Siren, L.L.C.
New York, NY
$4.9bn in 115 US stocks at the end of 30 June 2026. The top 10 are 44.8% of the money. It changed about 19.7% of the portfolio this quarter.
Value
$4.9bn
Stocks
115
Top 10 share
44.8%
Turnover
19.7%
What changed this quarter
New
Bought for the first time this quarter.
- Parabilis MedicinesPBLS1.7% of the fund
- Abivax SAABVX1.6% of the fund
- Hemab Therapeutics HoldingsCOAG1.6% of the fund
- Relay TherapeuticsRLAY1.4% of the fund
- Kailera TherapeuticsKLRA1.0% of the fund
- Capital One FinancialCOF0.7% of the fund
- Oruka TherapeuticsORKA0.5% of the fund
- Seaport TherapeuticsSPTX0.5% of the fund
- Tyra BiosciencesTYRA0.5% of the fund
- AdageneADAG0.2% of the fund
- enGene TherapeuticsENGN0.2% of the fund
- Oculis Holding AGOCS0.2% of the fund
- Design TherapeuticsDSGN0.2% of the fund
- Eloxx PharmaceuticalsELOX0.1% of the fund
- Alibaba Group HldgBABA<0.1% of the fund
- OusterOUST<0.1% of the fund
- Palisade BIOPALI<0.1% of the fund
- Odyssey TherapeuticsODTX<0.1% of the fund
- ZoetisZTS<0.1% of the fund
- NetflixNFLX<0.1% of the fund
- QuantinuumQNT<0.1% of the fund
- Entera BioENTX<0.1% of the fund
- Lumentum HoldingsLITE<0.1% of the fund
- FoxFOXA<0.1% of the fund
- AT&TT<0.1% of the fund
Added
Bought more of a stock they already held.
- VeradermicsMANE4.1% of the fund+10%
- Tango TherapeuticsTNGX3.9% of the fund+9%
- Arrowhead PharmaceuticalsARWR2.8% of the fund+6%
- Rhythm PharmaceuticalsRYTM2.6% of the fund+57%
- Enliven TherapeuticsELVN1.8% of the fund+138%
- Spyre TherapeuticsSYRE1.7% of the fund+18%
- Cogent BiosciencesCOGT1.5% of the fund+9%
- Taysha Gene TherapiesTSHA1.4% of the fund+12%
- Definium TherapeuticsDFTX1.4% of the fund+54%
- CytokineticsCYTK1.3% of the fund+24%
- Olema PharmaceuticalsOLMA1.2% of the fund+2%
- Silence TherapeuticsSLN0.7% of the fund+14%
- Cullinan TherapeuticsCGEM0.7% of the fund+59%
- AlphabetGOOGL0.7% of the fund+37%
- AbsciABSI0.6% of the fund+37%
- Sionna TherapeuticsSION0.5% of the fund+104%
- Amylyx PharmaceuticalsAMLX0.5% of the fund+20%
- AnnexonANNX0.5% of the fund+13%
- Taiwan Semiconductor ManufacturingTSM0.4% of the fund+6%
- NvidiaNVDA0.4% of the fund+7%
- Whitehawk TherapeuticsWHWK0.2% of the fund+12%
- ServiceNowNOW0.2% of the fund+15%
- BroadcomAVGO0.2% of the fund+67%
- IrenIREN0.2% of the fund+306%
- PDD HoldingsPDD0.1% of the fund+14%
Cut
Sold some of their stake.
- Scholar Rock HoldingSRRK10.7% of the fund-12%
- Kymera TherapeuticsKYMR6.8% of the fund-8%
- Revolution MedicinesRVMD3.4% of the fund-19%
- Bicara TherapeuticsBCAX3.4% of the fund-3%
- Edgewise TherapeuticsEWTX2.6% of the fund-28%
- Arcus BiosciencesRCUS1.5% of the fund-20%
- Disc MedicineIRON1.3% of the fund-10%
- SepternaSEPN1.3% of the fund-5%
- Crinetics PharmaceuticalsCRNX1.1% of the fund-25%
- Dyne TherapeuticsDYN1.0% of the fund-4%
- Structure TherapeuticsGPCR1.0% of the fund-34%
- Taboola.comTBLA0.9% of the fund-16%
- Nebius GroupNBIS0.3% of the fund-54%
- MicrosoftMSFT0.3% of the fund-9%
- DatadogDDOG0.2% of the fund-26%
- JFrogFROG0.2% of the fund-26%
- Amazon.comAMZN0.2% of the fund-30%
- CrowdStrike HoldingsCRWD0.2% of the fund-57%
- Novabridge BiosciencesNBP<0.1% of the fund-33%
- WorkivaWK<0.1% of the fund-51%
- TeslaTSLA<0.1% of the fund-84%
Sold out
Sold their entire stake.
