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Palo Alto Investors LP Palo Alto Investors

Palo Alto, CA 23 processed 13Fs on this site, 2021 Q3 to 2026 Q2

  • $724M
  • 52 holdings
  • 2026 Q2
  • +10.7% QoQ
  • Top 5 37.7%

Portfolio

2026 Q2, filed 8/19/2026, top 12 of 52 holdings

Top 5 37.7%, top 10 61.3%

  1. PTC, PTC Therapeutics 10.4%
  2. ACAD, Acadia Pharmaceuticals 10.0%
  3. INSM, Insmed 6.1%
  4. MIRM, Mirum Pharmaceuticals 5.6%
  5. ANAB, Anaptysbio 5.6%
  6. BMRN, Biomarin Pharmaceutical 5.4%
  7. DYN, Dyne Therapeutics 5.1%
  8. UTHR, United Therapeutics 4.7%
  9. IRON, Disc Medicine 4.2%
  10. BIIB, Biogen 4.2%
  11. IOVA, Iovance Biotherapeutics 3.0%
  12. RARE 2.8%
  13. Other 32.9%

AUM over time

2026 Q2 $724M +10.7% QoQ
2021 Q3: $1.7B 2021 Q3: $1.7B
Q3 2021
2021 Q4: $1.6B, −5.6% QoQ 2021 Q4: $1.6B, −5.6% QoQ
Q4
2022 Q1: $1.3B, −17.4% QoQ 2022 Q1: $1.3B, −17.4% QoQ
Q1 2022
2022 Q2: $1.1B, −11.3% QoQ 2022 Q2: $1.1B, −11.3% QoQ
Q2
2022 Q3: $1.3B, +10.3% QoQ 2022 Q3: $1.3B, +10.3% QoQ
Q3
2022 Q4: $1.2B, −7.3% QoQ 2022 Q4: $1.2B, −7.3% QoQ
Q4
2023 Q1: $1.2B, +2.9% QoQ 2023 Q1: $1.2B, +2.9% QoQ
Q1 2023
2023 Q2: $1.2B, +2.6% QoQ 2023 Q2: $1.2B, +2.6% QoQ
Q2
2023 Q3: $1.1B, −14.6% QoQ 2023 Q3: $1.1B, −14.6% QoQ
Q3
2023 Q4: $1.1B, +4.7% QoQ 2023 Q4: $1.1B, +4.7% QoQ
Q4
2024 Q1: $887M, −19.9% QoQ 2024 Q1: $887M, −19.9% QoQ
Q1 2024
2024 Q2: $863M, −2.7% QoQ 2024 Q2: $863M, −2.7% QoQ
Q2
2024 Q3: $770M, −10.8% QoQ 2024 Q3: $770M, −10.8% QoQ
Q3
2024 Q4: $645M, −16.2% QoQ 2024 Q4: $645M, −16.2% QoQ
Q4
2025 Q1: $525M, −18.6% QoQ 2025 Q1: $525M, −18.6% QoQ
Q1 2025
2025 Q2: $470M, −10.5% QoQ 2025 Q2: $470M, −10.5% QoQ
Q2
2025 Q3: $540M, +14.9% QoQ 2025 Q3: $540M, +14.9% QoQ
Q3
2025 Q4: $718M, +33.0% QoQ 2025 Q4: $718M, +33.0% QoQ
Q4
2026 Q1: $654M, −8.9% QoQ 2026 Q1: $654M, −8.9% QoQ
Q1 2026
2026 Q2: $724M, +10.7% QoQ 2026 Q2: $724M, +10.7% QoQ
Q2

