Siren, L.L.C.

In its 13F for Q3 2025 (holdings as of September 30, 2025, filed November 13, 2025), Siren, L.L.C. reported 115 stock positions worth $2.6 billion. Its top holding was Scholar Rock (SRRK) at 13.5% of the portfolio, followed by Kymera Therapeutics (KYMR, 7.6%) and Beone Medicines Ltd.-ADR (ONC, 6.6%). Compared with Q2 2025, it opened 23 new positions, sold out of 18, added to 24 and reduced 14. The biggest buy was a new position in Rezolute (RZLT) and the biggest sale an exit from Merus (MRUS).

Most Recent 13F
Q2 2026
Location
New York, NY
CIK
0002005245
Portfolio Value
$2.6B (Q3 2025)
SEC Filing
0002005245-25-000012 ↗ filed Nov 13, 2025

Holdings Value

0$1.0B$2.0B$3.0B$4.0B$5.0B Q3 2024: $2.0B Q3 2024 Q4 2024: $2.3B Q4 2024 Q1 2025: $1.8B Q1 2025 Q2 2025: $1.9B Q2 2025 Q3 2025: $2.6B $2.6B Q3 2025 Q4 2025: $3.4B Q4 2025 Q1 2026: $3.6B Q1 2026 Q2 2026: $4.9B Q2 2026