- Centessa Pharmaceuticals-100%
- Engene Holdings-100%
- Fulcrum TherapeuticsFULC-100%
- Wave Life SciencesWVE-100%
- uniQureQURE-100%
- Bicycle TherapeuticsBCYC-100%
- Forgent Power SolutionsFPS-100%
- Micron TechnologyMU-100%
- Amer SportsAS-100%
- Primo BrandsPRMB-100%
Holdings
- Beone MedicinesONC
- Share
- 2.7%
- Value
- $133m
- Shares
- 465,000
Held
- Parabilis MedicinesPBLS
- Share
- 1.7%
- Value
- $82m
- Shares
- 2,992,259
New
- Abivax SAABVX
- Share
- 1.6%
- Value
- $77m
- Shares
- 576,000
New
- Hemab Therapeutics HoldingsCOAG
- Share
- 1.6%
- Value
- $77m
- Shares
- 2,086,834
New
- Crinetics PharmaceuticalsCRNX
- Share
- 1.1%
- Value
- $53m
- Shares
- 1,420,788
-25%
- Kailera TherapeuticsKLRA
- Share
- 1.0%
- Value
- $49m
- Shares
- 2,214,286
New
- Structure TherapeuticsGPCR
- Share
- 1.0%
- Value
- $47m
- Shares
- 872,967
-34%
- DBV Technologies S ADBVT
- Share
- 0.6%
- Value
- $30m
- Shares
- 1,857,362
Held
- Seaport TherapeuticsSPTX
- Share
- 0.5%
- Value
- $24m
- Shares
- 1,095,316
New
- Damora Therapeutics
- Share
- 0.5%
- Value
- $23m
- Shares
- 900,000
Held
- Generate BiomedicinesGENB
- Share
- 0.3%
- Value
- $12m
- Shares
- 736,104
Held
- PDD HoldingsPDD
- Share
- 0.1%
- Value
- $7m
- Shares
- 95,000
+14%
- Satellos BioscienceMSLE
- Share
- 0.1%
- Value
- $7m
- Shares
- 892,074
Held
- Alibaba Group HldgBABA
- Share
- <0.1%
- Value
- $5m
- Shares
- 50,000
New
- Novabridge BiosciencesNBP
- Share
- <0.1%
- Value
- $4m
- Shares
- 2,004,739
-33%
- Odyssey TherapeuticsODTX
- Share
- <0.1%
- Value
- $4m
- Shares
- 200,000
New
| Company | Share of fund | Value | Shares | Change |
|---|---|---|---|---|
| Scholar Rock HoldingSRRK | 10.7% | $527m | 9,575,013 | -12% |
| Kymera TherapeuticsKYMR | 6.8% | $337m | 2,935,830 | -8% |
| ErascaERAS | 4.2% | $209m | 11,397,781 | Held |
| VeradermicsMANE | 4.1% | $204m | 1,655,374 | +10% |
| Tango TherapeuticsTNGX | 3.9% | $193m | 6,179,364 | +9% |
| Revolution MedicinesRVMD | 3.4% | $169m | 900,000 | -19% |
| Bicara TherapeuticsBCAX | 3.4% | $166m | 5,602,970 | -3% |
| Arrowhead PharmaceuticalsARWR | 2.8% | $140m | 1,715,476 | +6% |
| Beone MedicinesONC | 2.7% | $133m | 465,000 | Held |
| Edgewise TherapeuticsEWTX | 2.6% | $129m | 3,184,629 | -28% |
| Rhythm PharmaceuticalsRYTM | 2.6% | $126m | 1,136,275 | +57% |
| Lexicon PharmaceuticalsLXRX | 2.2% | $106m | 44,303,518 | Held |
| Enliven TherapeuticsELVN | 1.8% | $90m | 1,774,411 | +138% |
| Spyre TherapeuticsSYRE | 1.7% | $86m | 968,598 | +18% |
| Parabilis MedicinesPBLS | 1.7% | $82m | 2,992,259 | New |
| Xenon PharmaceuticalsXENE | 1.6% | $80m | 1,318,564 | Held |
| Solid BiosciencesSLDB | 1.6% | $77m | 7,690,405 | Held |
