Palo Alto Investors LP

CIK

1306923

Location

PALO ALTO, CA

Portfolio Value

Small $653,863,040

Diversification

Diversified

Filing Date

Global Rank

#2,267 / 8,623 ▼ 69 · as of Mar 2026

Top Industry

Biotechnology 83.0%

3Y Alpha vs SPY

-7.6%

Period ended 4 months ago

Filed May 15, 2026 · 3mo

25 quarters · since Mar 2020

Clone Performance

Jul 2023–Jul 2026 · vs SPY

Hypothetical 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

+36.5%

SPY

+65.3%

Annualised alpha

-7.3%

Max drawdown

−35.4%

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 13 quarters. Past performance does not predict future results.

Portfolio Concentration

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

Top Position

10.4%

−1.5 pts

Top 5

41.4%

−5.8 pts

Top 10

63.8%

−3.9 pts

HHI

529

Diversified−67

Portfolio Trend

25 quarters · across all stocks

Sector Breakdown

As of Mar 31, 2026

Sector	% Portfolio	Value	Positions
Healthcare	99.7%	$651,950,232	50
Financial Services	0.3%	$1,912,808	1

Last Quarter's Activity

Export CSV

Mar 31, 2026 vs Dec 31, 2025

Added To

Positions the filer increased

17 positions

Ticker	Company	Δ Shares	Shares	Value
ANNX	Annexon, Inc.	+563,898	2,948,090	$16,332,418
ACAD	Acadia Pharmaceuticals Inc	+388,664	2,872,695	$63,946,190
BCAX	Bicara Therapeutics Inc.	+251,833	550,408	$10,947,615
TSHA	Taysha Gene Therapies, Inc.	+208,187	1,391,382	$6,219,477
DYN	Dyne Therapeutics, Inc.	+180,775	1,652,972	$29,968,382
MIRM	Mirum Pharmaceuticals, Inc.	+168,754	325,175	$30,039,666
RARE	Ultragenyx Pharmaceutical Inc.	+135,201	596,495	$12,496,570
TVTX	Travere Therapeutics, Inc.	+119,734	230,453	$6,846,758
IRON	Disc Medicine, Inc.	+84,263	401,719	$25,685,912
SNDX	Syndax Pharmaceuticals Inc	+70,479	864,986	$20,206,072
CDNA	CareDx, Inc.	+53,650	531,870	$9,233,263
ACRS	Aclaris Therapeutics, Inc.	+46,590	1,613,430	$6,050,362
PTCT	Ptc Therapeutics, Inc.	+17,691	921,607	$62,789,084
STOK	Stoke Therapeutics, Inc.	+12,609	84,631	$2,755,585
UTHR	UNITED THERAPEUTICS Corp	+4,623	62,809	$37,244,480
CAPR	Capricor Therapeutics, Inc.	+3,459	229,763	$6,984,795
AGIO	Agios Pharmaceuticals, Inc.	+1,102	213,601	$7,226,121
No positions match the current search.

Trimmed

Positions the filer reduced

17 positions

Ticker	Company	Δ Shares	Shares	Value
FOLD	AMICUS THERAPEUTICS, INC.	−4,092,722	1,113,045	$16,094,630
CMPX	Compass Therapeutics, Inc.	−1,017,915	1,514,504	$8,011,726
IOVA	Iovance Biotherapeutics, Inc.	−767,113	6,349,563	$22,286,966
DNLI	Denali Therapeutics Inc.	−406,657	234,582	$4,503,974
PRTA	Prothena Corp Public Ltd Co	−111,942	1,208,568	$11,747,280
INSM	INSMED Inc	−74,213	415,269	$67,904,786
ALDX	Aldeyra Therapeutics, Inc.	−69,756	155,709	$263,148
BMRN	Biomarin Pharmaceutical Inc	−61,074	685,182	$38,705,931
ANAB	Anaptysbio, Inc	−51,871	638,161	$35,392,377
EHTH	eHealth, Inc.	−48,632	1,482,797	$1,912,808
XENE	Xenon Pharmaceuticals Inc.	−45,174	51,345	$2,985,711
BIIB	Biogen Inc.	−42,852	140,719	$25,798,014
NUVB	Nuvation Bio Inc.	−29,233	508,846	$2,182,949
PYXS	Pyxis Oncology, Inc.	−26,911	1,010,510	$1,475,344
BCYC	Bicycle Therapeutics PLC	−19,181	201,890	$936,769
NVCR	NovoCure Ltd	−18,525	1,280,439	$13,956,785
CRSP	CRISPR Therapeutics AG	−1,621	39,605	$1,884,009
No positions match the current search.