Holdings 115 stocks · $2.6B
SRRK Scholar Rock Holding Corp. 13.48% 9,250,005 $344.5M No change
KYMR Kymera Therapeutics Inc. 7.59% 3,428,150 $194.0M No change
ONC Beone Medicines Ltd.-ADR 6.57% 492,990 $168.0M Reduce -3.3%
ARWR Arrowhead Pharmaceuticals Inc. 3.60% 2,669,880 $92.1M No change
BCAX Bicara Therapeutics Inc. 3.22% 5,216,969 $82.4M No change
CNTA Centessa Pharmaceuticals Ltd. 3.06% 3,227,517 $78.3M Reduce -6.7%
CRNX Crinetics Pharmaceuticals Inc. 2.75% 1,688,611 $70.3M No change
EWTX Edgewise Therapeutics Inc. 2.47% 3,897,099 $63.2M Add +23.3%
IRON Disc Medicine Inc. 2.36% 913,401 $60.4M Reduce -16.9%
DYN Dyne Therapeutics Inc. 2.34% 4,729,174 $59.8M Reduce -2.2%
APLS Apellis Pharmaceuticals Inc. 2.28% 2,578,396 $58.3M No change
RNAM Avidity Biosciences Inc. 2.19% 1,285,610 $56.0M Add +15.8%
STOK Stoke Therapeutics Inc. 2.07% 2,247,347 $52.8M No change
LXRX Lexicon Pharmaceuticals Inc. 2.06% 38,918,903 $52.5M No change
RYTM Rhythm Pharmaceuticals Inc. 1.98% 499,975 $50.5M Add +22.0%
TNGX Tango Therapeutics Inc. 1.93% 5,883,188 $49.4M Add +74.8%
RVMD Revolution Medicines Inc. 1.91% 1,043,720 $48.7M Add +11.2%
ASND Ascendis Pharma A/S 1.83% 235,862 $46.9M Reduce -4.1%
RZLT Rezolute Inc. 1.79% 4,870,000 $45.8M New
SLDB Solid Biosciences Inc. 1.79% 7,415,905 $45.8M No change
SEPN Septerna Inc. 1.62% 2,202,514 $41.4M No change
RCUS Arcus Biosciences Inc. 1.55% 2,912,077 $39.6M Add +80.6%
TSHA Taysha Gene Therapies Inc. 1.41% 11,014,737 $36.0M No change
TBLA Taboola.com Ltd. 1.33% 9,969,495 $34.0M No change
XENE Xenon Pharmaceuticals Inc. 1.28% 812,761 $32.6M No change
SLNO Soleno Therapeutics Inc. 1.24% 467,342 $31.6M No change
RAPP Rapport Therapeutics Inc. 1.22% 1,053,469 $31.3M Add +178.3%
GPCR Structure Therapeutics Inc. 1.12% 1,026,811 $28.8M New
WVE Wave Life Sciences Ltd. 1.06% 3,696,322 $27.1M No change
RELY Remitly Global Inc. 1.03% 1,618,271 $26.4M Add +213.9%
COGT Cogent Biosciences Inc. 0.97% 1,724,279 $24.8M Add +101.8%
TRVI Trevi Therapeutics Inc. 0.91% 2,536,867 $23.2M Reduce -35.6%
NAMS Newamsterdam Pharma Co. NV 0.85% 765,705 $21.8M Reduce -35.9%
KRRO Korro Bio Inc. 0.78% 418,833 $20.1M No change
ERAS Erasca Inc. 0.75% 8,757,249 $19.1M No change
IHS Ihs Holding Ltd. 0.63% 2,357,520 $16.1M No change
QURE Uniqure NV 0.63% 275,200 $16.1M New
BCYC Bicycle Therapeutics PLC-ADR 0.61% 2,012,752 $15.6M No change
SLN Silence Therapeutics PLC-ADR 0.59% 2,911,438 $15.1M No change
RAPT Rapt Therapeutics Inc. 0.59% 580,466 $15.0M New
UPB Upstream Bio Inc. 0.58% 788,450 $14.8M No change
GOSS Gossamer Bio Inc. 0.54% 5,208,968 $13.7M No change
AVBP Arrivent Biopharma Inc. 0.51% 700,000 $12.9M No change
AMZN Amazon.com Inc. 0.50% 58,500 $12.8M Add +3.5%
ORIC Oric Pharmaceuticals Inc. 0.47% 1,007,575 $12.1M No change
DNLI Denali Therapeutics Inc. 0.47% 821,513 $11.9M No change
IONQ Ionq Inc. 0.41% 170,000 $10.5M No change
SION Sionna Therapeutics Inc. 0.37% 325,000 $9.6M No change
CRWD CrowdStrike Holdings Inc. Class A 0.35% 18,500 $9.1M No change
MSFT Microsoft Corp. 0.35% 17,150 $8.9M Add +6.2%
SEER Seer Inc. 0.34% 4,000,000 $8.7M No change
NBIS Nebius Group NV 0.32% 72,600 $8.2M Add +42.4%
NMRA Neumora Therapeutics Inc. 0.31% 4,358,283 $7.9M No change
TSM Taiwan Semiconductor-SP ADR 0.31% 28,200 $7.9M Reduce -7.5%
CRM Salesforce Inc. 0.28% 30,100 $7.1M Add +33.2%
CGEM Cullinan Therapeutics Inc. 0.28% 1,193,410 $7.1M No change
NVDA Nvidia Corp. 0.27% 37,485 $7.0M Reduce -25.0%
NOW ServiceNow Inc. 0.26% 7,126 $6.6M Add +39.0%
SYRE Spyre Therapeutics Inc. 0.24% 368,598 $6.2M No change
RNAC Cartesian Therapeutics Inc. 0.23% 563,272 $5.8M No change
PDD PDD Holdings Inc. 0.22% 43,401 $5.7M Reduce -18.0%
ELDN Eledon Pharmaceuticals Inc. 0.21% 2,072,767 $5.4M Add +200.3%
ADBE Adobe Inc. 0.21% 15,051 $5.3M No change
GOOGL Alphabet Inc. Class A 0.20% 21,203 $5.2M Reduce -58.2%
FROG Jfrog Ltd. 0.20% 107,116 $5.1M No change
SGMT Sagimet Biosciences Inc. Class A 0.19% 724,771 $5.0M No change
DT Dynatrace Inc. 0.19% 100,229 $4.9M Add +33.2%
DDOG Datadog Inc. Class A 0.18% 32,925 $4.7M Reduce -14.3%
NBP Novabridge Biosciences filed as I MAB 0.17% 1,165,957 $4.4M New
AGEN Agenus Inc. 0.16% 1,064,250 $4.1M No change
LXEO Lexeo Therapeutics Inc. 0.16% 603,435 $4.0M No change
BDTX Black Diamond Therapeutics I 0.16% 1,046,517 $4.0M No change
WHWK Whitehawk Therapeutics Inc. 0.15% 2,082,000 $4.0M No change
VTVT VTV Therapeutics Inc. Class A 0.15% 163,000 $3.8M New
TIL Instil Bio Inc. 0.14% 203,933 $3.6M No change
FHTX Foghorn Therapeutics Inc. 0.14% 720,720 $3.5M No change
PRQR Proqr Therapeutics NV 0.13% 1,552,183 $3.3M No change
EDU New Oriental Educatio-SP ADR 0.13% 62,000 $3.3M Reduce -13.9%
CRWV Coreweave Inc. Class A 0.13% 24,000 $3.3M New
PEPG Pepgen Inc. 0.13% 700,000 $3.2M New
GTLB Gitlab Inc. Class A 0.11% 64,000 $2.9M Add +82.9%
BEKE Ke Holdings Inc.-ADR filed as KE HLDGS INC 0.11% 145,000 $2.8M Add +38.1%
PANW Palo Alto Networks Inc. 0.11% 13,450 $2.7M Add +17.0%
TENX Tenax Therapeutics Inc. 0.10% 352,441 $2.7M New
WK Workiva Inc. 0.10% 30,000 $2.6M Add +7.1%
QCOM Qualcomm Inc. 0.09% 14,000 $2.3M No change
BIOA Bioage Labs Inc. 0.09% 382,406 $2.2M No change
KDP Keurig Dr Pepper Inc. 0.08% 77,050 $2.0M New
HUBS HubSpot Inc. 0.07% 4,000 $1.9M Add +33.3%
CMG Chipotle Mexican Grill Inc. 0.07% 47,500 $1.9M New
KLRS Kalaris Therapeutics Inc. 0.07% 318,264 $1.8M Add +12.6%
GBIO Generation Bio Co. 0.07% 296,892 $1.8M No change
CLBT Cellebrite Di Ltd. 0.07% 90,000 $1.7M Add +50.0%
PRMB Primo Brands Corp. 0.06% 75,000 $1.7M Add +100.0%
SPOT Spotify Technology SA 0.06% 2,173 $1.5M New
NIQ Niq Global Intelligence PLC 0.06% 95,000 $1.5M New
MNDY Monday.com Ltd. 0.05% 7,000 $1.4M New
SAIL Sailpoint Inc. 0.04% 50,000 $1.1M No change
ESTC Elastic NV 0.04% 12,500 $1.1M New
IREN Iren Ltd. filed as IREN LIMITED 0.04% 20,000 $938K New
SEMR Semrush Holdings Inc. Class A 0.03% 125,000 $885K No change
AS Amer Sports Inc. 0.03% 25,000 $869K New
PINS Pinterest Inc. Class A 0.03% 25,000 $804K New
FIG Figma Inc. Class A 0.03% 15,000 $778K New
CFLT Confluent Inc. Class A 0.03% 37,500 $743K New
PCOR Procore Technologies Inc. 0.03% 10,000 $729K No change
ALAB Astera Labs Inc. 0.03% 3,500 $685K New
TSLA Tesla Inc. 0.03% 1,500 $667K Reduce -62.5%
CHYM Chime Financial Inc. Class A 0.02% 25,000 $504K New
CCC CCC Intelligent Solutions Ho 0.02% 50,000 $456K No change
KVUE Kenvue Inc. 0.02% 25,000 $406K New
VRT Vertiv Holdings Co. Class A 0.01% 2,000 $302K No change
CYCLERION THERAPEUTICS INC 0.01% 116,155 $267K No change
CRBU Caribou Biosciences Inc. 0.01% 105,347 $245K No change
IRWD Ironwood Pharmaceuticals Inc. 0.01% 110,532 $145K No change

