Investor
Siren, L.L.C.
CIK 0002005245 · filed 2026-05-14 · SEC filing
13F book
$3.61B
Positions
100
19 new · 32 sold
Largest name
14.8%
Scholar Rock Hldg Corp
Est. mark
$178M
Price effect on 81 names still held. Flow $76.9M.
| Name | Ticker | Shares | Value | Weight | Est. mark | Change |
|---|---|---|---|---|---|---|
| Scholar Rock Hldg Corp | — | 10.8M | $532.2M | 14.8% | $55.3M | Held |
| Kymera Therapeutics, Inc. | KYMR | 3.19M | $265.4M | 7.4% | $17.5M | Cut$9.68M |
| Erasca, Inc. | ERAS | 11.2M | $181.9M | 5.0% | $109.1M | Added$149.4M |
| Edgewise Therapeutics, Inc. | EWTX | 4.43M | $139.6M | 3.9% | $29.6M | Cut$27.1M |
| Beone Medicines Ltd | — | 465K | $138.1M | 3.8% | −$3.18M | Cut−$13.8M |
| Tango Therapeutics, Inc. | TNGX | 5.66M | $118.3M | 3.3% | $68.2M | Cut$46M |
| Bicara Therapeutics Inc. | BCAX | 5.8M | $115.4M | 3.2% | $16M | Added$27.6M |
| Revolution Medicines Inc | — | 1.11M | $108M | 3.0% | $19.6M | Cut$1.7M |
| Arrowhead Pharmaceuticals In | — | 1.62M | $101.3M | 2.8% | −$5.54M | Added$1.67M |
| Veradermics, Inc | MANE | 1.51M | $95.1M | 2.6% | — | New |
| Xenon Pharmaceuticals Inc. | XENE | 1.32M | $76.7M | 2.1% | $10.8M | Added$40.2M |
| Olema Pharmaceuticals, Inc. | OLMA | 4.76M | $70.9M | 2.0% | −$33.3M | Added−$11.6M |
| Crinetics Pharmaceuticals In | — | 1.9M | $69.1M | 1.9% | −$15.4M | Added−$1.04M |
| Lexicon Pharmaceuticals, Inc. | LXRX | 44.3M | $69.1M | 1.9% | $16M | Added$24.4M |
| Cogent Biosciences, Inc. | COGT | 1.71M | $65.8M | 1.8% | $4.84M | Added$7.92M |
| Stoke Therapeutics, Inc. | STOK | 2M | $65M | 1.8% | $1.64M | Cut−$6.36M |
| Arcus Biosciences, Inc. | RCUS | 3.01M | $65M | 1.8% | −$6.71M | Held |
| Structure Therapeutics Inc. | GPCR | 1.33M | $64M | 1.8% | −$23M | Added−$11M |
| Disc Medicine, Inc. | IRON | 988.4K | $63.2M | 1.8% | −$15.3M | Held |
| Rhythm Pharmaceuticals, Inc. | RYTM | 725.5K | $63.1M | 1.7% | −$10M | Added$9.58M |
| Solid Biosciences Inc. | SLDB | 7.69M | $55.4M | 1.5% | $12M | Held |
| Septerna, Inc. | SEPN | 2M | $48.1M | 1.3% | −$7.7M | Held |
| Centessa Pharmaceuticals Plc | — | 1.05M | $41.8M | 1.2% | $15.5M | Cut−$58.9M |
| Spyre Therapeutics, Inc. | SYRE | 818.6K | $41.3M | 1.1% | $14.5M | Held |
| Cytokinetics Inc | CYTK | 614K | $40.5M | 1.1% | — | New |
| Dyne Therapeutics, Inc. | DYN | 2.23M | $40.4M | 1.1% | −$3.19M | Cut−$28.1M |
| Taysha Gene Therapies, Inc. | TSHA | 8.83M | $39.5M | 1.1% | −$9.09M | Cut−$16.2M |
| Dbv Technologies S A | — | 1.86M | $38.8M | 1.1% | $3.19M | Held |
| Oric Pharmaceuticals, Inc. | ORIC | 3M | $38M | 1.1% | $4.52M | Added$29.7M |
| Engene Holdings Inc | — | 5.25M | $35.8M | 1.0% | −$7.41M | Added$5.65M |