| Abivax SAABVX | 1.6% | $77m | 576,000 | New |
| Hemab Therapeutics HoldingsCOAG | 1.6% | $77m | 2,086,834 | New |
| Arcus BiosciencesRCUS | 1.5% | $75m | 2,420,430 | -20% |
| Cogent BiosciencesCOGT | 1.5% | $72m | 1,859,279 | +9% |
| Relay TherapeuticsRLAY | 1.4% | $68m | 3,650,000 | New |
| Taysha Gene TherapiesTSHA | 1.4% | $67m | 9,846,579 | +12% |
| Definium TherapeuticsDFTX | 1.4% | $67m | 1,419,493 | +54% |
| Stoke TherapeuticsSTOK | 1.3% | $65m | 1,995,347 | Held |
| Disc MedicineIRON | 1.3% | $65m | 888,401 | -10% |
| CytokineticsCYTK | 1.3% | $65m | 758,952 | +24% |
| SepternaSEPN | 1.3% | $64m | 1,900,000 | -5% |
| Olema PharmaceuticalsOLMA | 1.2% | $61m | 4,856,949 | +2% |
| Crinetics PharmaceuticalsCRNX | 1.1% | $53m | 1,420,788 | -25% |
| Kailera TherapeuticsKLRA | 1.0% | $49m | 2,214,286 | New |
| Dyne TherapeuticsDYN | 1.0% | $47m | 2,129,125 | -4% |
| Structure TherapeuticsGPCR | 1.0% | $47m | 872,967 | -34% |
| Taboola.comTBLA | 0.9% | $42m | 8,423,410 | -16% |
| Palvella TherapeuticsPVLA | 0.8% | $39m | 257,485 | Held |
| Silence TherapeuticsSLN | 0.7% | $36m | 3,311,438 | +14% |
| Denali TherapeuticsDNLI | 0.7% | $36m | 1,396,513 | Held |
| Remitly GlobalRELY | 0.7% | $35m | 1,543,271 | Held |
| Cullinan TherapeuticsCGEM | 0.7% | $34m | 1,893,410 | +59% |
| Capital One FinancialCOF | 0.7% | $34m | 171,615 | New |
| Trevi TherapeuticsTRVI | 0.7% | $33m | 1,786,867 | Held |
| Oric PharmaceuticalsORIC | 0.7% | $32m | 2,998,192 | Held |
| AlphabetGOOGL | 0.7% | $32m | 90,000 | +37% |
| DBV Technologies S ADBVT | 0.6% | $30m | 1,857,362 | Held |
| AbsciABSI | 0.6% | $29m | 2,474,764 | +37% |
| Sionna TherapeuticsSION | 0.5% | $27m | 610,515 | +104% |
| Rapport TherapeuticsRAPP | 0.5% | $27m | 641,469 | Held |
| Amylyx PharmaceuticalsAMLX | 0.5% | $27m | 1,480,586 | +20% |
| AnnexonANNX | 0.5% | $25m | 4,458,646 | +13% |
| Monopar TherapeuticsMNPR | 0.5% | $25m | 270,118 | Held |
| Oruka TherapeuticsORKA | 0.5% | $24m | 250,000 | New |
| Seaport TherapeuticsSPTX | 0.5% | $24m | 1,095,316 | New |
| Damora Therapeutics | 0.5% | $23m | 900,000 | Held |
| Tyra BiosciencesTYRA | 0.5% | $23m | 725,000 | New |
| Zura BioZURA | 0.4% | $22m | 3,734,866 | Held |
| Taiwan Semiconductor ManufacturingTSM | 0.4% | $21m | 44,700 | +6% |
| NvidiaNVDA | 0.4% | $19m | 95,000 | +7% |
| RezoluteRZLT | 0.4% | $17m | 3,328,287 | Held |
| MapLight TherapeuticsMPLT | 0.3% | $16m | 450,000 | Held |
| Neumora TherapeuticsNMRA | 0.3% | $14m | 8,497,822 | Held |
| Nebius GroupNBIS | 0.3% | $14m | 52,000 | -54% |
| MicrosoftMSFT | 0.3% | $14m | 37,500 | -9% |
| CytomX TherapeuticsCTMX | 0.3% | $13m | 3,457,711 | Held |
