Siren, L.L.C.

Name: Siren, L.L.C. 13F holdings, Q1 2025
Creator: Siren, L.L.C.
Published: 2025-05-23

Q2 2026Q1 2026Q4 2025Q3 2025Q2 2025Q4 2024Q3 2024

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
INTC Intel Corp.	0.05%	40,000	$908K	No change
INFA Informatica Inc. Class A	0.05%	50,000	$873K	New
BA The Boeing Co.	0.05%	5,000	$853K	Reduce -80.0%
BASE Couchbase Inc.	0.04%	49,850	$785K	Reduce -16.9%
AGEN Agenus Inc.	0.04%	500,000	$753K	New
KRON Kronos Bio Inc.	0.04%	842,954	$695K	No change
PCOR Procore Technologies Inc.	0.04%	10,000	$660K	Reduce -50.0%
RACE Ferrari NV	0.04%	1,500	$636K	Reduce -25.0%
HOOK Hookipa Pharma Inc.	0.03%	566,640	$612K	No change
DECK Deckers Outdoor Corp.	0.03%	5,000	$559K	New
USB US Bancorp	0.03%	12,500	$528K	New
OXY Occidental Petroleum Corp.	0.03%	10,000	$494K	Reduce -33.3%
GDS GDS Holdings Ltd. - ADR filed as GDS HLDGS LTD	0.02%	12,500	$317K	New
CYCLERION THERAPEUTICS INC	0.02%	116,155	$290K	No change
IRWD Ironwood Pharmaceuticals Inc.	0.01%	110,532	$162K	No change
CRBU Caribou Biosciences Inc.	0.01%	105,347	$96K	No change

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