Peter Thiel

Thiel made a big bet on Mark Zuckerberg in 2004 when he put $500,000 into Facebook, becoming one of the first outside investors in the social network. He cashed out $640 million in the IPO -- at a price more than 40 percent above where the stock trades now -- and it's never easy to sell a stock when it was worth so much more just a few months ago. We wouldn't expect him to immediately dump his holdings, but who knows. He could gradually start letting some go.