| Palvella Therapeutics Inc Ne | — | 257.5K | $32.1M | 0.9% | $1.5M | Added$24.2M |
| Taboola.com Ltd. | TBLA | 9.97M | $30.9M | 0.9% | −$15.1M | Held |
| Enliven Therapeutics, Inc. | ELVN | 746.2K | $29.3M | 0.8% | — | New |
| Denali Therapeutics Inc. | DNLI | 1.4M | $26.8M | 0.7% | $3.76M | Held |
| Remitly Global, Inc. | RELY | 1.54M | $24.2M | 0.7% | $2.89M | Cut$1.85M |
| Galecto Inc | DMRA | 900K | $23.3M | 0.6% | — | New |
| Zura Bio Ltd | ZURA | 3.73M | $22.2M | 0.6% | $923K | Added$15.4M |
| Annexon, Inc. | ANNX | 3.96M | $21.9M | 0.6% | — | New |
| Trevi Therapeutics, Inc. | TRVI | 1.79M | $21.3M | 0.6% | −$1.05M | Cut−$7.31M |
| Rapport Therapeutics, Inc. | RAPP | 641.5K | $20.1M | 0.6% | $609.4K | Cut−$1.42M |
| Alphabet Inc | — | 65.7K | $18.9M | 0.5% | −$526.7K | Added$12.4M |
| Fulcrum Therapeutics, Inc. | FULC | 2.35M | $18M | 0.5% | −$7.1M | Added−$4.03M |
| Wave Life Sciences Ltd. | WVE | 2.45M | $17.8M | 0.5% | −$23.9M | Held |
| Definium Therape | DFTX | 919.5K | $17.4M | 0.5% | — | New |
| Amylyx Pharmaceuticals, Inc. | AMLX | 1.23M | $17.1M | 0.5% | — | New |
| Cullinan Therapeutics, Inc. | CGEM | 1.19M | $17M | 0.5% | $4.61M | Held |
| Neumora Therapeutics, Inc. | NMRA | 8.5M | $16.6M | 0.5% | $1.01M | Added$5.31M |
| Uniqure Nv | — | 1M | $16.4M | 0.5% | — | New |
| CytomX Therapeutics, Inc. | CTMX | 3.46M | $16.3M | 0.4% | — | New |
| Nvidia Corp | NVDA | 89.1K | $15.5M | 0.4% | −$453.6K | Added$8.55M |
| Silence Therapeutics Plc | — | 2.91M | $15.3M | 0.4% | −$2.36M | Held |
| Microsoft Corp | MSFT | 41.4K | $15.3M | 0.4% | −$1.7M | Added$8.06M |
| Monopar Therapeutics | MNPR | 270.1K | $14.8M | 0.4% | −$2.23M | Added$936.7K |
| Taiwan Semiconductor Mfg Ltd | — | 42.2K | $14.3M | 0.4% | $943.5K | Added$5.84M |
| Sionna Therapeutics, Inc. | SION | 300K | $12M | 0.3% | −$315K | Held |
| Nebius Group N.V. | NBIS | 113.6K | $11.8M | 0.3% | $1.53M | Added$5.41M |
| Rezolute, Inc. | RZLT | 3.33M | $10.2M | 0.3% | — | New |
| Inhibikase Therapeutics, Inc. | IKT | 5.85M | $9.83M | 0.3% | −$2.16M | Held |
| Amazon Com Inc | AMZN | 46.6K | $9.71M | 0.3% | −$1.05M | Cut−$2.17M |
| Generate Biomedicines, Inc. | GENB | 736.1K | $9.2M | 0.3% | — | New |
| MapLight Therapeutics, Inc. | MPLT | 450K | $9.15M | 0.3% | $1.24M | Held |
| ServiceNow, Inc. | NOW | 87.1K | $9.11M | 0.3% | −$1.73M | Added$3.65M |
| Crowdstrike Hldgs Inc | — | 23.1K | $9.01M | 0.3% | −$1.29M | Added$1.27M |
| PDD Holdings Inc. | PDD | 83.4K | $8.52M | 0.2% | −$710.7K | Added$1.33M |
| Tesla, Inc. | TSLA | 21.5K | $7.99M | 0.2% | −$117K | Added$7.32M |
