Accel Partners: $8 Billion
Accel Partners was one of Facebook's first investors, investing more than $12 million in the social network back in May 2005.
In a press release on the company's website, Accel Partners wrote, "It is not easy capturing the attention of Jim Breyer, one of Silicon Valley's leading venture capitalists. But Mark Zuckerberg, a 21-year-old Harvard student, managed to do it with a Web site that has attracted 2.8 million registered users on more than 800 campuses since it began in February 2004."
That $13 million investment is paying off huge: Accel Partners—and Jim Breyer (left)—could walk away with $8 billion.