Siren, L.L.C.
Filing Date
Global Rank
#827
/ 8,623
▲ 56
· as of Mar 2026
Top Industry
Biotechnology
93.1%
3Y Alpha vs SPY
+18.9%
Period ended 4 months ago
Filed May 14, 2026 · 3mo
7 quarters · since Sep 2024
Clone Performance
Nov 2024–Jul 2026 · vs SPYHypothetical growth of buying every stock this filer reported holding, rebalancing on each filing and indexed to the same start. Option positions cannot be bought this way and are left out.
Cloned portfolio
+62.4%
SPY
+25.1%
Annualised alpha
+18.8%
Max drawdown
−43.7%
Estimate. 13F holdings are quarter-lagged, so the clone rebalances about 45 days after each period end — when the filing becomes public — and it excludes option and short positions. It tracks 100% of reported value on average across 7 quarters. Past performance does not predict future results.
Portfolio Concentration
100 tracked positions · as of Mar 31, 2026 · Δ vs Dec 31, 2025Top Position
14.8%
+0.3 pts
Top 5
34.8%
+1.4 pts
Top 10
49.8%
+2.6 pts
HHI
429
Diversified+12
Portfolio Trend
7 quarters · across all stocks
Sector Breakdown
As of Mar 31, 2026| Sector | % Portfolio | Value |
|---|---|---|
| Healthcare | 93.6% | $3,377,528,688 |
| Technology | 3.7% | $133,189,061 |
| Communication Services | 1.7% | $61,587,576 |
| Consumer Cyclical | 0.8% | $27,874,460 |
| Industrials | 0.1% | $2,927,000 |
| Financial Services | 0.1% | $1,836,718 |
| Real Estate | 0.0% | $1,497,000 |
| Consumer Defensive | 0.0% | $941,500 |
Last Quarter's Activity
Export CSVAdded To
Positions the filer increased
25 positions
| Ticker | Company | Δ Shares | Shares | Value | Open |
|---|---|---|---|---|---|
| LXRX | Lexicon Pharmaceuticals, Inc. | +5,384,615 | 44,303,518 | $69,113,488 | |
| ERAS | Erasca, Inc. | +2,486,997 | 11,244,246 | $181,931,900 | |
| ZURA | Zura Bio Ltd | +2,434,866 | 3,734,866 | $22,222,452 | |
| NMRA | Neumora Therapeutics, Inc. | +2,209,039 | 8,497,822 | $16,570,752 | |
| ORIC | Oric Pharmaceuticals, Inc. | +1,990,617 | 2,998,192 | $37,987,092 | |
| ENGN | enGene Therapeutics Inc. | +1,916,895 | 5,253,159 | $35,774,012 | |
| OLMA | Olema Pharmaceuticals, Inc. | +1,456,249 | 4,756,949 | $70,926,109 | |
| BCAX | Bicara Therapeutics Inc. | +586,001 | 5,802,970 | $115,421,073 | |
| XENE | Xenon Pharmaceuticals Inc. | +505,803 | 1,318,564 | $76,674,496 | |
| FULC | Fulcrum Therapeutics, Inc. | +400,000 | 2,350,000 | $18,024,500 | |
| CRNX | Crinetics Pharmaceuticals, Inc. | +396,000 | 1,903,636 | $69,140,059 | |
| GPCR | Structure Therapeutics Inc. | +250,000 | 1,328,698 | $64,043,243 | |
| RYTM | Rhythm Pharmaceuticals, Inc. | +225,536 | 725,511 | $63,097,691 | |
| PVLA | Palvella Therapeutics, Inc. | +182,485 | 257,485 | $32,095,505 | |
| CLBT | Cellebrite DI Ltd. | +161,544 | 311,544 | $4,293,076 | |
| ARWR | Arrowhead Pharmaceuticals, Inc. | +115,000 | 1,615,476 | $101,290,345 | |
| COGT | Cogent Biosciences, Inc. | +80,000 | 1,709,279 | $65,790,148 | |
| MNPR | Monopar Therapeutics | +57,820 | 270,118 | $14,799,765 | |
| NVDA | Nvidia Corp | +51,600 | 89,085 | $15,536,424 | |
| NOW | ServiceNow, Inc. | +51,460 | 87,090 | $9,105,259 | |
| GOOGL | Alphabet Inc. | +45,000 | 65,703 | $18,893,554 | |
| NBIS | Nebius Group N.V. | +37,396 | 113,614 | $11,788,588 | |
| FROG | JFrog Ltd | +35,200 | 128,816 | $6,045,334 | |