| Novabridge Biosciences | NBP | 3M | $7.38M | 0.2% | −$4.56M | Held |
| Bicycle Therapeutics Plc | BCYC | 1.56M | $7.24M | 0.2% | −$3.81M | Cut−$7.01M |
| Whitehawk Therapeutics, Inc. | WHWK | 2.08M | $7.18M | 0.2% | $2.14M | Held |
| Tenax Therapeutics, Inc. | TENX | 427.1K | $6.83M | 0.2% | $1.62M | Held |
| vTv Therapeutics Inc. | VTVT | 163K | $6.46M | 0.2% | −$53.8K | Held |
| Datadog, Inc. | DDOG | 54.3K | $6.41M | 0.2% | −$653.5K | Added$1.46M |
| Jfrog Ltd | FROG | 128.8K | $6.05M | 0.2% | −$1.45M | Added$198.1K |
| Dynatrace, Inc. | DT | 150K | $5.55M | 0.2% | −$732.9K | Added$553K |
| Workiva Inc | WK | 92.5K | $5.52M | 0.2% | −$2.11M | Added−$1.31M |
| Absci Corp | ABSI | 1.8M | $5.4M | 0.1% | — | New |
| Invivyd, Inc. | IVVD | 4M | $5.2M | 0.1% | −$4.68M | Held |
| Satellos Bioscience Inc. | MSLE | 892.1K | $5.02M | 0.1% | — | New |
| Ionq Inc | — | 170K | $4.9M | 0.1% | −$2.73M | Held |
| Broadcom Inc. | AVGO | 15K | $4.64M | 0.1% | −$256.1K | Added$2.22M |
| Agomab Therapeutics Nv | AGMB | 411.3K | $4.31M | 0.1% | — | New |
| Cellebrite DI Ltd. | CLBT | 311.5K | $4.29M | 0.1% | −$638.6K | Added$1.59M |
| Seer, Inc. | SEER | 2.46M | $4.13M | 0.1% | −$368.8K | Cut−$3.19M |
| Korro Bio, Inc. | KRRO | 347.7K | $3.94M | 0.1% | $1.15M | Held |
| Agenus Inc | AGEN | 1.06M | $3.55M | 0.1% | $212.8K | Held |
| Foghorn Therapeutics Inc. | FHTX | 720.7K | $3.45M | 0.1% | −$446.8K | Held |
| Forgent Power Solutions, Inc. | FPS | 100K | $2.93M | 0.1% | — | New |
| Kalaris Therapeutics, Inc. | KLRS | 435.8K | $2.51M | 0.1% | −$1.16M | Held |
| Gitlab Inc. | GTLB | 100K | $2.16M | 0.1% | −$1.57M | Added−$1.55M |
| Micron Technology Inc | MU | 6K | $2.03M | 0.1% | — | New |
| monday.com Ltd. | MNDY | 25K | $1.73M | 0.0% | −$1.33M | Added−$780.8K |
| Gossamer Bio, Inc. | GOSS | 5.21M | $1.71M | 0.0% | −$14.4M | Held |
| Amer Sports, Inc. | AS | 50K | $1.65M | 0.0% | — | New |
| Ke Hldgs Inc | — | 100K | $1.5M | 0.0% | −$79K | Cut−$788.2K |
| Iren Limited | — | 43.1K | $1.48M | 0.0% | −$150.4K | Held |
| Rani Therapeutics Hldgs Inc | — | 2M | $1.47M | 0.0% | −$1.23M | Held |
| Aeva Technologies, Inc. | AEVA | 110K | $1.45M | 0.0% | — | New |
| Medline Inc. | MDLN | 25K | $1.11M | 0.0% | $62.5K | Cut−$2.04M |
| Figma, Inc. | FIG | 50K | $1.06M | 0.0% | −$405.7K | Added$122.8K |
| Primo Brands Corp | PRMB | 50K | $941.5K | 0.0% | $124K | Cut−$284.8K |
| Nu Hldgs Ltd | — | 25K | $359.3K | 0.0% | — | New |
Positions as of Q1 2026. 13F filings arrive up to 45 days after quarter-end and omit shorts. Values are quarter-end marks, as filed. Estimated mark is the price effect on shares still held — not realized P&L or investment advice.