Bloomberg reports if that holds through Thursday's close, he will slide to sixth place from third on the Bloomberg Billionaires Index. It would also wipe his $13.7 billion of gains for the year, leaving him with just less than $70 billion.
Facebook Inc fell short of analysts' estimates for monthly active users on Wednesday and reported lower-than-expected quarterly revenue, months after the social network became embroiled in a data scandal affecting millions of users.
Nearly all of Facebook's revenue - US$13 billion of the total US$13.2 billion - came from online advertising, a sector dominated by the California social network along with Silicon Valley rival Google.
Facebook has been struggling for years with criticism about its content policies, its failure to safeguard private data and its changing rules for advertisers. In mid-March, The New York Times reported that Cambridge Analytica, a voter-profiling company, had effectively harvested the data of up to 87 million Facebook users.
During the conference call, Facebook executives warned that revenue growth rates will decline by "high single digit" percentages in the coming quarters.
In response, Facebook's stock tumbled more than 23 percent in after-hours trading, erasing more than $120 billion in market value in less than two hours.
The results missed Wall Street expectations.
At the same time, it could be an indication that the appeal of Facebook is slowly wearing thin, especially following all the privacy issues it has recently suffered. The company remains in a dominant position in mobile advertising alongside Alphabet Inc.'s Google. He crowed about Instagram, calling it an "amazing success" and said he believed that the unit grew twice as quickly under Facebook than it would have. Wehner said the drop was due entirely to a data protection and privacy law that took effect in Europe in May known as the General Data Protection Regulation, or GDPR.
Facebook said that it brought in adjusted earnings of about $1.74 per share for the period, which was two cents ahead of the Wall Street consensus estimate of $1.72 per share, according to Thomson Reuters.
Worldwide daily user growth for Facebook's namesake service slid for its sixth straight quarter, bringing it to almost 1.5 billion users in the second quarter.
Facebook has had a bruising few months, from ongoing fallout from the spread of Russian propaganda to the aftermath of the Cambridge Analytica scandal, and fierce controversy over whether fake news and disinformation should be allowed on the site.
Social networking giant Facebook (NASDAQ:FB) reported its Q2 2018 earnings today and we have to say that the tech giant has seen slightly better days. Given all the questions about the misuse of the platform, "to explain that there are a couple million people who chose not to continue using Facebook is unsurprising", said Brian Wieser, an analyst at Pivotal Research.
Unfortunately, the stock market frowned heavily on the slow growth rates, pushing Facebook's share price down over 7 percent in after-hours trading to around $200 per share. The company said headcount was 30,275 as of June 30 - an increase of 47 percent year over year.