| DT | Dynatrace, Inc. | +34,771 | 150,000 | $5,547,000 | |
| MSFT | Microsoft Corp | +26,380 | 41,380 | $15,317,634 | |
| No positions match the current search. | |||||
Trimmed
Positions the filer reduced
18 positions
| Ticker | Company | Δ Shares | Shares | Value | Open |
|---|---|---|---|---|---|
| CNTA | Centessa Pharmaceuticals plc | −2,974,053 | 1,053,464 | $41,843,590 | |
| TNGX | Tango Therapeutics, Inc. | −2,508,269 | 5,657,105 | $118,346,636 | |
| SEER | Seer, Inc. | −1,541,327 | 2,458,673 | $4,130,570 | |
| TSHA | Taysha Gene Therapies, Inc. | −1,300,000 | 8,829,913 | $39,469,711 | |
| DYN | Dyne Therapeutics, Inc. | −1,273,816 | 2,229,125 | $40,414,036 | |
| TRVI | Trevi Therapeutics, Inc. | −500,000 | 1,786,867 | $21,317,323 | |
| BCYC | Bicycle Therapeutics PLC | −451,870 | 1,560,882 | $7,242,492 | |
| STOK | Stoke Therapeutics, Inc. | −252,000 | 1,995,347 | $64,968,498 | |
| RVMD | Revolution Medicines, Inc. | −224,095 | 1,110,980 | $108,042,805 | |
| KYMR | Kymera Therapeutics, Inc. | −100,000 | 3,186,830 | $265,431,070 | |
| EWTX | Edgewise Therapeutics, Inc. | −99,727 | 4,430,263 | $139,553,284 | |
| RELY | Remitly Global, Inc. | −75,000 | 1,543,271 | $24,183,056 | |
| RAPP | Rapport Therapeutics, Inc. | −67,000 | 641,469 | $20,071,565 | |
| MDLN | Medline Inc. | −50,000 | 25,000 | $1,112,500 | |
| BEKE | KE Holdings Inc. | −45,000 | 100,000 | $1,497,000 | |
| ONC | BeOne Medicines Ltd. | −35,000 | 465,000 | $138,091,050 | |
| PRMB | Primo Brands Corp | −25,000 | 50,000 | $941,500 | |
| AMZN | Amazon Com Inc | −4,859 | 46,641 | $9,713,921 | |
| No positions match the current search. | |||||
New Positions
Positions the filer opened this quarter
19 positions
| Ticker | Company | Shares | Value | Open |
|---|---|---|---|---|
| MANE | Veradermics, Inc | 1,505,374 | $95,064,368 | |
| CYTK | Cytokinetics Inc | 613,952 | $40,465,576 | |
| ELVN | Enliven Therapeutics, Inc. | 746,226 | $29,252,059 | |
| DMRA | Damora Therapeutics, Inc. | 900,000 | $23,310,000 | |
| ANNX | Annexon, Inc. | 3,958,646 | $21,930,898 | |
| DFTX | Definium Therapeutics, Inc. | 919,493 | $17,378,417 | |
| AMLX | Amylyx Pharmaceuticals, Inc. | 1,230,000 | $17,097,000 | |
| QURE | uniQure N.V. | 1,000,000 | $16,350,000 | |
| CTMX | CytomX Therapeutics, Inc. | 3,457,711 | $16,251,241 | |
| RZLT | Rezolute, Inc. | 3,328,287 | $10,151,275 | |
| GENB | Generate Biomedicines, Inc. | 736,104 | $9,201,300 | |
| ABSI | Absci Corp | 1,800,000 | $5,400,000 | |
| MSLE | Satellos Bioscience Inc. | 892,074 | $5,022,376 | |
| AGMB | Agomab Therapeutics NV | 411,250 | $4,314,012 | |
| FPS | Forgent Power Solutions, Inc. | 100,000 | $2,927,000 | |
| MU | Micron Technology Inc | 6,000 | $2,027,040 | |
| AS | Amer Sports, Inc. | 50,000 | $1,646,000 | |
| AEVA | Aeva Technologies, Inc. | 110,000 | $1,447,600 | |
| NU | Nu Holdings Ltd. | 25,000 | $359,250 | |
| No positions match the current search. | ||||
Sold Out
Positions the filer fully exited
25 positions
| Ticker | Company | Shares | Value | Open |
|---|---|---|---|---|
| APLS | Apellis Pharmaceuticals, Inc. | 2,578,396 | $64,769,307 | |
| ASND | Ascendis Pharma A/S | 235,862 | $50,295,212 | |
| ZYME | Zymeworks Inc. | 1,680,121 | $44,237,585 | |
| MLYS | Mineralys Therapeutics, Inc. | 699,999 | $25,402,963 | |
| IHS | IHS Holding Ltd | 2,357,520 | $17,587,099 | |
