Siren, L.L.C.

In its 13F for Q4 2024 (holdings as of December 31, 2024, filed February 14, 2025), Siren, L.L.C. reported 117 stock positions worth $2.3 billion. Its top holding was Scholar Rock (SRRK) at 17.7% of the portfolio, followed by Beone Medicines Ltd.-ADR (ONC, 5.3%) and Kymera Therapeutics (KYMR, 5.3%). Compared with Q3 2024, it opened 22 new positions, sold out of 14, added to 21 and reduced 22. The biggest buy was a new position in Septerna (SEPN) and the biggest sale Avidity Biosciences (RNAM, shares −22%).

Most Recent 13F
Q2 2026
Location
New York, NY
CIK
0002005245
Portfolio Value
$2.3B (Q4 2024)
SEC Filing
0002005245-25-000002 ↗ filed Feb 14, 2025

Holdings Value

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

Holdings 117 stocks · $2.3B
SRRK Scholar Rock Holding Corp. 17.66% 9,250,005 $399.8M Reduce -17.9%
ONC Beone Medicines Ltd.-ADR filed as BEIGENE LTD 5.34% 653,721 $120.7M Add +16.1%
KYMR Kymera Therapeutics Inc. 5.28% 2,969,733 $119.5M No change
APLS Apellis Pharmaceuticals Inc. 3.97% 2,816,258 $89.9M Add +29.9%
CRNX Crinetics Pharmaceuticals Inc. 3.64% 1,609,652 $82.3M Add +22.9%
ARGX Argenx SE - ADR 3.13% 115,045 $70.8M Reduce -19.9%
BCAX Bicara Therapeutics Inc. 2.52% 3,272,827 $57.0M Add +6.5%
ARWR Arrowhead Pharmaceuticals Inc. 2.41% 2,901,681 $54.6M Add +18.0%
NAMS Newamsterdam Pharma Co. NV 2.38% 2,095,638 $53.9M Add +127.7%
SEPN Septerna Inc. 2.23% 2,202,514 $50.4M New
CNTA Centessa Pharmaceuticals Ltd. 2.22% 3,004,677 $50.3M Reduce -7.8%
SWTX Springworks Therapeutics Inc. 2.20% 1,377,701 $49.8M No change
NMRA Neumora Therapeutics Inc. 2.06% 4,396,100 $46.6M Add +68.7%
WVE Wave Life Sciences Ltd. 2.05% 3,750,491 $46.4M Reduce -34.5%
ASND Ascendis Pharma A/S 1.81% 297,321 $40.9M Reduce -14.5%
MDGL Madrigal Pharmaceuticals Inc. 1.72% 125,942 $38.9M New
TBLA Taboola.com Ltd. 1.61% 9,969,495 $36.4M No change
APGE Apogee Therapeutics Inc. 1.50% 747,325 $33.9M New
MRUS Merus NV 1.46% 784,412 $33.0M Add +15.0%
RNAM Avidity Biosciences Inc. 1.45% 1,127,295 $32.8M Reduce -21.8%
VERA Vera Therapeutics Inc. 1.42% 758,465 $32.1M Reduce -9.5%
DYN Dyne Therapeutics Inc. 1.40% 1,347,456 $31.7M Add +18.8%
XENE Xenon Pharmaceuticals Inc. 1.29% 743,769 $29.2M No change
LXRX Lexicon Pharmaceuticals Inc. 1.27% 38,918,903 $28.8M No change
BCYC Bicycle Therapeutics PLC-ADR 1.14% 1,839,398 $25.8M New
RVMD Revolution Medicines Inc. 1.10% 571,548 $25.0M Reduce -24.2%
PCVX Vaxcyte Inc. 1.08% 299,991 $24.6M No change
RCUS Arcus Biosciences Inc. 1.06% 1,612,077 $24.0M No change
ERAS Erasca Inc. 0.98% 8,857,179 $22.2M No change
STOK Stoke Therapeutics Inc. 0.97% 2,000,000 $22.1M New
IGMS Igm Biosciences Inc. 0.90% 3,330,422 $20.3M No change
EWTX Edgewise Therapeutics Inc. 0.87% 734,343 $19.6M Add +81.7%
SLN Silence Therapeutics PLC-ADR 0.86% 2,831,770 $19.5M No change
CYTK Cytokinetics Inc. 0.84% 402,323 $18.9M Reduce -23.5%
DNLI Denali Therapeutics Inc. 0.75% 834,028 $17.0M No change
KRRO Korro Bio Inc. 0.70% 418,833 $15.9M No change
SLNO Soleno Therapeutics Inc. 0.70% 351,818 $15.8M New
PRTA Prothena Corp. PLC 0.67% 1,099,840 $15.2M No change
SLDB Solid Biosciences Inc. 0.66% 3,749,041 $15.0M Add +36.4%
CGEM Cullinan Therapeutics Inc. 0.65% 1,211,357 $14.8M No change
UPB Upstream Bio Inc. 0.58% 800,000 $13.2M New
