Eduardo Saverin: $5 Billion
Twenty-nine year old Eduardo Saverin was Facebook's chief financial officer and business manager when "thefacebook.com" first launched at Harvard University.
Saverin wasn't acknowledged as a cofounder until 2009 when he filed a lawsuit against Zuckerberg and Facebook. The lawsuit resulted in a settlement that named Saverin to the list of cofounders, plus a 5 percent stake in the company.
Today, Saverin's stake could translate to a $5 billion payday.