HolderBook

Palo Alto Investors LP

Reported holdings as of Q2 2026, from 31 quarterly filings.

This filer last reported in Q2 2026; the most recent quarter on file across all filers is Q3 2026. Firms that restructure stop filing under one CIK and start under another, so a successor entity may hold these positions now under a similar name.

CIK
1306923
Reported value
$2.2B
Positions
54
Top 10 weight
56.1%
Filed
2026-08-17
Days after quarter end
48

Holdings

Download these holdings as CSV

SecurityTickerValue SharesWeightWeight change Held Change
PTC THERAPEUTICS INCPTCT$224.9M2,756,53810.36%+0.75pp8q+199.1%+$149.7M
ACADIA PHARMACEUTICALS INCACAD$144.9M5,728,1926.67%-3.10pp31q+99.4%+$72.2M
INSMED INCINSM$132.4M1,241,9406.10%-4.29pp31q+199.1%+$88.1M
ANAPTYSBIO INCANAB$122.2M1,810,4675.63%+0.22pp24q+183.7%+$79.1M
BIOMARIN PHARMACEUTICAL INCBMRN$117.2M2,048,3315.40%-0.52pp31q+198.9%+$78.0M
DYNE THERAPEUTICS INCDYN$109.8M4,942,5635.06%+0.47pp6q+199.0%+$73.1M
UNITED THERAPEUTICS CORP DELUTHR$101.7M187,7614.69%-1.01pp31q+198.9%+$67.7M
DISC MEDICINE INCIRON$91.4M1,249,9384.21%+0.28pp5q+211.1%+$62.0M
BIOGEN INCBIIB$90.9M420,8374.19%+0.24pp23q+199.1%+$60.5M
MIRUM PHARMACEUTICALS INC$81.7M697,6163.76%-newDEBT
ACADIA HEALTHCARE COMPANY INACHC$72.5M2,864,0963.34%-newNEW
IOVANCE BIOTHERAPEUTICS INCIOVA$66.1M15,888,6273.04%-0.36pp11q+150.2%+$39.7M
ULTRAGENYX PHARMACEUTICAL INRARE$59.8M1,789,4852.75%+0.84pp5q+200.0%+$39.8M
NOVOCURE LTDNVCR$58.2M3,841,3172.68%+0.55pp14q+200.0%+$38.8M
SYNDAX PHARMACEUTICALS INCSNDX$56.7M2,594,9582.61%-0.48pp26q+200.0%+$37.8M
ANNEXON INCANNX$50.5M8,844,2702.33%-0.17pp3q+200.0%+$33.7M
BICARA THERAPEUTICS INCBCAX$49.0M1,651,2242.26%+0.58pp3q+200.0%+$32.7M
CAREDX INCCDNA$45.5M1,595,6102.09%+0.68pp4q+200.0%+$30.3M
CELLDEX THERAPEUTICS INC NEWCLDX$44.6M1,199,5682.06%+0.62pp2q+304.7%+$33.6M
MIRUM PHARMACEUTICALS INCMIRM$40.8M348,8081.88%-2.71pp19q+7.3%+$2.8M
COMPASS THERAPEUTICS INCCMPX$38.3M17,495,4391.76%+0.54pp3q+1055.2%+$35.0M
ALKERMES PLCALKS$38.1M727,6801.76%+0.44pp23q+200.0%+$25.4M
FIRST TRACKS BIOTHERAPEUTICSTRAX$36.4M1,810,4671.68%-newNEW
PROTHENA CORP PLCPRTA$33.6M3,429,4651.55%-0.25pp31q+183.8%+$21.7M
TRAVERE THERAPEUTICS INCTVTX$28.6M502,5751.32%+0.27pp23q+118.1%+$15.5M
TAYSHA GENE THERAPIES INCTSHA$28.4M4,174,1461.31%+0.36pp11q+200.0%+$19.0M
ACLARIS THERAPEUTICS INCACRS$25.6M4,840,2901.18%+0.25pp10q+200.0%+$17.1M
AGIOS PHARMACEUTICALS INCAGIO$23.8M640,8031.10%-0.01pp6q+200.0%+$15.9M
CAPRICOR THERAPEUTICS INCCAPR$16.6M689,2890.76%-0.30pp3q+200.0%+$11.1M
ALIGN TECHNOLOGY INCALGN$15.9M94,1670.73%-0.36pp31q+126.8%+$8.9M
ORUKA THERAPEUTICS INCORKA$9.6M100,6380.44%-0.01pp4q+67.8%+$3.9M
XENON PHARMACEUTICALS INCXENE$9.3M154,0350.43%-0.03pp3q+200.0%+$6.2M
NEUROCRINE BIOSCIENCES INCNBIX$9.2M54,3510.42%+0.06pp6q+200.0%+$6.1M
EDWARDS LIFESCIENCES CORPEW$9.1M100,9200.42%+0.01pp8q+200.0%+$6.1M
STOKE THERAPEUTICS INCSTOK$8.3M253,8930.38%-0.04pp10q+200.0%+$5.5M
CYTOKINETICS INCCYTK$8.2M96,5850.38%+0.05pp2q+200.0%+$5.5M
PYXIS ONCOLOGY INCPYXS$7.8M2,592,8310.36%+0.13pp8q+156.6%+$4.8M
EHEALTH INCEHTH$6.6M4,448,3910.31%+0.01pp24q+200.0%+$4.4M
CRISPR THERAPEUTICS AGCRSP$6.5M118,8150.30%+0.01pp5q+200.0%+$4.3M
SAGIMET BIOSCIENCES INCSGMT$5.8M750,0000.27%-newNEW
NUVATION BIO INCNUVB$5.6M979,8270.26%-0.08pp10q+92.6%+$2.7M
BIONTECH SEBNTX$5.5M58,8420.25%-0.01pp8q+200.0%+$3.7M
COMPASS PATHWAYS PLCCMPS$4.9M346,8480.23%+0.13pp3q+200.0%+$3.3M
HUMANA INCHUM$4.7M11,9550.22%+0.11pp10q+200.0%+$3.2M
NEWAMSTERDAM PHARMA COMPANYNAMS$4.5M133,0770.21%-newNEW
VERASTEM INCVSTM$3.5M929,0550.16%-0.04pp2q+277.5%+$2.6M
MADRIGAL PHARMACEUTICALS INCMDGL$2.9M5,3610.13%-0.01pp2q+200.0%+$1.9M
UROGEN PHARMA LTDURGN$2.7M73,5000.12%+0.06pp26q+200.0%+$1.8M
BICYCLE THERAPEUTICS PLCBCYC$2.6M605,6700.12%-0.02pp8q+200.0%+$1.7M
XERIS BIOPHARMA HOLDINGS INCXERS$2.5M313,2300.11%+0.02pp2q+200.0%+$1.7M
ABEONA THERAPEUTICS INCABEO$2.0M326,5950.09%+0.02pp8q+200.0%+$1.3M
INSPIRE MED SYS INCINSP$1.2M26,3160.05%-0.02pp3q+200.0%+$782.6K
PROQR THRAPEUTICS N VPRQR$1.1M566,4210.05%flat4q+200.0%+$702.4K
ALDEYRA THERAPEUTICS INCALDX$995.0K467,1270.05%+0.01pp29q+200.0%+$663.3K

