Bill Ackman

Outspoken activist investor known for taking large stakes in companies and pushing for major changes to unlock value.

Bill Ackman founded Pershing Square Capital in 2004 after his previous fund Gotham Partners closed. He's famous for activist campaigns—taking 5-20% stakes in undervalued companies, then aggressively pushing management to make changes (spinoffs, buybacks, CEO replacement, asset sales). Major wins include Canadian Pacific Railway (quadrupled), General Growth Properties (10x return from bankruptcy), and his legendary COVID hedge in February 2020 that turned $27M into $2.6B in 30 days. However, Ackman has also had spectacular failures: his $1B short of Herbalife lost money for years, and his Valeant Pharmaceuticals investment cratered 90%. Known for his public battles, CNBC appearances, and 300-page investor presentations. His approach combines fundamental analysis with corporate activism and public advocacy.

Buy great businesses at good prices, then push management to unlock value. Public pressure can accelerate change.

Concentrated portfolio of 8-12 stocks. Deep fundamental analysis to identify mispriced businesses with hidden value. Build activist positions (5-20% ownership) to influence management. Push for operational improvements, capital allocation changes, board seats, or strategic alternatives. Very long holding periods (3-7 years) for winning positions.

1. 1. Activist Campaigns: Buy 5-20% stakes, push for board seats, CEO changes, strategic alternatives
2. 2. Concentrated Bets: 8-12 position portfolio, each position 10-15% of fund
3. 3. Public Advocacy: Use media, investor presentations, and letters to pressure management
4. 4. Special Situations: Target companies in distress, turnarounds, or with hidden value

• 16.5% annual returns since 2004 inception
• COVID hedge: 9,600% return in 1 month
• Canadian Pacific: 300%+ over 4 years
• Worst year: -20.5% in 2015 (Valeant disaster)

• Pershing Square investor letters ↗
• Ackman's Hell is Coming presentation (COVID) ↗