Facebook Inc. (FB)’s co-founder and chief executive officer, Mark Zuckerberg, continued his fall down the ranks of the world’s billionaires as the company’s shares plummeted to a record low.

The 28-year-old’s fortune plunged to $12 billion from $13.7 billion yesterday, according to theBloomberg Billionaires Index. Shares of the world’s largest social-networking company sank as much as 17 percent after the company reported its second-quarter operating margin dropped from a year earlier and sales grew at the slowest pace on record. The shares were down 13.7 percent to $23.62 at 11:50 a.m. in New York.

“They are probably a little bummed out right now,” Herman Leung, an analyst at Susquehanna Financial Group, said in a telephone interview from his San Francisco office. “Facebook has to balance more of a fine line between delivering numbers for Wall Street and deciding how much monetization it’s going to push toward impacting its user base.”

Source: Bloomberg