Book

2026 Q1 2025 Q4, filed 15 May, long equity only

Download CSV Download Excel All activity
INSM, Insmed 10.39%, was 11.86% Reduce −15.2% 415,269 $163.52 $68M −74,213 −$17M
ACAD, Acadia Pharmaceuticals 9.78%, was 9.24% Add +15.6% 2,872,695 $22.26 $64M +388,664 −$2.4M
PTC, PTC Therapeutics 9.60%, was 9.56% Add +2.0% 921,607 $68.13 $63M +17,691 −$5.9M
BMRN, Biomarin Pharmaceutical 5.92%, was 6.17% Reduce −8.2% 685,182 $56.49 $39M −61,074 −$5.6M
UTHR, United Therapeutics 5.70%, was 3.95% Add +7.9% 62,809 $592.98 $37M +4,623 +$8.9M
ANAB, Anaptysbio 5.41% Reduce −7.5% 638,161 $55.46 $35M −51,871 +$1.9M
MIRM, Mirum Pharmaceuticals 4.59%, was 1.72% Add +107.9% 325,175 $92.38 $30M +168,754 +$18M
DYN, Dyne Therapeutics 4.58%, was 4.01% Add +12.3% 1,652,972 $18.13 $30M +180,775 +$1.2M
BIIB, Biogen 3.95%, was 4.50% Reduce −23.3% 140,719 $183.33 $26M −42,852 −$6.5M
IRON, Disc Medicine 3.93%, was 3.51% Add +26.5% 401,719 $63.94 $26M +84,263 +$477K
IOVA, Iovance Biotherapeutics 3.41% Reduce −10.8% 6,349,563 $3.51 $22M −767,113 +$2.9M
SNDX, Syndax Pharmaceuticals 3.09%, was 2.32% Add +8.9% 864,986 $23.36 $20M +70,479 +$3.5M
ANNX, Annexon 2.50%, was 1.67% Add +23.7% 2,948,090 $5.54 $16M +563,898 +$4.4M
FOLD, Amicus 2.46%, was 10.32% Reduce −78.6% 1,113,045 $14.46 $16M −4,092,722 −$58M
NVCR, Novocure 2.13%, was 2.34% Reduce −1.4% 1,280,439 $10.90 $14M −18,525 −$2.8M
RARE 1.91%, was 1.48% Add +29.3% 596,495 $20.95 $12M +135,201 +$1.9M
PRTA, Prothena 1.80% Reduce −8.5% 1,208,568 $9.72 $12M −111,942 −$864K
BCAX, Bicara Therapeutics 1.67%, was 0.70% Add +84.3% 550,408 $19.89 $11M +251,833 +$5.9M
CLDX, Celldex Therapeutics 1.44% New 296,408 $31.72 $9.4M +296,408 +$9.4M
CDNA, Caredx 1.41%, was 1.25% Add +11.2% 531,870 $17.36 $9.2M +53,650 +$224K
ALKS, Alkermes 1.31% Hold 242,560 $35.36 $8.6M — —
CMPX, Compass Therapeutics 1.23%, was 1.89% Reduce −40.2% 1,514,504 $5.29 $8M −1,017,915 −$5.6M
AGIO, Agios Pharmaceuticals 1.11%, was 0.81% Add +0.5% 213,601 $33.83 $7.2M +1,102 +$1.4M
ALGN, Align Technology 1.09% Hold 41,520 $171.43 $7.1M — —
CAPR 1.07%, was 0.91% Add +1.5% 229,763 $30.40 $7M +3,459 +$454K
TVTX, Travere Therapeutics 1.05%, was 0.59% Add +108.1% 230,453 $29.71 $6.8M +119,734 +$2.6M
TSHA, Taysha Gene Therapies 0.95%, was 0.91% Add +17.6% 1,391,382 $4.47 $6.2M +208,187 −$288K
ACRS, Aclaris Therapeutics 0.93%, was 0.66% Add +3.0% 1,613,430 $3.75 $6.1M +46,590 +$1.3M
DNLI, Denali Therapeutics 0.69%, was 1.47% Reduce −63.4% 234,582 $19.20 $4.5M −406,657 −$6.1M
XENE, Xenon Pharmaceuticals 0.46%, was 0.60% Reduce −46.8% 51,345 $58.15 $3M −45,174 −$1.3M
ORKA, Oruka Therapeutics 0.45% Hold 59,985 $49.05 $2.9M — —
STOK, Stoke Therapeutics 0.42%, was 0.32% Add +17.5% 84,631 $32.56 $2.8M +12,609 +$470K
EW, Edwards Lifesciences 0.41% Hold 33,640 $80.08 $2.7M — —
NBIX, Neurocrine Biosciences 0.37% Hold 18,117 $131.74 $2.4M — —
NUVB, Nuvation Bio 0.33%, was 0.67% Reduce −5.4% 508,846 $4.29 $2.2M −29,233 −$2.6M
CYTK, Cytokinetics 0.32% New 32,195 $65.91 $2.1M +32,195 +$2.1M
EHTH, Ehealth 0.29%, was 0.98% Reduce −3.2% 1,482,797 $1.29 $1.9M −48,632 −$5.1M
CRSP, Crispr Therapeutics 0.29%, was 0.30% Reduce −3.9% 39,605 $47.57 $1.9M −1,621 −$278K
BNTX, Biontech Se-Adr 0.27% Hold 19,614 $88.88 $1.7M — —
PYXS, Pyxis Oncology 0.23% Reduce −2.6% 1,010,510 $1.46 $1.5M −26,911 +$282K
VSTM, Verastem 0.20% New 246,093 $5.30 $1.3M +246,093 +$1.3M
BCYC 0.14%, was 0.22% Reduce −8.7% 201,890 $4.64 $937K −19,181 −$628K
MDGL, Madrigal Pharmaceuticals 0.14% New 1,787 $523.47 $935K +1,787 +$935K
HUM, Humana 0.11% Hold 3,985 $173.39 $691K — —
CMPS, Compass Pathways 0.10% Hold 115,616 $5.53 $639K — —
XERS, Xeris Biopharma 0.09% New 104,410 $5.80 $606K +104,410 +$606K
ABEO, Abeona Therapeutics 0.07% Hold 108,865 $4.48 $488K — —
INSP, Inspire Medical Systems 0.07% Hold 8,772 $51.58 $452K — —
URGN, Urogen 0.07% Hold 24,500 $17.98 $441K — —
PRQR, Proqr Therapeutics 0.05% Hold 188,807 $1.62 $306K — —

