Who he is: Eduardo P. Saverin  is a Brazil-born "internet entrepreneur  and investor," from a wealthy family that moved to Florida when it was discovered Eduardo's name was on a kidnap-for-ransom hit list--he now lives in Singapore. A classmate of Mark Zuckerberg's, Saverin actually finished his degree, earning a Bachelor of Economics. That didn't fare him too well in Facebook business machinations, as an increasingly wide split with Zuckerberg over the years ended in a court case that was settled out of court. Since then he's been putting his economic skills to use to take an active role in secondary market trading of Facebook stock. Now 29, he's a little camera-shy (we nearly had to use his schoolboy photo here, from his Facebook page) but he's reportedly enjoying his money, with the Daily Mail noting  he is "living it up" and last year was "cavorting with a clutch of bronzed beauties" in France. But he's also spending his money on investments: Social net Qwiki  and mobile payment site Jumio being notable targets (the latter just landing  $25.5 million in funding). He "didn't learn anything  from The Social Network."
His connection to Facebook: He was in on it early, when it was still The Facebook, and worked closely with Zuckerberg to launch it in 2004, holding early titles of CFO and the (slightly more hazily defined) business manager. As that famous film tells us, it all went nasty, and now he simply retains a stake in the company.
What he's worth already: Estimates  are up to $2 billion, but of course the figure varies as the net worth of the companies he's invested in changes, and dependent on how much secondary market trading he actually got up to before Facebook's IPO began.
How much he could make in the IPO: His settlement with Facebook resulted in him keeping a 5% share, but he's said  to have sold it down to 2.5%. At an $85 billion IPO value, that equates to $2.1 billion.
What he might do with the cash: That Mail story notes he blew $50,000 on champagne in a party session, so maybe he's taking a leaf out of Sean Parker's book. We can probably expect to see a few more tabloid-pleasing antics (All that money! All those beaches and models!), and possibly more investments along the lines of Qwiki and ShopSavvy , and you could be forgiven for thinking he's more likely to try to convert some of his stake into cash sooner than his peers given his earlier behavior.
Potential IPO-related income: If Facebook 's value is $100 million, he'll make $2.5 billion with his existing shares--asuming he still maintains that 2.5% stake.
What he's doing about the money: Protecting it! In order to save himself a massive capital gains-related tax bill in the U.S., Saverin has renounced his U.S. citizenship. He was originally born in Brazil, moving to Miami when young, and has been living in Singapore for several years now. The payoff may be in the tens of millions of dollars, but it's possible that Saverin may be barred from entering the U.S. in the future due to laws relating to renouncement of citizenship to avoid tax.
What else he's doing: Not living  a Playboy lifestyle, apparently...although he does drive a Bentley and frequent "exclusive" clubs. He's reported as believing Singapore to be the best place to invest in IT companies for the future, and is said to plan investments into Brazilian companies that are targeting the Asian markets. He's also just helped fund  mobile wallet effort CrowdMob, a firm mixing up app-promotion with local coupons with an eye on the future mobile payments market.
Read about others in the Facebook IPO Players Club :
- Chris Hughes 
- Sean Parker 
- Peter Thiel 
- Dustin Moskovitz 
- Reid Hoffman 
- David Choe 
- Donald Graham 
- Jim Breyer 
- Li Ka-shing 
- Jeff Rothschild 
- Sheryl Sandberg