Billionaire investor Bill Ackman has made a hefty investment in Amazon.com Inc. (NASDAQ:AMZN), pouring in more than $1.27 billion within a span of three months.What Happened: Ackman’s firm, Pershing Square Capital Management, accumulated 5,823,316 shares of Amazon, which accounts for nearly 10% of the firm's $13.7 billion total assets under management, as revealed in the latest 13F filing with the U.S. Securities and Exchange Commission (SEC).Not stopping at Amazon, Pershing also ramped up its holdings in Alphabet Inc. (NASDAQ:GOOGL) by 925,000 shares, taking ...Full story available on Benzinga.com