Showing top 50 of 51 by value

Exits / last held

Gone since 2025 Q4, shown at their last reported size.

Stock % of portfolio Recent activity Shares Reported price* Value Share change $ change
Gossamer Bio 1.93% Exit 0 $3.10 $14M −4,471,592 −$14M
Generation Bio 0.01% Exit 0 $5.65 $85K −15,047 −$85K
Akari Therapeutics Plc-Adr 0.01% Exit 0 $0.2876 $42K −146,024 −$42K

Weight bar: held both quarters added sold at this quarter’s reported price

* Reported price is value ÷ shares from the 13F as of period end, not a live market quote. Weight % is each long-equity position ÷ full 13F AUM, so rows may not sum to 100% when the filing includes options or other non-equity (excluded from this table). Share change and $ change are vs 2025 Q4. Click a column header to sort, or New, Hold, Add or Reduce to bring those moves to the top. Exit opens the last-held block below.

Filings history

20 periods, with AUM normalized

Newest 13Fs
Period Holds AUM QoQ Form Filed Filing ID
2026 Q2 52 $724M +10.7% RESTATEMENT 8/19/2026 000207367926000102
2026 Q2 52 $724M — RESTATEMENT 8/18/2026 000207367926000101
2026 Q2 52 $724M — 13F-HR 8/17/2026 000207367926000096
2026 Q1 51 $654M −8.9% 13F-HR 5/15/2026 000130692326000004
2025 Q4 49 $718M +33.0% 13F-HR 2/17/2026 000130692326000002
2025 Q3 44 $540M +14.9% 13F-HR 11/14/2025 000130692325000019
2025 Q2 45 $470M −10.5% 13F-HR 8/14/2025 000130692325000016
2025 Q1 44 $525M −18.6% 13F-HR 5/15/2025 000130692325000014
2024 Q4 43 $645M −16.2% 13F-HR 2/14/2025 000130692325000010
2024 Q3 45 $770M −10.8% 13F-HR 11/14/2024 000130692324000012
2024 Q2 39 $863M −2.7% 13F-HR 8/14/2024 000130692324000010
2024 Q1 38 $887M −19.9% 13F-HR 5/15/2024 000130692324000008
2023 Q4 34 $1.1B — RESTATEMENT 2/15/2024 000130692324000007
2023 Q4 34 $1.1B +4.7% 13F-HR 2/14/2024 000130692324000002
2023 Q3 29 $1.1B −14.6% 13F-HR 11/14/2023 000130692323000014
2023 Q2 30 $1.2B +2.6% 13F-HR 8/14/2023 000130692323000012
2023 Q1 30 $1.2B +2.9% 13F-HR 5/15/2023 000130692323000011
2022 Q4 29 $1.2B −7.3% 13F-HR 2/14/2023 000130692323000009
2022 Q3 32 $1.3B +10.3% 13F-HR 11/14/2022 000130692322000016
2022 Q2 33 $1.1B −11.3% 13F-HR 8/15/2022 000130692322000015
2022 Q1 35 $1.3B −17.4% 13F-HR 5/16/2022 000130692322000014
2021 Q4 37 $1.6B −5.6% 13F-HR 2/14/2022 000130692322000004
2021 Q3 42 $1.7B — 13F-HR 11/15/2021 000130692321000026

About

Palo Alto Investors LP

23 processed 13Fs on this site, 2021 Q3 to 2026 Q2

Entity
Palo Alto Investors LP
Notable person
Palo Alto Investors
Location
Palo Alto, CA
All SEC filings
View on sec.gov