TRVI Trevi Therapeutics Inc. 0.53% 2,906,060 $12.0M New
KURA Kura Oncology Inc. 0.52% 1,339,942 $11.7M No change
TSHA Taysha Gene Therapies Inc. 0.50% 6,602,475 $11.4M Add +35.3%
RELY Remitly Global Inc. 0.49% 490,449 $11.1M Add +1861.8%
RNAC Cartesian Therapeutics Inc. 0.45% 572,236 $10.2M No change
MSFT Microsoft Corp. 0.43% 23,000 $9.7M Add +4.5%
JANX Janux Therapeutics Inc. 0.41% 175,000 $9.4M New
SEER Seer Inc. 0.41% 4,000,000 $9.2M No change
IONS Ionis Pharmaceuticals Inc. 0.39% 250,000 $8.7M No change
SYRE Spyre Therapeutics Inc. 0.38% 374,000 $8.7M New
CRWD CrowdStrike Holdings Inc. Class A 0.36% 24,000 $8.2M Reduce -4.0%
IOVA Iovance Biotherapeutics Inc. 0.36% 1,106,040 $8.2M No change
ORIC Oric Pharmaceuticals Inc. 0.36% 1,007,575 $8.1M No change
TNGX Tango Therapeutics Inc. 0.36% 2,603,897 $8.0M No change
AMZN Amazon.com Inc. 0.35% 36,500 $8.0M Add +5.0%
RCKT Rocket Pharmaceuticals Inc. 0.33% 600,000 $7.5M New
IONQ Ionq Inc. 0.31% 170,000 $7.1M Reduce -66.0%
IHS Ihs Holding Ltd. 0.30% 2,357,520 $6.9M No change
RAPP Rapport Therapeutics Inc. 0.30% 384,197 $6.8M No change
NVDA Nvidia Corp. 0.29% 48,932 $6.6M No change
NOW ServiceNow Inc. 0.26% 5,605 $5.9M Reduce -25.3%
SLRN Acelyrin Inc. 0.24% 1,729,665 $5.4M No change
PDD PDD Holdings Inc. 0.23% 52,901 $5.1M Add +30.9%
GOSS Gossamer Bio Inc. 0.21% 5,208,968 $4.7M Reduce -60.8%
DT Dynatrace Inc. 0.20% 82,729 $4.5M No change
BA The Boeing Co. 0.20% 25,000 $4.4M New
EDU New Oriental Educatio-SP ADR 0.19% 68,500 $4.4M Add +77.9%
DDOG Datadog Inc. Class A 0.19% 30,425 $4.3M Reduce -7.6%
PRQR Proqr Therapeutics NV 0.18% 1,575,000 $4.2M New
LXEO Lexeo Therapeutics Inc. 0.18% 603,435 $4.0M No change
ADBE Adobe Inc. 0.17% 8,798 $3.9M Add +779.8%
PHAT Phathom Pharmaceuticals Inc. 0.17% 460,753 $3.7M No change
TIL Instil Bio Inc. 0.16% 192,433 $3.7M No change
FROG Jfrog Ltd. 0.16% 120,116 $3.5M Add +96.9%
FHTX Foghorn Therapeutics Inc. 0.15% 720,720 $3.4M No change
VIGL Vigil Neuroscience Inc. 0.15% 1,991,038 $3.4M No change
NBIS Nebius Group NV 0.15% 120,000 $3.3M New
SGMT Sagimet Biosciences Inc. Class A 0.14% 724,771 $3.3M No change
GBIO Generation Bio Co. 0.14% 2,982,733 $3.2M No change
TSM Taiwan Semiconductor-SP ADR 0.13% 15,000 $3.0M Reduce -40.0%
FCX Freeport-McMoran Inc. 0.13% 75,000 $2.9M New
ALLOVIR INC 0.12% 6,597,167 $2.8M No change
OVID Ovid Therapeutics Inc. 0.12% 2,850,000 $2.7M No change
SE Sea Ltd.-ADR 0.12% 25,000 $2.7M Reduce -33.3%
ESTC Elastic NV 0.11% 25,000 $2.5M Add +92.3%
QCOM Qualcomm Inc. 0.10% 15,000 $2.3M No change
BIOA Bioage Labs Inc. 0.10% 388,000 $2.2M Add +29.3%
BDTX Black Diamond Therapeutics I 0.10% 1,046,517 $2.2M No change
RGNX Regenxbio Inc. 0.10% 284,000 $2.2M No change
TRML Tourmaline Bio Inc. 0.08% 91,426 $1.9M No change
PCOR Procore Technologies Inc. 0.07% 20,000 $1.5M Reduce -38.1%
APLT Applied Therapeutics Inc. 0.06% 1,633,768 $1.4M No change
GOOGL Alphabet Inc. Class A 0.06% 7,000 $1.3M Reduce -36.4%
PYPL PayPal Holdings Inc. 0.06% 15,000 $1.3M No change
HOOK Hookipa Pharma Inc. 0.05% 566,640 $1.1M No change
HCA HCA Healthcare Inc. 0.05% 3,750 $1.1M New
BEKE Ke Holdings Inc.-ADR filed as KE HLDGS INC 0.05% 60,000 $1.1M Reduce -40.0%
WK Workiva Inc. 0.05% 10,000 $1.1M New
PANW Palo Alto Networks Inc. 0.05% 6,000 $1.1M Reduce -33.3%

