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Pershing Square
Bill Ackman runs Pershing Square as a concentrated, publicly listed activist fund, making large-cap bets from a permanent-capital base in New York.
Pershing Square
Pershing Square was founded in 2004 by Bill Ackman, who had previously co-founded Gotham Partners. The vehicle emerged from the dissolution of that earlier partnership, with a small pool of outside capital backing Ackman's conviction that deep fundamental research, paired with a willingness to publicly agitate for board seats and strategic changes, could unlock shareholder value in a handful of underperforming large-cap companies. The firm converted its main vehicle into Pershing Square Holdings, a closed-end fund listed on the Euronext Amsterdam and the London Stock Exchange, an intentional structural choice designed to eliminate redemption risk and allow the strategy to ride out the volatility inherent in its concentrated bets. The strategy is defined by extreme concentration. The portfolio typically holds eight to twelve core long equity positions, each subjected to months of private due diligence before a position is built, then defended in public white papers, conference calls, and SEC filings when the campaign escalates. Asset classes covered include publicly traded equities, with occasional use of credit default swaps and interest rate hedges as thematic expressions. Named positions confirmed in regulatory filings have included Chipotle Mexican Grill, Hilton Worldwide, Restaurant Brands International, Alphabet, and Howard Hughes Holdings. Ackman also famously deployed credit protection against monoline insurers during the 2007–2008 financial crisis. The geographic footprint is primarily North American large-cap equities, though the Euronext listing draws a European shareholder base. The firm operates with a lean senior team around Ackman. In September 2024, Ackman announced Pershing Square USA, a proposed US-listed closed-end fund targeting $25 billion, before withdrawing the offering weeks later amid reduced demand expectations. The episode drew widespread coverage from The Wall Street Journal and Reuters, who noted the unusual reversal underscored the gap between Ackman's social-media-driven profile and institutional order-book realities. Philanthropic activity runs through the Pershing Square Foundation, which Ackman co-manages and which has made nine-figure commitments to organizations including The Innocence Project and Teach For America. Pershing Square's structural differentiator is its permanent-capital base delivered through a European-listed closed-end fund. Unlike most activist managers who endure constant asset-liability matching pressure from quarterly redemption terms, Ackman's lock-up structure means he cannot be redeemed during a drawdown. That architecture permits the high-conviction, high-concentration bets that define the returns — but also forces the public market to price the strategy daily, making Pershing Square Holdings one of the most transparent experiments in activist investing ever conducted.
General information
Firm type
Asset Manager
Year founded
2004
AUM
$10B–$20B (Altss estimate)
Location
Region
North America
Country
United States
City
New York
Corporate office
New York, NY, United States
Principals
Bill Ackman
CEO and Portfolio Manager
Sector focus
Frequently asked questions
Who runs investment decisions at Pershing Square?
Bill Ackman, who founded the firm in 2004, is the CEO and Portfolio Manager and makes all binding investment decisions. He is supported by a small team of senior investment professionals, but the firm's public filings consistently identify him as the sole person responsible for the portfolio, and his public commentary drives the market narrative around every major position.
Is Pershing Square an asset manager or a family office?
Pershing Square operates as an asset manager. Its main vehicle, Pershing Square Holdings, is a publicly traded closed-end fund listed in Europe, holding third-party capital alongside Ackman's own. The firm also runs separate vehicles for US investors. The structure is deliberately permanent-capital, functioning like a publicly listed holding company rather than a traditional hedge fund with quarterly redemptions.
How concentrated is the Pershing Square portfolio?
Extremely concentrated. The portfolio typically holds between eight and twelve core long equity names at any given time, with the top five positions commonly exceeding 60% of assets. This concentration is a stated feature of the strategy, not a byproduct of limited resources; it reflects Bill Ackman's conviction that deep fundamental research into a handful of companies yields higher risk-adjusted returns than diversification.
Does Pershing Square use the activist playbook on every investment?
No. While the firm's most visible investments involve proxy fights and public campaigns — Chipotle Mexican Grill's turnaround and the Canadian Pacific proxy contest being prominent examples — many positions are built quietly. Ackman has described the approach as 'friendly activist when possible, confrontational when required,' and his research-heavy public presentations often function as the first move in an activist engagement rather than a recurring tactic.
What happened to Pershing Square's plan to launch a US-listed fund?
In September 2024, Ackman filed for a proposed US-listed closed-end fund, Pershing Square USA, initially targeting $25 billion in assets. Weeks later, he withdrew the offering after reducing the target to roughly $2 billion, signaling that institutional demand did not match his publicly stated expectations. The reversal was documented by Reuters and The Wall Street Journal as an unusual public retreat for a manager with a large social-media following.
How does Ackman use public communication to support his investment strategy?
Ackman publishes institutional-quality research presentations on the firm's website, hosts lengthy public conference calls with Q&A, and maintains an active presence on X (formerly Twitter). This transparency is not marketing veneer — it directly supports the firm's activist strategy by shaping public and shareholder opinion ahead of votes or management negotiations, a tactic that was most visible during the Allergan campaign and the fight over Herbalife.
What is the Pershing Square Foundation, and is it related to the investment firm?
The Pershing Square Foundation is a separate philanthropic entity co-managed by Bill Ackman and his wife, Neri Oxman. It operates independently of the investment entity but shares the name and is funded by Ackman's personal capital. The foundation has made significant gifts to organizations including The Innocence Project, Teach For America, and the Human Vaccines Project, and the separation between foundation governance and fund governance is maintained through distinct boards.
Profile maintained by Altss using OSINT (open-source intelligence), regulatory filings, licensed data partners, and verified direct submissions. Read the methodology. Last updated: . Continuous refresh with full update cycles at least every 30 days.
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