Palo Alto Investors Lp (CIK: 0001306923) is a financial institution headquartered at 101 University Ave, Suite 200, Palo Alto, California 94301. The firm regularly files Form 13F with the U.S. Securities and Exchange Commission (SEC), disclosing its equity holdings and investment positions.

As of the latest reporting period (2026-03-31), the institution manages a portfolio valued at $653.86 M, comprising 51 distinct securities. Over its filing history, it has submitted 58 Form 13F reports.

To view the institution’s full SEC filing history:
🔗 View All SEC Filings

Q1 2026 — Top-10 concentration: 63.9%. Quarterly turnover: 10.2%. ▲ 5 new, +17 added, −17 reduced, ×3 exited.

Top Buys

Q1 2026

1. MIRM Mirum Pharmaceuticals

+$15.59 M

2. CLDX Celldex Therapeutics

+$9.4 M

3. ACAD Acadia Pharmaceuticals

+$8.65 M

4. IRON Disc Medicine

+$5.39 M

5. BCAX Bicara Therapeutics

+$5.01 M

Top Sells

Q1 2026

1. FOLD Amicus Therapeutics

−$59.18 M

2. GOSS Gossamer Bio

−$13.86 M

3. INSM Insmed Incorporated

−$12.14 M

4. BIIB Biogen

−$7.86 M

5. DNLI Denali Therapeutics

−$7.81 M

Stocks/ETFs

-8.98%

$653.86 M 100.00%

Options

$0 0.00%

Debt

$0 0.00%

Other

$0 0.00%

Name	Shares	Market Value	Weight	Change	Activity
Insmed Incorporated INSM	415,269	$67.9 M	10.39%	▼ 74,213	Reduce -15.2%
Acadia Pharmaceuticals ACAD	2.87 M	$63.95 M	9.78%	▲ 388,664	Add 15.7%
Ptc Therapeutics PTCT	921,607	$62.79 M	9.60%	▲ 17,691	Add 2.0%
Biomarin Pharmaceutical BMRN	685,182	$38.71 M	5.92%	▼ 61,074	Reduce -8.2%
United Therapeutics Corporation UTHR	62,809	$37.24 M	5.70%	▲ 4,623	Add 8.0%
Anaptysbio ANAB	638,161	$35.39 M	5.41%	▼ 51,871	Reduce -7.5%
Mirum Pharmaceuticals MIRM	325,175	$30.04 M	4.59%	▲ 168,754	Add 107.9%
Dyne Therapeutics DYN	1.65 M	$29.97 M	4.58%	▲ 180,775	Add 12.3%
Biogen BIIB	140,719	$25.8 M	3.95%	▼ 42,852	Reduce -23.3%
Disc Medicine IRON	401,719	$25.69 M	3.93%	▲ 84,263	Add 26.5%

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Palo Alto Investors Lp's Portfolio

This portfolio view aggregates one or more SEC Form 13F filings submitted by Palo Alto Investors Lp each quarter. Holdings are organized into Stocks/ETFs, Options, Debt, and Other, with transaction markers indicating New Buy, Add, Reduce, No Change, or Sold Out. Reported anomalies are corrected where possible, and share counts are adjusted to reflect corporate actions such as stock splits. Since 2013, we have collected 52 quarters of portfolio data for this firm, providing a transparent record of institutional strategy over time.

Options Exposure History

CALL PUT

Report Date	Type	Underlying Shares	Notional Value	% Change

Report Date	Bought/Sold (Sh.)	% Change	Qtr. End Shares	Reported Price

Stocks ETFs

Name	Shares	Value	% of Portfolio	% Change
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CALL PUT

Type	Name	Shares	Value	% of Portfolio	% Change
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Name	Amount	Value	% of Portfolio	% Change
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Palo Alto Investors Lp Quarterly 13F Statistics

Discover detailed insights into Palo Alto Investors Lp’s SEC Form 13F filings, including:

Quarterly changes in holdings
Portfolio turnover
Asset allocation trends
Top 10 stock and ETF positions

This page provides a transparent view of institutional strategies based on official SEC disclosures, helping investors track long‑term shifts since 2013.

Quarter	Holdings	Total Value	Turnover Rate	Asset Allocation	Top 10 Stock & ETF Holdings

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Palo Alto Investors Lp's All 13F Filings

This section lists all SEC Form 13F filings submitted by Palo Alto Investors Lp.

Form 13F must be filed within 45 days after the end of each calendar quarter and discloses the reporting manager, the securities held, their CUSIP numbers, the number of shares held at quarter-end, and the total reported market value.

Please note that the market value shown reflects reported holdings only and should not be considered a substitute for Assets Under Management (AUM), as cash positions are excluded.
Each filing entry includes a direct link to the original Form 13F document on the SEC’s EDGAR system .

Report For	Filed At	AUM	Holdings	Form Type	Source

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Insider Trading Activity (SEC Form 4)

This section tracks real-time insider transactions reported via SEC Form 4 filings. Unlike the quarterly 13F portfolio snapshots, these records reflect immediate buying and selling activity where the filer acts as a corporate insider. Use this data to spot timely market moves.

Date Top Line (Transaction Date): The date of the most recent insider transaction. Bottom Line (Filing Date): The date the transaction was filed with the SEC.	Value Total Value: The total monetary value of the transaction. (Shares × Price)	Shares Shares Traded: Number of shares bought or sold in this specific transaction. Adjusted for splits.	Position / Chg Top Line (Held): Total shares owned after the transaction. Bottom Line (Change %): The percentage change in holdings due to this trade.
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Data Source & Methodology: This table is sourced exclusively from SEC Form 4 filings and is adjusted for stock splits. It reflects active insider trading decisions and does not include passive beneficial ownership reported in 13F or 13D/G filings.

Palo Alto Investors Lp 13F Filings, Portfolio & Analysis

Palo Alto Investors Lp — Portfolio Overview & Company Profile

Portfolio Summary (Q1 2026)

Top Buys

Top Sells

Asset Allocation

Sector Allocation (Stocks)

Top Stock & ETF Holdings (Q1 2026)

Historical Portfolio Charts

Palo Alto Investors Lp's Portfolio

Palo Alto Investors Lp Quarterly 13F Statistics

Palo Alto Investors Lp's All 13F Filings

Insider Trading Activity (SEC Form 4)