Show all 117 holdings

Options reported separately and not counted above: GOSS calls ($187K).

Portfolio Sells Q3 2024 → Q4 2024
RNAM Avidity Biosciences Inc. Reduce -21.8% 1.45% −1.86
LBPH Longboard Pharmaceuticals Inc. Sold out 0.00% −1.51
ASND Ascendis Pharma A/S Reduce -14.5% 1.81% −0.79
ARGX Argenx SE - ADR Reduce -19.9% 3.13% −0.77
BHVN Biohaven Ltd. Sold out 0.00% −0.71
RVMD Revolution Medicines Inc. Reduce -24.2% 1.10% −0.61
CYTK Cytokinetics Inc. Reduce -23.5% 0.84% −0.55
GOSS Gossamer Bio Inc. Reduce -60.8% 0.21% −0.45
VERA Vera Therapeutics Inc. Reduce -9.5% 1.42% −0.44
CNTA Centessa Pharmaceuticals Ltd. Reduce -7.8% 2.22% −0.38
NGNE Neurogene Inc. Sold out 0.00% −0.37
WVE Wave Life Sciences Ltd. Reduce -34.5% 2.05% −0.30
SYRS Syros Pharmaceuticals Inc. Sold out 0.00% −0.28
NVCR Novocure Ltd. Sold out 0.00% −0.27
ANRO Alto Neuroscience Inc. Sold out 0.00% −0.22
AGEN Agenus Inc. Sold out 0.00% −0.21
ADCT Adc Therapeutics SA Sold out 0.00% −0.18
GRITSTONE BIO INC Sold out 0.00% −0.10
V Visa Inc. Class A Sold out 0.00% −0.10
TSM Taiwan Semiconductor-SP ADR Reduce -40.0% 0.13% −0.09
NTRA Natera Inc. Sold out 0.00% −0.08
NOW ServiceNow Inc. Reduce -25.3% 0.26% −0.07
SE Sea Ltd.-ADR Reduce -33.3% 0.12% −0.06
OXY Occidental Petroleum Corp. Reduce -57.1% 0.03% −0.06
BEKE Ke Holdings Inc.-ADR Reduce -40.0% 0.05% −0.05
TERN Terns Pharmaceuticals Inc. Sold out 0.00% −0.04
RBRK Rubrik Inc. Class A Sold out 0.00% −0.04
PCOR Procore Technologies Inc. Reduce -38.1% 0.07% −0.03
GOOGL Alphabet Inc. Class A Reduce -36.4% 0.06% −0.03
PANW Palo Alto Networks Inc. Reduce -33.3% 0.05% −0.03
META Meta Platforms Inc. Class A Reduce -33.3% 0.03% −0.02
GLYCOMIMETICS INC Sold out 0.00% −0.02
DDOG Datadog Inc. Class A Reduce -7.6% 0.19% +0.00
CRWD CrowdStrike Holdings Inc. Class A Reduce -4.0% 0.36% +0.01
IONQ Ionq Inc. Reduce -66.0% 0.31% +0.10
SRRK Scholar Rock Holding Corp. Reduce -17.9% 17.66% +13.15

