Bill Ackman's Companies & Ventures

Bill Ackman's investment career has been defined by bold, concentrated bets and activist campaigns that have reshaped companies across industries.

Pershing Square Capital Management, founded in 2004, is his flagship hedge fund managing over $16 billion with a strategy focused on taking 10-15 large positions in high-quality businesses and engaging actively with management.

Pershing Square Holdings, listed on Euronext Amsterdam since 2014, is a closed-end fund that mirrors the hedge fund's portfolio and provides permanent capital — a structure that proved crucial when the Valeant investment went wrong, as it prevented forced redemptions.

Ackman's activist campaigns have transformed companies like Canadian Pacific Railway, where he replaced the CEO and board, driving a dramatic operational turnaround. His investment in Chipotle Mexican Grill after its E. coli crisis helped install new leadership that rebuilt the brand into one of the best-performing restaurant stocks of the decade.

His investment approach combines deep fundamental research with a willingness to engage publicly and push for change, making him one of the most influential activist investors in the world.