One of the most prominent members of Silicon Valley’s PayPal mafia (a group of savvy entrepreneurs who emerged from the online payment firm), Thiel has invested in some of the hottest startups through The Founders Fund. Thiel started the venture capital fund, adapting to Web 2.0 entrepreneurs who don’t need much money to get off the ground and don’t want to give up big chunks of their companies. Thiel’s investments include Facebook, Slide, and Yammer. Still, Thiel does much more than focus on startups. After selling PayPal to eBay, Thiel left to found Clarium Capital Management, a global macro hedge fund that now manages more than $7 billion in investments.