Portfolio Sells Q2 2025 → Q3 2025
MRUS Merus NV Sold out 0.00% −2.32
APGE Apogee Therapeutics Inc. Sold out 0.00% −1.34
MLTX Moonlake Immunotherapeutics Sold out 0.00% −1.24
AKRO Akero Therapeutics Inc. Sold out 0.00% −0.88
IRON Disc Medicine Inc. Reduce -16.9% 2.36% −0.65
PCVX Vaxcyte Inc. Sold out 0.00% −0.50
ASND Ascendis Pharma A/S Reduce -4.1% 1.83% −0.36
VERA Vera Therapeutics Inc. Sold out 0.00% −0.30
PCRX Pacira Biosciences Inc. Sold out 0.00% −0.28
NAMS Newamsterdam Pharma Co. NV Reduce -35.9% 0.85% −0.27
GOOGL Alphabet Inc. Class A Reduce -58.2% 0.20% −0.26
TRVI Trevi Therapeutics Inc. Reduce -35.6% 0.91% −0.21
IGMS Igm Biosciences Inc. Sold out 0.00% −0.19
VIGL Vigil Neuroscience Inc. Sold out 0.00% −0.17
NVDA Nvidia Corp. Reduce -25.0% 0.27% −0.14
DDOG Datadog Inc. Class A Reduce -14.3% 0.18% −0.08
UNH Unitedhealth Group Inc. Sold out 0.00% −0.08
TRML Tourmaline Bio Inc. Sold out 0.00% −0.08
RCKT Rocket Pharmaceuticals Inc. Sold out 0.00% −0.07
EDU New Oriental Educatio-SP ADR Reduce -13.9% 0.13% −0.07
BIRK Birkenstock Holding PLC Sold out 0.00% −0.06
PDD PDD Holdings Inc. Reduce -18.0% 0.22% −0.06
TSM Taiwan Semiconductor-SP ADR Reduce -7.5% 0.31% −0.05
DYN Dyne Therapeutics Inc. Reduce -2.2% 2.34% −0.04
TSLA Tesla Inc. Reduce -62.5% 0.03% −0.04
TEAM Atlassian Corp. Class A Sold out 0.00% −0.04
HOOK Hookipa Pharma Inc. Sold out 0.00% −0.04
PCG P G & E Corp. Sold out 0.00% −0.02
RDDT Reddit Inc. Class A Sold out 0.00% −0.02
DECK Deckers Outdoor Corp. Sold out 0.00% −0.01
ONC Beone Medicines Ltd.-ADR Reduce -3.3% 6.57% +0.18
CNTA Centessa Pharmaceuticals Ltd. Reduce -6.7% 3.06% +0.71

