0.11% | +0.06 |
| MDB Mongodb Inc. | New | 0.05% | +0.05 |
| NKE Nike Inc. Class B | New | 0.05% | +0.05 |
| INFA Informatica Inc. Class A | New | 0.05% | +0.05 |
| SEMR Semrush Holdings Inc. Class A | Add +257.1% | 0.07% | +0.05 |
| AGEN Agenus Inc. | New | 0.04% | +0.04 |
| TIL Instil Bio Inc. | Add +6.0% | 0.20% | +0.04 |
| DT Dynatrace Inc. | Add +6.0% | 0.23% | +0.03 |
| DECK Deckers Outdoor Corp. | New | 0.03% | +0.03 |
| USB US Bancorp | New | 0.03% | +0.03 |
| WK Workiva Inc. | Add +75.0% | 0.07% | +0.03 |
| EDU New Oriental Educatio-SP ADR | Add +16.1% | 0.21% | +0.02 |
| NBIS Nebius Group NV | Add +16.7% | 0.17% | +0.02 |
| GDS GDS Holdings Ltd. - ADR | New | 0.02% | +0.02 |
| PYPL PayPal Holdings Inc. | Add +33.3% | 0.07% | +0.02 |
| STOK Stoke Therapeutics Inc. | Add +12.4% | 0.84% | −0.13 |
Options Activity Q4 2024 → Q1 2025
| GOSS Gossamer Bio Inc. | call | Sold out | 207,000 | $187Kbefore exit |
Calls and puts are listed by the shares they cover; their value is not part of the stock holdings above.
All Filings
| Quarter | Positions | 13F Reported Value | Top Holdings |
|---|---|---|---|
| Q2 2026 | 115 | $4.9B | SRRK, KYMR, ERAS, MANE, TNGX |
| Q1 2026 | 100 | $3.6B | SRRK, KYMR, ERAS, EWTX, ONC |
| Q4 2025 | 113 | $3.4B | SRRK, KYMR, ONC, EWTX, RVMD |
| Q3 2025 | 115 | $2.6B | SRRK, KYMR, ONC, ARWR, BCAX |
| Q2 2025 | 110 | $1.9B | SRRK, KYMR, ONC, IRON, CRNX |
| Q1 2025Amended | 116 | $1.8B | SRRK, ONC, KYMR, BPMC, CRNX |
| Q4 2024 | 117 | $2.3B | SRRK, ONC, KYMR, APLS, CRNX |
| Q3 2024 | 109 | $2.0B | KYMR, ONC, SRRK, BCAX, ARGX |