Yuri Milner

The Russian tycoon Yuri Milner wooed Zuckerberg in 2009 and made an investment that's already paid off big time. He's cashed out more than $1.7 billion at the IPO, and might be looking to shed some more, especially considering that two of his other big bets -- Zynga and Groupon -- are cratering. His investment firm, DST Global, still owns 80.6 million Class B shares, and 5 million Class A.