| Generate BiomedicinesGENB | 0.3% | $12m | 736,104 | Held |
| Inhibikase TherapeuticsIKT | 0.2% | $12m | 5,850,000 | Held |
| AdageneADAG | 0.2% | $11m | 2,666,666 | New |
| enGene TherapeuticsENGN | 0.2% | $11m | 6,256,662 | New |
| Whitehawk TherapeuticsWHWK | 0.2% | $11m | 2,337,102 | +12% |
| DatadogDDOG | 0.2% | $10m | 40,000 | -26% |
| ServiceNowNOW | 0.2% | $10m | 100,000 | +15% |
| BroadcomAVGO | 0.2% | $9m | 25,000 | +67% |
| IonQIONQ | 0.2% | $9m | 170,000 | Held |
| JFrogFROG | 0.2% | $9m | 95,500 | -26% |
| Oculis Holding AGOCS | 0.2% | $9m | 625,000 | New |
| IrenIREN | 0.2% | $8m | 175,000 | +306% |
| Amazon.comAMZN | 0.2% | $8m | 32,500 | -30% |
| CrowdStrike HoldingsCRWD | 0.2% | $8m | 10,000 | -57% |
| Design TherapeuticsDSGN | 0.2% | $8m | 523,212 | New |
| PDD HoldingsPDD | 0.1% | $7m | 95,000 | +14% |
| Satellos BioscienceMSLE | 0.1% | $7m | 892,074 | Held |
| DynatraceDT | 0.1% | $7m | 155,000 | +3% |
| Tenax TherapeuticsTENX | 0.1% | $6m | 427,141 | Held |
| vTv TherapeuticsVTVT | 0.1% | $6m | 163,000 | Held |
| Eloxx PharmaceuticalsELOX | 0.1% | $6m | 400,000 | New |
| AgomAb Therapeutics NVAGMB | 0.1% | $5m | 411,250 | Held |
| Alibaba Group HldgBABA | <0.1% | $5m | 50,000 | New |
| Korro BioKRRO | <0.1% | $5m | 347,718 | Held |
| Cellebrite DICLBT | <0.1% | $5m | 311,544 | Held |
| InvivydIVVD | <0.1% | $4m | 5,000,000 | +25% |
| OusterOUST | <0.1% | $4m | 67,500 | New |
| Palisade BIOPALI | <0.1% | $4m | 2,000,000 | New |
| Aeva TechnologiesAEVA | <0.1% | $4m | 145,459 | +32% |
| SeerSEER | <0.1% | $4m | 2,458,673 | Held |
| Novabridge BiosciencesNBP | <0.1% | $4m | 2,004,739 | -33% |
| GitlabGTLB | <0.1% | $4m | 125,000 | +25% |
| Odyssey TherapeuticsODTX | <0.1% | $4m | 200,000 | New |
| Foghorn TherapeuticsFHTX | <0.1% | $4m | 720,720 | Held |
| AgenusAGEN | <0.1% | $3m | 1,064,250 | Held |
| monday.comMNDY | <0.1% | $3m | 42,500 | +70% |
| ZoetisZTS | <0.1% | $3m | 35,000 | New |
Showing the largest 100 of 115.
Options (2)
- MicrosoftMSFT
- Type
- Call
- Value
- $9m
- Contracts
- 24,000
- AppleAAPL
- Type
- Call
- Value
- $7m
- Contracts
- 23,000
| Company | Type | Value | Contracts |
|---|---|---|---|
| MicrosoftMSFT | Call | $9m | 24,000 |
| AppleAAPL | Call | $7m | 23,000 |
Over time and by industry
Value over time
Jun '25
Dec '25
Jun '26
Value is up 154.9% since 30 June 2025.
Where the money is
Health care86.9%
Technology4.6%
Financial services0.9%
Media & telecom0.7%
Retail & consumer0.3%
Industrials0.1%
Other6.6%
From the fund's 13F filings. They list US stocks and options only, 45 days after each quarter, and leave out cash, bonds, shorts and foreign shares.