| UPB | Upstream Bio, Inc. | 588,450 | $15,976,417 | |
| BNTC | Benitec Biopharma Inc. | 775,000 | $10,439,250 | |
| LXEO | Lexeo Therapeutics, Inc. | 720,622 | $7,155,776 | |
| CRM | Salesforce, Inc. | 26,100 | $6,914,151 | |
| CMPS | COMPASS Pathways plc | 1,000,000 | $6,900,000 | |
| BLLN | BillionToOne, Inc. | 83,833 | $6,860,892 | |
| SVRA | Savara Inc | 1,000,000 | $6,030,000 | |
| XFOR | X4 Pharmaceuticals, Inc | 1,500,000 | $6,000,000 | |
| ALMS | Alumis Inc. | 500,000 | $4,880,000 | |
| META | Meta Platforms, Inc. | 7,169 | $4,732,185 | |
| PEPG | PepGen Inc. | 700,000 | $4,557,000 | |
| SGMT | Sagimet Biosciences Inc. | 724,771 | $4,290,644 | |
| ADBE | Adobe Inc. | 12,051 | $4,217,729 | |
| EDU | New Oriental Education & Technology Group Inc. | 62,000 | $3,411,860 | |
| ZS | Zscaler, Inc. | 12,000 | $2,699,040 | |
| BDTX | Black Diamond Therapeutics, Inc. | 1,046,517 | $2,543,036 | |
| QCOM | Qualcomm Inc/De | 14,000 | $2,394,700 | |
| ARM | Arm Holdings PLC /Uk | 21,500 | $2,350,165 | |
| TIL | Instil Bio, Inc. | 203,933 | $2,243,263 | |
| PANW | Palo Alto Networks Inc | 11,450 | $2,109,090 | |
| No positions match the current search. | ||||
100 tracked positions ·
$3,607,382,003 total
· filing declares
102 positions · $3,607,379,030
· as of Mar 31, 2026
All sectors
Communication Services
Consumer Cyclical
Consumer Defensive
Financial Services
Healthcare
Industrials
Real Estate
Technology
Showing 1–50
of 100 positions by value
· page 1 of 2
| Ticker | Company | Type | Shares | Value (USD) | % of Portfolio | History |
|---|---|---|---|---|---|---|
| SRRK |
Scholar Rock Holding Corp
Healthcare
|
Held | 10,825,013 | $532,157,639 | 14.75% | |
| KYMR |
Kymera Therapeutics, Inc.
Healthcare
|
Reduced | 3,186,830 | $265,431,070 | 7.36% | |
| ERAS |
Erasca, Inc.
Healthcare
|
Added | 11,244,246 | $181,931,900 | 5.04% | |
| EWTX |
Edgewise Therapeutics, Inc.
Healthcare
|
Reduced | 4,430,263 | $139,553,284 | 3.87% | |
| ONC |
BeOne Medicines Ltd.
Healthcare
|
Reduced | 465,000 | $138,091,050 | 3.83% | |
| TNGX |
Tango Therapeutics, Inc.
Healthcare
|
Reduced | 5,657,105 | $118,346,636 | 3.28% | |
| BCAX |
Bicara Therapeutics Inc.
Healthcare
|
Added | 5,802,970 | $115,421,073 | 3.20% | |
| RVMD |
Revolution Medicines, Inc.
Healthcare
|
Reduced | 1,110,980 | $108,042,805 | 3.00% | |
| ARWR |
Arrowhead Pharmaceuticals, Inc.
Healthcare
|
Added | 1,615,476 | $101,290,345 | 2.81% | |
| MANE |
Veradermics, Inc
Healthcare
|
NEW | 1,505,374 | $95,064,368 | 2.64% | |
| XENE |
Xenon Pharmaceuticals Inc.
Healthcare
|
Added | 1,318,564 | $76,674,496 | 2.13% | |
| OLMA |
Olema Pharmaceuticals, Inc.
Healthcare
|
Added | 4,756,949 | $70,926,109 | 1.97% | |
| CRNX |
Crinetics Pharmaceuticals, Inc.
Healthcare
|
Added | 1,903,636 | $69,140,059 | 1.92% | |
| LXRX |
Lexicon Pharmaceuticals, Inc.
Healthcare
|
Added | 44,303,518 | $69,113,488 | 1.92% | |
| COGT |
Cogent Biosciences, Inc.
Healthcare
|
Added | 1,709,279 | $65,790,148 | 1.82% | |
| STOK |
Stoke Therapeutics, Inc.
Healthcare
|
Reduced | 1,995,347 | $64,968,498 | 1.80% | |
| RCUS |
Arcus Biosciences, Inc.
Healthcare
|
Held | 3,007,077 | $64,952,863 | 1.80% | |
| GPCR |
Structure Therapeutics Inc.
Healthcare
|
Added | 1,328,698 | $64,043,243 | 1.78% | |
| IRON |
Disc Medicine, Inc.
