The hedge fund manager is picky about which stocks he buys, but these two passed the test for him in Q2.Bill Ackman ranks among the most successful investors on the planet. Thanks to the tremendous success of his Pershing Square Capital Management hedge fund, Ackman's net worth currently totals close to $9 billion. But the billionaire isn't a big fan of diversification. Pershing Square's portfolio includes only nine stocks. And two of them were added in the second quarter of 2024. Here's why Ackman bought$ ...