New Positions

Positions the filer opened this quarter

5 positions

Ticker	Company	Shares	Value
CLDX	Celldex Therapeutics, Inc.	296,408	$9,402,061
CYTK	Cytokinetics Inc	32,195	$2,121,972
VSTM	Verastem, Inc.	246,093	$1,304,292
MDGL	Madrigal Pharmaceuticals, Inc.	1,787	$935,440
XERS	Xeris Biopharma Holdings, Inc.	104,410	$605,578
No positions match the current search.

Sold Out

Positions the filer fully exited

2 positions

Ticker	Company	Shares	Value
GOSS	Gossamer Bio, Inc.	4,471,592	$13,861,935
AKTX	Akari Therapeutics Plc	146,024	$42,200
No positions match the current search.

Portfolio Positions

Compact Export CSV View 13F filing

51 tracked positions · $653,863,040 total · filing declares 51 positions · $653,863,097 · as of Mar 31, 2026

All sectors Financial Services Healthcare

Showing 1–50 of 51 positions by value · page 1 of 2

Ticker	Company	Type	Shares	Δ Shares	Value (USD)	% Δ Value	% of Portfolio
INSM	INSMED Inc Healthcare	Reduced	415,269	-74,213	$67,904,786	−20.3%	10.39%
ACAD	Acadia Pharmaceuticals Inc Healthcare	Added	2,872,695	+388,664	$63,946,190	−3.6%	9.78%
PTCT	Ptc Therapeutics, Inc. Healthcare	Added	921,607	+17,691	$62,789,084	−8.6%	9.60%
BMRN	Biomarin Pharmaceutical Inc Healthcare	Reduced	685,182	-61,074	$38,705,931	−12.7%	5.92%
UTHR	UNITED THERAPEUTICS Corp Healthcare	Added	62,809	+4,623	$37,244,480	+31.4%	5.70%
ANAB	Anaptysbio, Inc Healthcare	Reduced	638,161	-51,871	$35,392,377	+5.8%	5.41%
MIRM	Mirum Pharmaceuticals, Inc. Healthcare	Added	325,175	+168,754	$30,039,666	+143.1%	4.59%
DYN	Dyne Therapeutics, Inc. Healthcare	Added	1,652,972	+180,775	$29,968,382	+4.1%	4.58%
BIIB	Biogen Inc. Healthcare	Reduced	140,719	-42,852	$25,798,014	−20.1%	3.95%
IRON	Disc Medicine, Inc. Healthcare	Added	401,719	+84,263	$25,685,912	+1.9%	3.93%
IOVA	Iovance Biotherapeutics, Inc. Healthcare	Reduced	6,349,563	-767,113	$22,286,966	+14.7%	3.41%
SNDX	Syndax Pharmaceuticals Inc Healthcare	Added	864,986	+70,479	$20,206,072	+21.0%	3.09%
ANNX	Annexon, Inc. Healthcare	Added	2,948,090	+563,898	$16,332,418	+36.5%	2.50%
FOLD	AMICUS THERAPEUTICS, INC. Healthcare	Reduced	1,113,045	-4,092,722	$16,094,630	−78.3%	2.46%
NVCR	NovoCure Ltd Healthcare	Reduced	1,280,439	-18,525	$13,956,785	−16.9%	2.13%
RARE	Ultragenyx Pharmaceutical Inc. Healthcare	Added	596,495	+135,201	$12,496,570	+17.8%	1.91%
PRTA	Prothena Corp Public Ltd Co Healthcare	Reduced	1,208,568	-111,942	$11,747,280	−6.8%	1.80%
BCAX	Bicara Therapeutics Inc. Healthcare	Added	550,408	+251,833	$10,947,615	+117.9%	1.67%
CLDX	Celldex Therapeutics, Inc. Healthcare	NEW	296,408	NEW	$9,402,061	NEW	1.44%
