Mark Zuckerberg had a terrible, horrible, no good, very bad day.
The Facebook founder suffered a $3 billion loss in the value of his Facebook stock on Thursday, one of the largest single-day losses ever for an individual investor. Facebook (, Tech30) shares plunged 5.5% after the chief financial officer warned investorsthat the company expects revenue growth from advertising to “come down meaningfully.”
Zuckerberg holds 418 million shares of Facebook stock — still good for about $50.2 billion. Bloomberg estimates Zuckerberg’s total net worth at $52.2 billion, ranking him as the fifth-richest man in the world, just behind Warren Buffett. And despite Thursday’s plunge, Facebook shares are up nearly 15% for the year, lifting Zuckerberg’s net worth by $6.4 billion.