In the week since Facebook Inc. (Nasdaq: FB) went public, its founder, CEO and majority shareholder saw his $20.2 billion stake in the social media giant quickly swell to $24 billion only to shrink by day's end to $17.6 billion.

In other words, in less than the approximately five days Mark Zuckerberg's 533 million shares were publicly traded the 27-year-old college dropout lost $6.4 billion.

Many had expected the IPO to provide Zuckerberg with a boon. But his value is virtually identical to Forbes' valuation of the young CEO, leaving his spot unchanged on the magazine's Billionaires list. Had he sold his shares at the company's initial peak (or had Facebook maintained around $45 a share), he would have leap-frogged 20 places to No. 15, ahead of L'Oreal's Lilian Bettencourt -- passing Google founders Sergey Brin and Larry Page along the way.

Other Facebook Brass Take A Wealth 'Hit' As Well

Facebook's stock fluctuations also hurt some of Zuckerberg's high-profile deputies. For example, Chief Operating Officer Sheryl Sandberg's nominal stake in the company has fallen $22.7 million, with her 1.9 million shares topping out $85.4 million on Friday before hitting $62.7 million at Wednesday's close.

One of the company's biggest initial investors, and Facebook's biggest minority owner, Jim Breyer, saw his 201 million shares go from $9 billion to $6.4 billion in value.

All of this neglects the disappointment in dashed expectations. Facebook and prognosticators were hoping for a $100 billion valuation -- a long climb from its actual market cap of $68.4 billion.

Still, Zuckerberg's $17 billion is nothing to scoff at, when you consider he started Facebook in his Harvard dorm room eight years ago.