Healthcare
|
Held | 988,401 | $63,198,359 | 1.75% | |
| RYTM |
Rhythm Pharmaceuticals, Inc.
Healthcare
|
Added | 725,511 | $63,097,691 | 1.75% | |
| SLDB |
Solid Biosciences Inc.
Healthcare
|
Held | 7,690,405 | $55,370,916 | 1.53% | |
| SEPN |
Septerna, Inc.
Healthcare
|
Held | 2,000,000 | $48,060,000 | 1.33% | |
| CNTA |
Centessa Pharmaceuticals plc
Healthcare
|
Reduced | 1,053,464 | $41,843,590 | 1.16% | |
| SYRE |
Spyre Therapeutics, Inc.
Healthcare
|
Held | 818,598 | $41,290,083 | 1.14% | |
| CYTK |
Cytokinetics Inc
Healthcare
|
NEW | 613,952 | $40,465,576 | 1.12% | |
| DYN |
Dyne Therapeutics, Inc.
Healthcare
|
Reduced | 2,229,125 | $40,414,036 | 1.12% | |
| TSHA |
Taysha Gene Therapies, Inc.
Healthcare
|
Reduced | 8,829,913 | $39,469,711 | 1.09% | |
| DBVT |
DBV Technologies S.A.
Healthcare
|
Held | 1,857,362 | $38,800,292 | 1.08% | |
| ORIC |
Oric Pharmaceuticals, Inc.
Healthcare
|
Added | 2,998,192 | $37,987,092 | 1.05% | |
| ENGN |
enGene Therapeutics Inc.
Healthcare
|
Added | 5,253,159 | $35,774,012 | 0.99% | |
| PVLA |
Palvella Therapeutics, Inc.
Healthcare
|
Added | 257,485 | $32,095,505 | 0.89% | |
| TBLA |
Taboola.com Ltd.
Communication Services
|
Held | 9,969,495 | $30,905,434 | 0.86% | |
| ELVN |
Enliven Therapeutics, Inc.
Healthcare
|
NEW | 746,226 | $29,252,059 | 0.81% | |
| DNLI |
Denali Therapeutics Inc.
Healthcare
|
Held | 1,396,513 | $26,813,049 | 0.74% | |
| RELY |
Remitly Global, Inc.
Technology
|
Reduced | 1,543,271 | $24,183,056 | 0.67% | |
| DMRA |
Damora Therapeutics, Inc.
Healthcare
|
NEW | 900,000 | $23,310,000 | 0.65% | |
| ZURA |
Zura Bio Ltd
Healthcare
|
Added | 3,734,866 | $22,222,452 | 0.62% | |
| ANNX |
Annexon, Inc.
Healthcare
|
NEW | 3,958,646 | $21,930,898 | 0.61% | |
| TRVI |
Trevi Therapeutics, Inc.
Healthcare
|
Reduced | 1,786,867 | $21,317,323 | 0.59% | |
| RAPP |
Rapport Therapeutics, Inc.
Healthcare
|
Reduced | 641,469 | $20,071,565 | 0.56% | |
| GOOGL |
Alphabet Inc.
Communication Services
|
Added | 65,703 | $18,893,554 | 0.52% | |
| FULC |
Fulcrum Therapeutics, Inc.
Healthcare
|
Added | 2,350,000 | $18,024,500 | 0.50% | |
| WVE |
Wave Life Sciences Ltd.
Healthcare
|
Held | 2,450,000 | $17,762,500 | 0.49% | |
| DFTX |
Definium Therapeutics, Inc.
Healthcare
|
NEW | 919,493 | $17,378,417 | 0.48% | |
| AMLX |
Amylyx Pharmaceuticals, Inc.
Healthcare
|
NEW | 1,230,000 | $17,097,000 | 0.47% | |
| CGEM |
Cullinan Therapeutics, Inc.
Healthcare
|
Held | 1,193,410 | $16,958,356 | 0.47% | |
| NMRA |
Neumora Therapeutics, Inc.
Healthcare
|
Added | 8,497,822 | $16,570,752 | 0.46% | |
| QURE |
uniQure N.V.
Healthcare
|
NEW | 1,000,000 | $16,350,000 | 0.45% | |
| CTMX |
CytomX Therapeutics, Inc.
Healthcare
|
NEW | 3,457,711 | $16,251,241 | 0.45% | |
| NVDA |
Nvidia Corp
Technology
|
Added | 89,085 | $15,536,424 | 0.43% |
Covers the securities this platform tracks: U.S.-listed common stock and the put/call positions reported on it. A 13F can also report security types outside that coverage — preferred shares, bonds, warrants, untracked share classes — so the filing's own declared total can exceed the figures above. The source filing is linked at the top of this table.