By sector

Industry comes from the SIC code on each company's own SEC filings, which is self-reported and sometimes out of date. Derivative exposure is counted with the shares. Securities the SEC assigns no industry - funds, trusts, foreign issues - are shown as not classified rather than dropped.

Biotech & Pharma 84.7%Healthcare Services 5.4%Medical Devices 3.9%Other sectors 0.5%Not classified 5.4%
 
SectorValueShare
Biotech & Pharma$1.8B84.7%
Healthcare Services$117.9M5.4%
Medical Devices$84.4M3.9%
Other sectors$11.4M0.5%
Not classified$118.1M5.4%

What the disclosed book did

This is not the fund's return. A 13F shows long US equity positions only, so shorts, bonds, foreign listings, private holdings and cash are all invisible here. What this measures is the quarter's change in value of the positions this manager disclosed, had they been left untouched - the return a reader following the filing would have earned.

QuarterBookMarket DifferencePriced
Q2 2026+12.0%+14.8%-2.8%98%
Q1 2026-3.8%-4.6%+0.9%100%
Q4 2025+24.8%+2.4%+22.4%100%
Q3 2025+25.5%+7.8%+17.6%100%
Q2 2025-3.1%+10.5%-13.6%99%
Q1 2025-7.3%-4.6%-2.8%99%
Q4 2024-8.8%+2.1%-11.0%100%
Q3 2024-1.3%+5.4%-6.8%95%

Market is SPY over the same two quarter ends, priced the same way as everything else here - the median across every filer reporting it. It is a large-cap US proxy, so a manager holding small caps or biotech will beat or trail it for reasons that are not skill. Prices are quarter-end to quarter-end and say nothing about the path in between, or about trades opened and closed inside a quarter.

Quarter by quarter

QuarterValuePositions NewAddedTrimmed ExitedTop 10 Days to file
Q2 2026$2.2B545490256.1%48
Q1 2026$653.9M5151717363.8%45
Q4 2025$718.4M4981211367.8%48
Q3 2025$540.4M4431319467.2%45
Q2 2025$470.0M457414675.2%45
Q1 2025$525.1M443910274.8%45
Q4 2024$645.4M432610476.6%45
Q3 2024$769.9M458710276.8%45
Q2 2024$863.0M39235180.4%45
Q1 2024$886.7M38669273.4%45
Q4 2023$1.1B34749281.3%46
Q3 2023$1.1B29044188.3%45
Q2 2023$1.2B30242287.1%45
Q1 2023$1.2B30242187.8%45
Q4 2022$1.2B291115489.3%45
Q3 2022$1.3B32115285.0%45
Q2 2022$1.1B33007282.8%46
Q1 2022$1.3B350715280.9%46
Q4 2021$1.6B37277777.8%45
Q3 2021$1.7B42153176.2%46
Q2 2021$1.8B42073074.0%47
Q1 2021$1.8B424187372.6%47
Q4 2020$1.9B414211676.4%47
Q3 2020$1.8B434256279.7%47
Q2 2020$1.7B416418275.8%45
Q1 2020$1.2B373219372.6%45
Q4 2019$1.8B372221268.8%99
Q3 2019$1.5B370023268.6%45
Q2 2019$2.1B39299068.6%45
Q1 2019$2.4B373141268.9%121
Q4 2018$1.9B36000070.8%45

Rows marked UNVERIFIED ID, PLACEHOLDER ID, TICKER AS ID or NON-CUSIP ID carry an identifier that is not a valid CUSIP. They are shown because the filer reported that money, but treat the security named with caution - hover the chip for what is wrong with it, and see the methodology.

Held counts consecutive filings in which this manager reported the position, and can reach further back than the quarters listed above: the tabs begin at Q4 2018 because earlier coverage is too sparse to describe a market, but tenure is counted over every filing we hold, some reaching to 2007. A position sold and later rebought starts again from one.

Weight change is the shift in this position's share of the whole book, in percentage points. It is the more useful column: when money flows into or out of a broad fund, almost every holding is bought or sold at once, so added and trimmed largely track flows. A weight that rose while the book shrank is a decision. Both compare with the previous quarter this filer reported, not the previous calendar quarter.