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Bill Ackman
United States
Net Worth
$9.5B
Source of Wealth
Hedge Funds
Global Rank
#101 of 102
About Bill Ackman
William Albert Ackman is the founder and CEO of Pershing Square Capital Management, a hedge fund known for concentrated, activist investments. Born in New York City in 1966, Ackman graduated from Harvard Business School and launched his career with an early fund, Gotham Partners, before founding Pershing Square in 2004.
Ackman is famous for his bold, public investment theses — including a highly profitable bet against the municipal bond insurer MBIA and a massive short position against Herbalife. He made one of the greatest trades in history by purchasing credit default swaps before the COVID-19 crash in March 2020, turning $27 million into $2.6 billion in roughly three weeks.
He is also known for his activist campaigns at companies like Canadian Pacific Railway, Wendy's, Target, and J.C. Penney — with results ranging from spectacular successes to costly failures. His transparency and willingness to engage publicly on X (Twitter) have made him one of the most recognizable hedge fund managers in the world.
Key Achievements
COVID Hedge: $27M to $2.6B
Purchased credit default swaps in February 2020 that turned $27 million into approximately $2.6 billion during the March 2020 market crash — one of the greatest single trades in history.
Canadian Pacific Railway Turnaround
Led an activist campaign at Canadian Pacific Railway in 2012 that replaced the CEO and board, transforming it into one of North America's best-performing railroads and generating billions in returns.
Founded Pershing Square Capital Management
Built Pershing Square from scratch in 2004 into one of the world's most prominent activist hedge funds, managing over $16 billion in assets.
Pershing Square Holdings IPO
Listed Pershing Square Holdings on the Euronext Amsterdam in 2014, creating permanent capital that survived the Valeant downturn without forced redemptions.
Chipotle Investment
Invested in Chipotle Mexican Grill after the E. coli crisis in 2016, helped install new management, and saw the stock price more than quadruple.
Notable Quotes
“I am a long-term, concentrated, research-intensive investor.”
— Bill Ackman
“The key to investing is not assessing how much an industry is going to affect society, or how much it will grow, but rather determining the competitive advantage of any given company and the durability of that advantage.”
— Bill Ackman
“I think the secret to investing is to be a learning machine.”
— Bill Ackman
“Risk is not the same as volatility. Risk is the permanent loss of capital.”
— Bill Ackman
“Transparency is the best form of regulation.”
— Bill Ackman
Key Decisions
Graduated from Harvard Business School and co-founded Gotham Partners with fellow Harvard grad David Berkowitz.
Published 'Is MBIA Triple A?' — a detailed public short thesis against the bond insurer that proved prescient during the financial crisis.
Wound down Gotham Partners after a bitter dispute with regulators and investors, a humbling experience that shaped his future approach.
Founded Pershing Square Capital Management with a focus on concentrated activist investing.
Launched activist campaign at Canadian Pacific Railway, ultimately replacing CEO and board, leading to massive stock appreciation.
Initiated a $1 billion short position against Herbalife, sparking a years-long public battle with Carl Icahn.
Listed Pershing Square Holdings on Euronext Amsterdam, creating permanent capital vehicle.
Made a large investment in Valeant Pharmaceuticals that would become a costly lesson when the stock collapsed.
Invested in Chipotle Mexican Grill during its E. coli crisis, helping drive a management transformation.
Executed the legendary COVID hedge — $27 million in credit default swaps turned into $2.6 billion in approximately three weeks.
Became one of the most influential voices on X (Twitter), engaging directly on politics, markets, and policy with millions of followers.
Early Life
Born in Chappaqua, New York, Ackman grew up in a middle-class family. His father, Lawrence Ackman, was the chairman of a real estate finance firm. Ackman attended Harvard College and then Harvard Business School. He co-founded Gotham Partners in 1992, his first hedge fund, which he wound down in 2003 after regulatory and performance challenges.
Companies & Ventures
Pershing Square Capital Management
$16B+ AUMFounder & CEO · Est. 2004
Activist hedge fund managing over $16 billion with a concentrated portfolio strategy. Known for taking large positions and working with management to improve operations.
Pershing Square Holdings
Chairman · Est. 2014
Publicly listed closed-end fund on Euronext Amsterdam that mirrors the hedge fund's portfolio, providing permanent capital without redemption pressure.
Portfolio & Holdings
Notable public equity positions associated with Bill Ackman.
HHH
Howard Hughes Holdings
QSR
Restaurant Brands International
CMG
Chipotle Mexican Grill
HLT
Hilton Worldwide
CP
Canadian Pacific Kansas City
GOOG
Alphabet
BN
Brookfield Corporation
MNST
Monster Beverage
Investment Principles
Concentration Over Diversification
Focus on 10-15 high-conviction positions rather than spreading across dozens of names. Deep research enables high-confidence bets.
Activist Engagement
Take meaningful ownership stakes and actively engage with management and boards to unlock value and drive operational improvements.
Simple, Predictable Businesses
Invest in businesses with durable competitive advantages, predictable cash flows, and limited exposure to technological disruption.
Asymmetric Risk-Reward
Seek investments where the downside is limited but the upside is multiples of the investment. The COVID hedge exemplified this principle perfectly.
Learn from Mistakes Publicly
Acknowledge errors transparently. The Valeant and Herbalife experiences made Pershing Square a better investor.
Life Lessons & Insights
Resilience After Public Failure
The Gotham Partners wind-down and the Valeant collapse were devastating setbacks, but Ackman rebuilt each time by learning and adapting.
Conviction Requires Courage
Going public with an investment thesis invites criticism and short-term pain, but transparency creates accountability that drives better outcomes.
One Great Trade Can Change Everything
The COVID hedge proved that a single asymmetric bet, properly sized and timed, can generate generational returns.
Know When to Walk Away
Exiting Herbalife and Valeant required acknowledging mistakes. The best investors cut losses rather than doubling down on broken theses.
Philanthropy
Ackman has signed the Giving Pledge, committing to give away the majority of his wealth. He has donated hundreds of millions to education, arts, and social causes, including major gifts to his alma mater Harvard and to organizations focused on homelessness and affordable housing.
Deep Dives
Go deeper into what makes Bill Ackman exceptional.
Explore More
See how Glen Bradford applies these principles to his own investing. Long Fannie Mae & Freddie Mac junior preferred — and not going anywhere.