Siren, L.L.C.

CIK

2005245

Location

New York, NY

Portfolio Value

Mid $3,590,811,251

Diversification

Diversified

Filing Date

Global Rank

#831 / 8,586 ▲ 52

Top Industry

Biotechnology 93.1%

3Y Alpha vs SPY

+9.7%

Period ended 3 months ago

Filed May 14, 2026 · 33d

7 quarters · since Sep 2024

Clone Performance

Nov 2024–Jun 2026 · vs SPY

Hypothetical growth of cloning every reported 13F position and rebalancing on each filing, indexed to the same start.

Cloned portfolio

+47.0%

SPY

+29.7%

Annualised alpha

+9.7%

Max drawdown

−42.4%

Estimate. 13F holdings are quarter-lagged and long-only, so the clone rebalances about 45 days after each period end — when the filing becomes public — and excludes options and short positions. Past performance does not predict future results.

Portfolio Concentration

99 positions · as of Mar 31, 2026 · Δ vs Dec 31, 2025

Top Position

14.8%

+0.3 pts

Top 5

35.0%

+1.4 pts

Top 10

50.0%

+2.7 pts

HHI

433

Diversified+13

Portfolio Trend

7 quarters · across all stocks

Sector Breakdown

As of Mar 31, 2026

Sector	% Portfolio	Value	Positions
Healthcare	93.6%	$3,360,957,936	69
Technology	3.7%	$133,189,061	18
Communication Services	1.7%	$61,587,576	3
Consumer Cyclical	0.8%	$27,874,460	4
Industrials	0.1%	$2,927,000	1
Financial Services	0.1%	$1,836,718	2
Real Estate	0.0%	$1,497,000	1
Consumer Defensive	0.0%	$941,500	1

Last Quarter's Activity

Export CSV

Mar 31, 2026 vs Dec 31, 2025

Added To

Positions the filer increased

25 positions

Ticker	Company	Δ Shares	Shares	Value
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
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
FIG	Figma, Inc.	+25,000	50,000	$1,057,000
No positions match the current search.

Trimmed

Positions the filer reduced

18 positions

Ticker	Company	Δ Shares	Shares	Value
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
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
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.

Portfolio Positions

Compact Export CSV View 13F filing

99 positions · $3,590,811,251 total · as of Mar 31, 2026

All sectors Communication Services Consumer Cyclical Consumer Defensive Financial Services Healthcare Industrials Real Estate Technology

