Internet, Billionaire | featured news

Facebook's stock market debut left founder and CEO Mark Zuckerberg with a paper fortune currently valued at $13 billion -- and a 2012 tax bill of around $1.1 billion.vZuckerberg's whopping tax hit stems from his move last May to increase his stake in Facebook. On the day of Facebook's initial public offering, Zuckerberg exercised a stock option and purchased 60 million Facebook shares at a "strike price" of 6 cents each.

Michael Rubin is lucky. And he’s also damned good. Lucky, because eBay approached him last year with a $2.4 billion offer to buy his moneylosing GSI Commerce–which provides Web design, customer service and shipping to big-brand retailers–a 51% premium over the share price. Damned, because Rubin has always played so loose and fast that he’s nearly brought on his own ruin–and stoked the wrath of shareholders. Good, because he has an uncanny eye for undervalued assets and a lifelong talent for turning them into gold.

Another 17 of America's richest people, including Facebook's Mark Zuckerberg, junk bond pioneer Michael Milken and AOL co-founder Steve Case, have pledged to give away most of their wealth.

Investors rallied to push shares of newly public Chinese video site Youku up 160% from the offering price –and minted a new billionaire in the process. Youku founder and Chief Executive Victor Koo owns 34.8% of the company, according to a prospectus filed with the SEC. That means his share of the company –which TechCrunch pointed out now has a $3.3 billion market cap (greater than that of AOL) – is worth $1.1 billion. Koo joins the growing herd of Chinese tech billionaires, the best known of which is Baidu’s Robin Li the second richest man in China, according to Forbes.