Stocks/Funds/CIK 1306923

Palo Alto Investors LP

long-term holder
Quarterly 13F filings · Latest period 2026-03-31 · CIK 1306923
Assets
$586M
+33.0% YoY
Holdings
50
Lifetime alpha vs market
-11.35% annual
Average hold time
3.3 yr
median 1.8 yr

Quarterly history

Cum return -6% vs S&P +52% · α -58% lifetimeAUM $586M · peak $2.2BFlow $-114M (-16%)2016-062017-122019-062020-122022-062023-122025-062026-03
AUM ($B)fundS&P 500(gap = α)/ Flow in/out

Behavior signals (lifetime)

Dip response
-0.63%
trims when stocks drop
when a holding falls −10%+
Middle response
-5.82%
baseline attrition
Rally response
-6.10%
trims into rallies
when a holding rises +10%+

Top positions · 30

Ticker$ value% portYoYHold time
ACADACADIA Pharmaceuticals I$64M10.9%+34.0%10.3 yr
PTCTPTC Therapeutics, Inc.$63M10.7%+33.7%1.8 yr
BMRNBioMarin Pharmaceutical $39M6.6%-20.1%10.5 yr
UTHRUnited Therapeutics Corp$37M6.4%+92.4%10.5 yr
ANABAnaptysBio, Inc.$35M6.0%+198.4%5.8 yr
MIRMMirum Pharmaceuticals, I$30M5.1%+105.1%4.5 yr
DYNDyne Therapeutics, Inc.$30M5.1%+73.3%1.3 yr
BIIBBiogen Inc.$26M4.4%+34.0%5.5 yr
IRONDisc Medicine, Inc.$26M4.4%+28.8%1.0 yr
IOVAIovance Biotherapeutics,$22M3.8%+5.4%2.5 yr
SNDXSyndax Pharmaceuticals, $20M3.4%+90.1%6.3 yr
ANNXAnnexon, Inc.$16M2.8%+187.0%0.5 yr
FOLDAmicus Therapeutics, Inc$16M2.7%+77.2%10.5 yr
NVCRNovoCure Limited$14M2.4%-38.8%3.3 yr
RAREUltragenyx Pharmaceutica$12M2.1%-42.1%1.0 yr

Portfolio composition (YoY)

Industry mix
Biotechnology89.3%+5.1pp$523M
Drug Manufacturers - General4.4%-2.0pp$26M
Medical - Instruments & Supplies2.4%-1.7pp$14M
Medical - Devices1.8%-0.3pp$10M
Medical - Diagnostics & Research1.6%$9M
Insurance - Brokers0.3%-2.2pp$2M
Medical - Healthcare Plans0.1%-0.1pp$1M
Medical - Care Facilities0.1%$1M
Country
US92.7%+4.6pp
IE3.5%-2.9pp
JE2.4%-1.7pp
CA0.5%
CH0.3%
DE0.3%-0.2pp
GB0.3%-0.2pp
NL0.1%
Top 5: 40.6% · Top 10: 63.5% · Top 25: 91.7%

Winners

TickerPrev $PnLYoY %
FOLD$60M+0.05B77.2%
UTHR$32M+0.03B92.4%
ANAB$19M+0.03B198.4%
ACAD$44M+0.02B34.0%
BIIB$28M+0.01B34.0%

Losers

TickerPrev $PnLYoY %
BMRN$70M-0.01B-20.1%
NVCR$18M-0.01B-38.8%
PRTA$21M-0.00B-21.5%

Top buys this quarter · 15

MIRM Mirum Pharmaceuticals, Inc.+$16M
CLDX Celldex Therapeutics, Inc.new+$9M
ACAD ACADIA Pharmaceuticals Inc.+$64M
IRON Disc Medicine, Inc.+$5M
BCAX Bicara Therapeutics Inc. Commo+$5M
TVTX Travere Therapeutics, Inc.+$4M
DYN Dyne Therapeutics, Inc.+$3M
ANNX Annexon, Inc.+$3M
RARE Ultragenyx Pharmaceutical Inc.+$3M
UTHR United Therapeutics Corporatio+$3M

Top sells this quarter · 15

INSM Insmed Incorporatedexit$80M
FOLD Amicus Therapeutics, Inc.$59M
BIIB Biogen Inc.$8M
DNLI Denali Therapeutics Inc.$8M
CMPX Compass Therapeutics, Inc.$5M
CYTK Cytokinetics, Incorporated$5M
BMRN BioMarin Pharmaceutical Inc.$3M
IOVA Iovance Biotherapeutics, Inc.$19M
XENE Xenon Pharmaceuticals Inc.$3M
ANAB AnaptysBio, Inc.$33M

Quarterly history (TTM returns)

PeriodAUM# PosReturn (1yr)SPY (1yr)Alpha (1yr)Flow
2026-03-31$586M50+139.90%+17.59%+122.31%-0.11B
2025-12-31$718M49+118.14%+17.72%+100.42%+0.04B
2025-09-30$540M44+65.32%+17.52%+47.80%-0.04B
2025-06-30$469M44+35.30%+14.94%+20.36%-0.23B
2025-03-31$441M42-17.42%+8.30%-25.73%-0.02B
2024-12-31$523M41-17.30%+24.89%-42.18%-0.03B
2024-09-30$588M43-8.14%+36.04%-44.18%-0.03B
2024-06-30$609M36-21.19%+24.49%-45.68%-0.08B
2024-03-31$714M36-18.37%+29.62%-48.00%-0.08B
2023-12-31$896M32-27.40%+26.18%-53.58%-0.22B
2023-09-30$1.06B29-33.42%+21.57%-54.99%-0.02B
2023-06-30$1.24B30-18.61%+19.42%-38.03%+0.03B
2023-03-31$1.21B30-41.87%-7.82%-34.06%+0.28B
2022-12-31$1.17B29-3.50%+7.56%-11.06%-0.05B
2022-09-30$1.26B32+6.64%-4.93%+11.57%+0.04B
2022-06-30$1.15B33-28.47%-16.11%-12.36%+0.22B