Showing 1–50 of 99 positions by value · page 1 of 2

Ticker	Company	Type	Shares	Δ Shares	Value (USD)	% Δ Value	% of Portfolio
NU	Nu Holdings Ltd. Financial Services	NEW	25,000	NEW	$359,250	NEW	0.01%
PRMB	Primo Brands Corp Consumer Defensive	Reduced	50,000	-25,000	$941,500	−23.2%	0.03%
FIG	Figma, Inc. Technology	Added	50,000	+25,000	$1,057,000	+13.1%	0.03%
MDLN	Medline Inc. Healthcare	Reduced	25,000	-50,000	$1,112,500	−64.7%	0.03%
AEVA	Aeva Technologies, Inc. Technology	NEW	110,000	NEW	$1,447,600	NEW	0.04%
RANI	Rani Therapeutics Holdings, Inc. Healthcare	Held	2,000,000	0	$1,470,000	−45.6%	0.04%
IREN	IREN Ltd Financial Services	Held	43,100	0	$1,477,468	−9.2%	0.04%
BEKE	KE Holdings Inc. Real Estate	Reduced	100,000	-45,000	$1,497,000	−34.5%	0.04%
AS	Amer Sports, Inc. Consumer Cyclical	NEW	50,000	NEW	$1,646,000	NEW	0.05%
GOSS	Gossamer Bio, Inc. Healthcare	Held	5,208,968	0	$1,713,750	−89.4%	0.05%
MNDY	monday.com Ltd. Technology	Added	25,000	+8,000	$1,727,750	−31.1%	0.05%
MU	Micron Technology Inc Technology	NEW	6,000	NEW	$2,027,040	NEW	0.06%
GTLB	Gitlab Inc. Technology	Added	100,000	+1,000	$2,164,000	−41.8%	0.06%
KLRS	Kalaris Therapeutics, Inc. Healthcare	Held	435,798	0	$2,514,554	−31.6%	0.07%
FPS	Forgent Power Solutions, Inc. Industrials	NEW	100,000	NEW	$2,927,000	NEW	0.08%
FHTX	Foghorn Therapeutics Inc. Healthcare	Held	720,720	0	$3,445,041	−11.5%	0.10%
AGEN	Agenus Inc Healthcare	Held	1,064,250	0	$3,554,595	+6.4%	0.10%
KRRO	Korro Bio, Inc. Healthcare	Held	347,718	0	$3,936,167	+41.3%	0.11%
SEER	Seer, Inc. Healthcare	Reduced	2,458,673	-1,541,327	$4,130,570	−43.6%	0.12%
CLBT	Cellebrite DI Ltd. Technology	Added	311,544	+161,544	$4,293,076	+58.7%	0.12%
AGMB	Agomab Therapeutics NV Healthcare	NEW	411,250	NEW	$4,314,012	NEW	0.12%
AVGO	Broadcom Inc. Technology	Added	15,000	+8,000	$4,642,650	+91.6%	0.13%
IONQ	IonQ, Inc. Technology	Held	170,000	0	$4,901,100	−35.7%	0.14%
MSLE	Satellos Bioscience Inc. Healthcare	NEW	892,074	NEW	$5,022,376	NEW	0.14%
IVVD	Invivyd, Inc. Healthcare	Held	4,000,000	0	$5,200,000	−47.4%	0.14%
ABSI	Absci Corp Healthcare	NEW	1,800,000	NEW	$5,400,000	NEW	0.15%
WK	Workiva Inc Technology	Added	92,500	+13,377	$5,515,775	−19.2%	0.15%
DT	Dynatrace, Inc. Technology	Added	150,000	+34,771	$5,547,000	+11.1%	0.15%
FROG	JFrog Ltd Technology	Added	128,816	+35,200	$6,045,334	+3.4%	0.17%
DDOG	Datadog, Inc. Technology	Added	54,300	+17,875	$6,410,115	+29.4%	0.18%
VTVT	vTv Therapeutics Inc. Healthcare	Held	163,000	0	$6,464,580	−0.8%	0.18%
TENX	Tenax Therapeutics, Inc. Healthcare	Held	427,141	0	$6,829,984	+31.2%	0.19%
WHWK	Whitehawk Therapeutics, Inc. Healthcare	Held	2,082,000	0	$7,182,900	+42.6%	0.20%
BCYC	Bicycle Therapeutics PLC Healthcare	Reduced	1,560,882	-451,870	$7,242,492	−49.2%	0.20%
NBP	NovaBridge Biosciences Healthcare	Held	3,000,000	0	$7,380,000	−38.2%	0.21%
TSLA	Tesla, Inc. Consumer Cyclical	Added	21,500	+20,000	$7,992,625	+1084.8%	0.22%
PDD	PDD Holdings Inc. Consumer Cyclical	Added	83,401	+20,000	$8,521,914	+18.5%	0.24%
CRWD	CrowdStrike Holdings, Inc. Technology	Added	23,070	+6,570	$9,006,758	+16.4%	0.25%
NOW	ServiceNow, Inc. Technology	Added	87,090	+51,460	$9,105,259	+66.8%	0.25%
MPLT	MapLight Therapeutics, Inc. Healthcare	Held	450,000	0	$9,148,500	+15.7%	0.25%
GENB	Generate Biomedicines, Inc. Healthcare	NEW	736,104	NEW	$9,201,300	NEW	0.26%
AMZN	Amazon Com Inc Consumer Cyclical	Reduced	46,641	-4,859	$9,713,921	−18.3%	0.27%
IKT	Inhibikase Therapeutics, Inc. Healthcare	Held	5,850,000	0	$9,828,000	−18.0%	0.27%
RZLT	Rezolute, Inc. Healthcare	NEW	3,328,287	NEW	$10,151,275	NEW	0.28%
NBIS	Nebius Group N.V. Communication Services	Added	113,614	+37,396	$11,788,588	+84.8%	0.33%
SION	Sionna Therapeutics, Inc. Healthcare	Held	300,000	0	$12,027,000	−2.6%	0.33%
TSM	Taiwan Semiconductor Manufacturing Co Ltd Technology	Added	42,200	+14,500	$14,261,490	+69.4%	0.40%
MNPR	Monopar Therapeutics Healthcare	Added	270,118	+57,820	$14,799,765	+6.8%	0.41%
MSFT	Microsoft Corp Technology	Added	41,380	+26,380	$15,317,634	+111.2%	0.43%
SLN	Silence Therapeutics plc Healthcare	Held	2,911,438	0	$15,343,278	−13.3%	0.43%