Portfolio Buys Q3 2024 → Q4 2024
SEPN Septerna Inc. New 2.23% +2.23
MDGL Madrigal Pharmaceuticals Inc. New 1.72% +1.72
NAMS Newamsterdam Pharma Co. NV Add +127.7% 2.38% +1.61
APGE Apogee Therapeutics Inc. New 1.50% +1.50
BCYC Bicycle Therapeutics PLC-ADR New 1.14% +1.14
STOK Stoke Therapeutics Inc. New 0.97% +0.97
APLS Apellis Pharmaceuticals Inc. Add +29.9% 3.97% +0.84
SLNO Soleno Therapeutics Inc. New 0.70% +0.70
UPB Upstream Bio Inc. New 0.58% +0.58
TRVI Trevi Therapeutics Inc. New 0.53% +0.53
RELY Remitly Global Inc. Add +1861.8% 0.49% +0.47
JANX Janux Therapeutics Inc. New 0.41% +0.41
SYRE Spyre Therapeutics Inc. New 0.38% +0.38
NMRA Neumora Therapeutics Inc. Add +68.7% 2.06% +0.34
RCKT Rocket Pharmaceuticals Inc. New 0.33% +0.33
EWTX Edgewise Therapeutics Inc. Add +81.7% 0.87% +0.33
CRNX Crinetics Pharmaceuticals Inc. Add +22.9% 3.64% +0.29
BA The Boeing Co. New 0.20% +0.20
PRQR Proqr Therapeutics NV New 0.18% +0.18
ADBE Adobe Inc. Add +779.8% 0.17% +0.15
NBIS Nebius Group NV New 0.15% +0.15
FCX Freeport-McMoran Inc. New 0.13% +0.13
FROG Jfrog Ltd. Add +96.9% 0.16% +0.07
ESTC Elastic NV Add +92.3% 0.11% +0.06
HCA HCA Healthcare Inc. New 0.05% +0.05
WK Workiva Inc. New 0.05% +0.05
EDU New Oriental Educatio-SP ADR Add +77.9% 0.19% +0.05
BASE Couchbase Inc. New 0.04% +0.04
RACE Ferrari NV New 0.04% +0.04
AMZN Amazon.com Inc. Add +5.0% 0.35% +0.03
ARWR Arrowhead Pharmaceuticals Inc. Add +18.0% 2.41% +0.03
MRVL Marvell Technology Inc. New 0.02% +0.02
MNDY Monday.com Ltd. New 0.02% +0.02
SEMR Semrush Holdings Inc. Class A New 0.02% +0.02
TSHA Taysha Gene Therapies Inc. Add +35.3% 0.50% +0.01
MSFT Microsoft Corp. Add +4.5% 0.43% −0.05
PDD PDD Holdings Inc. Add +30.9% 0.23% −0.05
BIOA Bioage Labs Inc. Add +29.3% 0.10% −0.21
MRUS Merus NV Add +15.0% 1.46% −0.25
SLDB Solid Biosciences Inc. Add +36.4% 0.66% −0.30
DYN Dyne Therapeutics Inc. Add +18.8% 1.40% −0.64
ONC Beone Medicines Ltd.-ADR Add +16.1% 5.34% −0.99
BCAX Bicara Therapeutics Inc. Add +6.5% 2.52% −1.40

Options Activity Q3 2024 → Q4 2024
PYPL PayPal Holdings Inc. call Sold out 26,000 $2.0Mbefore exit
PERCEPTION CAPITAL CORP III call Sold out 126,666 $4Kbefore exit

Calls and puts are listed by the shares they cover; their value is not part of the stock holdings above.

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