Portfolio Buys Q2 2025 → Q3 2025
RZLT Rezolute Inc. New 1.79% +1.79
GPCR Structure Therapeutics Inc. New 1.12% +1.12
TNGX Tango Therapeutics Inc. Add +74.8% 1.93% +1.04
RAPP Rapport Therapeutics Inc. Add +178.3% 1.22% +1.00
RCUS Arcus Biosciences Inc. Add +80.6% 1.55% +0.87
COGT Cogent Biosciences Inc. Add +101.8% 0.97% +0.65
RYTM Rhythm Pharmaceuticals Inc. Add +22.0% 1.98% +0.64
QURE Uniqure NV New 0.63% +0.63
RAPT Rapt Therapeutics Inc. New 0.59% +0.59
RNAM Avidity Biosciences Inc. Add +15.8% 2.19% +0.56
RELY Remitly Global Inc. Add +213.9% 1.03% +0.53
EWTX Edgewise Therapeutics Inc. Add +23.3% 2.47% +0.33
NBIS Nebius Group NV Add +42.4% 0.32% +0.17
NBP Novabridge Biosciences New 0.17% +0.17
VTVT VTV Therapeutics Inc. Class A New 0.15% +0.15
CRWV Coreweave Inc. Class A New 0.13% +0.13
PEPG Pepgen Inc. New 0.13% +0.13
RVMD Revolution Medicines Inc. Add +11.2% 1.91% +0.12
ELDN Eledon Pharmaceuticals Inc. Add +200.3% 0.21% +0.11
TENX Tenax Therapeutics Inc. New 0.10% +0.10
KDP Keurig Dr Pepper Inc. New 0.08% +0.08
CMG Chipotle Mexican Grill Inc. New 0.07% +0.07
SPOT Spotify Technology SA New 0.06% +0.06
NIQ Niq Global Intelligence PLC New 0.06% +0.06
MNDY Monday.com Ltd. New 0.05% +0.05
ESTC Elastic NV New 0.04% +0.04
IREN Iren Ltd. New 0.04% +0.04
AS Amer Sports Inc. New 0.03% +0.03
KLRS Kalaris Therapeutics Inc. Add +12.6% 0.07% +0.03
PINS Pinterest Inc. Class A New 0.03% +0.03
GTLB Gitlab Inc. Class A Add +82.9% 0.11% +0.03
FIG Figma Inc. Class A New 0.03% +0.03
CFLT Confluent Inc. Class A New 0.03% +0.03
ALAB Astera Labs Inc. New 0.03% +0.03
CHYM Chime Financial Inc. Class A New 0.02% +0.02
KVUE Kenvue Inc. New 0.02% +0.02
CLBT Cellebrite Di Ltd. Add +50.0% 0.07% +0.02
BEKE Ke Holdings Inc.-ADR Add +38.1% 0.11% +0.01
PRMB Primo Brands Corp. Add +100.0% 0.06% +0.01
WK Workiva Inc. Add +7.1% 0.10% +0.00
HUBS HubSpot Inc. Add +33.3% 0.07% −0.01
PANW Palo Alto Networks Inc. Add +17.0% 0.11% −0.01
NOW ServiceNow Inc. Add +39.0% 0.26% −0.02
DT Dynatrace Inc. Add +33.2% 0.19% −0.03
CRM Salesforce Inc. Add +33.2% 0.28% −0.04
MSFT Microsoft Corp. Add +6.2% 0.35% −0.07
AMZN Amazon.com Inc. Add +3.5% 0.50% −0.14

All Filings

QuarterPositions13F Reported ValueTop Holdings
Q2 2026 115$4.9BSRRK, KYMR, ERAS, MANE, TNGX
Q1 2026 100$3.6BSRRK, KYMR, ERAS, EWTX, ONC
Q4 2025 113$3.4BSRRK, KYMR, ONC, EWTX, RVMD
Q3 2025 115$2.6BSRRK, KYMR, ONC, ARWR, BCAX
Q2 2025 110$1.9BSRRK, KYMR, ONC, IRON, CRNX
Q1 2025Amended 116$1.8BSRRK, ONC, KYMR, BPMC, CRNX
Q4 2024 117$2.3BSRRK, ONC, KYMR, APLS, CRNX
Q3 2024 109$2.0BKYMR, ONC, SRRK, BCAX, ARGX