Core Insights - Billionaire Bill Ackman's Pershing Square Capital Management hedge fund has significantly outperformed the S&P 500 in 2025, achieving a 22.9% increase compared to the index's 10.8% gain as of the end of August [1] Group 1: Investment Strategy - Ackman's outperformance is attributed to capitalizing on market inefficiencies by investing in undervalued stocks, maintaining a concentrated portfolio with long-term holdings [2] - The hedge fund's transparency through social media and investor calls allows average investors to follow Ackman's investment decisions [2] Group 2: Recent Investments - In May, Pershing Square disclosed the acquisition of another stock from the "Magnificent Seven," adding to its existing significant position in Alphabet (NASDAQ: GOOG) [3] - Ackman took advantage of market volatility caused by tariff announcements to purchase Amazon (NASDAQ: AMZN) shares, which had declined due to fears of negative impacts on its retail and cloud computing businesses [5][6] Group 3: Valuation and Growth Potential - Ackman purchased Amazon shares at 25 times forward earnings estimates, expressing confidence in the stock's value despite market uncertainties [6] - He believes that Amazon's share price still has substantial upside potential due to its ability to sustain high earnings growth over the long term [6][7]