Go big or go home. Billionaire investor Bill Ackman of Pershing Square Capital Management takes that sentiment to heart. His hedge fund has some $13 billion in assets under management, but he owns just 10 stocks (track his portfolio here),

Bill Ackman is one of the most widely followed investment managers in the world. He's in charge of Pershing Square Capital, a hedge fund focused on investing in just a handful of Ackman's best ideas. His highly concentrated portfolio is full of great companies, but he might have just made one stock the biggest holding at Pershing Square.

Uber’s stock extends its surge as hedge funder Ackman says he’s amassed a 30.3-million-share stake since early January.

Last week, the stock of Uber Technologies went on a wild ride, falling hard after Uber reported earnings on Feb. 5, only to rocket higher toward the end of the week. On earnings, while revenue and earnings per share actually beat expectations,

Uber stock hit its highest level since October after Ackman disclosed his Pershing Square hedge fund accumulated a 1.4% stake in the ride hailer.

The Pershing Square CEO said he's admired the ridesharing giant since actor Edward Norton introduced him to the app in its early days.