CDNA	CareDx, Inc. Healthcare	Added	531,870	+53,650	$9,233,263	+2.5%	1.41%
ALKS	Alkermes plc. Healthcare	Held	242,560	0	$8,576,921	+26.4%	1.31%
CMPX	Compass Therapeutics, Inc. Healthcare	Reduced	1,514,504	-1,017,915	$8,011,726	−41.1%	1.23%
AGIO	Agios Pharmaceuticals, Inc. Healthcare	Added	213,601	+1,102	$7,226,121	+24.9%	1.11%
ALGN	Align Technology Inc Healthcare	Held	41,520	0	$7,117,773	+9.8%	1.09%
CAPR	Capricor Therapeutics, Inc. Healthcare	Added	229,763	+3,459	$6,984,795	+6.9%	1.07%
TVTX	Travere Therapeutics, Inc. Healthcare	Added	230,453	+119,734	$6,846,758	+61.8%	1.05%
TSHA	Taysha Gene Therapies, Inc. Healthcare	Added	1,391,382	+208,187	$6,219,477	−4.4%	0.95%
ACRS	Aclaris Therapeutics, Inc. Healthcare	Added	1,613,430	+46,590	$6,050,362	+28.3%	0.93%
DNLI	Denali Therapeutics Inc. Healthcare	Reduced	234,582	-406,657	$4,503,974	−57.5%	0.69%
XENE	Xenon Pharmaceuticals Inc. Healthcare	Reduced	51,345	-45,174	$2,985,711	−31.0%	0.46%
ORKA	Oruka Therapeutics, Inc. Healthcare	Held	59,985	0	$2,942,264	+61.8%	0.45%
STOK	Stoke Therapeutics, Inc. Healthcare	Added	84,631	+12,609	$2,755,585	+20.5%	0.42%
EW	Edwards Lifesciences Corp Healthcare	Held	33,640	0	$2,693,891	−6.1%	0.41%
NBIX	Neurocrine Biosciences Inc Healthcare	Held	18,117	0	$2,386,733	−7.1%	0.37%
NUVB	Nuvation Bio Inc. Healthcare	Reduced	508,846	-29,233	$2,182,949	−54.7%	0.33%
CYTK	Cytokinetics Inc Healthcare	NEW	32,195	NEW	$2,121,972	NEW	0.32%
EHTH	eHealth, Inc. Financial Services	Reduced	1,482,797	-1,580,061	$1,912,808	−86.4%	0.29%
CRSP	CRISPR Therapeutics AG Healthcare	Reduced	39,605	-1,621	$1,884,009	−12.9%	0.29%
BNTX	BioNTech SE Healthcare	Held	19,614	0	$1,743,292	−6.6%	0.27%
PYXS	Pyxis Oncology, Inc. Healthcare	Reduced	1,010,510	-26,911	$1,475,344	+23.7%	0.23%
VSTM	Verastem, Inc. Healthcare	NEW	246,093	NEW	$1,304,292	NEW	0.20%
BCYC	Bicycle Therapeutics PLC Healthcare	Reduced	201,890	-19,181	$936,769	−40.1%	0.14%
MDGL	Madrigal Pharmaceuticals, Inc. Healthcare	NEW	1,787	NEW	$935,440	NEW	0.14%
HUM	Humana Inc Healthcare	Held	3,985	0	$690,959	−32.3%	0.11%
CMPS	COMPASS Pathways plc Healthcare	Held	115,616	0	$639,356	−19.9%	0.10%
XERS	Xeris Biopharma Holdings, Inc. Healthcare	NEW	104,410	NEW	$605,578	NEW	0.09%
ABEO	Abeona Therapeutics Inc. Healthcare	Held	108,865	0	$487,715	−15.0%	0.07%
INSP	Inspire Medical Systems, Inc. Healthcare	Held	8,772	0	$452,459	−44.1%	0.07%
URGN	UroGen Pharma Ltd. Healthcare	Held	24,500	0	$440,510	−23.2%	0.07%
PRQR	ProQR Therapeutics N.V. Healthcare	Held	188,807	0	$305,867	−19.8%	0.05%

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.