Billionaire Investor Battle: Comparing How Warren Buffett and Bill Ackman Invest

Core Viewpoint - Bill Ackman, CEO of Pershing Square Capital Management, is reportedly shifting his investment strategy towards building a "modern-day Berkshire Hathaway," indicating a potential change from his historically aggressive investment style [1] Group 1: Investment Strategies - Ackman and Buffett both utilize concentrated portfolios, allowing for larger bets on select companies due to their professional insights [3] - Buffett's portfolio is heavily concentrated, with three stocks—Apple, American Express, and Bank of America—making up nearly half of Berkshire Hathaway's $311 billion portfolio [4] - Ackman's Pershing Square also follows a concentrated approach, owning only 11 stocks, with its top three positions—Uber Technologies, Brookfield Corp., and Howard Hughes Holdings—comprising over half of its approximately $14.6 billion portfolio [5] Group 2: Investment Philosophy - Buffett is known for his buy-and-hold philosophy, favoring long-term investments over short-term market fluctuations [6] - Historically, Ackman's investment style was more activist and short-term, focusing on large positions in controversial companies for quick profits [7] - Ackman's recent shift towards long-term positions in durable companies suggests a significant change in his investment philosophy [7]