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July 27, 2026Short & citedBlog
Civic Viewpoint.
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Money & Work • Investor

Bill Ackman

Bill Ackman is an American billionaire hedge fund manager and activist investor.

Updated July 27, 20261 min readCited sources

Bill Ackman is an American billionaire hedge fund manager and activist investor. He is the founder and chief executive of Pershing Square Capital Management.

What it is

Bill Ackman founded Pershing Square Capital Management in 2004 and serves as its CEO. The firm is known for a concentrated investment approach, taking large stakes in a small number of high-quality, cash-generative businesses. Ackman is widely described as an activist investor, pushing for strategic changes at the companies he invests in.

Why it matters

Ackman gained prominence through high-profile activist campaigns involving companies like Herbalife, Chipotle, Canadian Pacific Railway, and General Growth Properties. His public commentary on politics, universities, and social issues has also drawn significant attention. Pershing Square's concentrated bets can influence entire sectors.

Key details

Bloomberg estimated Ackman's net worth at about US$8 billion in April 2026. He has been critical of Harvard and other institutions in 2023-2024. For Canadian readers, Pershing Square's involvement with Canadian Pacific Railway is a notable local connection.

In short

  • Founder and CEO of Pershing Square Capital Management.
  • Known for activist, concentrated investing.
  • Net worth estimated at US$8 billion (April 2026).
  • Canadian connection: investment in Canadian Pacific Railway.
Canadian angle

Ackman is relevant to Canadian readers because Pershing Square has been associated with major Canadian investments and activism, including Canadian Pacific Railway.[8][12]

Quick questions

Who is Bill Ackman?
Bill Ackman is an American billionaire hedge fund manager and activist investor, founder and CEO of Pershing Square Capital Management.
What is Bill Ackman's net worth?
Bloomberg estimated his net worth at about US$8 billion in April 2026.
What is his investment strategy?
Ackman uses an activist, concentrated approach, taking large stakes in a few public companies and engaging for long-term value creation.

Sources

  1. Wikipedia — https://en.wikipedia.org/wiki/Bill_Ackman
    Supports: Basic biographical details, founding of Pershing Square, activist investor description, and Bloomberg net worth estimate.
  2. Encyclopaedia Britannica — https://www.britannica.com/money/Bill-Ackman
    Supports: Biography, role as founder and CEO of Pershing Square, activist investor profile, and public prominence.
  3. Pershing Square Philanthropies — https://pershingsquarephilanthropies.org/people/bill-ackman
    Supports: Ackman as CEO of Pershing Square, founding year, concentrated investment approach, and active engagement with portfolio companies.
  4. Fortune — https://fortune.com/ranking/most-powerful-people/2025/bill-ackman/
    Supports: Pershing Square assets, activist reputation, prominent influence, and Canadian Pacific Railway as a notable investment.
  5. CNBC — https://www.cnbc.com/bill-ackman/
    Supports: Founding of Pershing Square and notoriety for activist initiatives involving companies such as General Growth Properties and Herbalife.
  6. Bloomberg — https://www.bloomberg.com/features/2025-bill-ackman-tweeting-through-it/
    Supports: Description of Ackman as an activist investor and context for his public profile.
  7. Vox — https://www.vox.com/2024/1/13/24032176/bill-ackman-claudine-gay-harvard-plagiarism-business-insider-explained
    Supports: General background on his public attention, activist investing reputation, and examples of companies involved in his investing history.