It was among the biggest one-day losses of market value in USA stock market history.
Even so, Faceboook's crash dwarves that of the previous record holder, Intel, who lost $91 billion (£69 million).
Facebook CFO David Wehner told investors revenue growth would decline significantly over the next few quarters, and that Facebook's operating margin would drop from 44% in Q2 to the mid-30% range over a time frame of more than the next two years. Also, while DAUs were up (against Q1 2018) in areas Facebook labels as "Asia-Pacific" and "Rest of World" it lost 3 million DAU in Europe (282 million vs 279 million) and stayed flat in the United States and Canada, at 185 million.
Fake news remains an ongoing struggle for the social media giant.
Facebook shares have already been through a rollercoaster of ups and downs this year, with the biggest slump coming in April after it emerged data from tens of millions of users had been acquired by Cambridge Analytica.
"With or without privacy issues, investors are scared that Facebook´s interactions, particularly with those under 25, are falling", Sheehan said. "Looking ahead, we will continue to invest heavily in security and privacy".
Facebook stock hammered after earnings miss, slow growth forecast
Strong ad sales from Google, which is Facebook's main competitor for online advertising, had sent expectations for the social network's earnings up, along with its stock price. The question is: When will they see a price point they like? Technology companies account for six of the 10 biggest companies in the S&P 500 Index. Facebook is rolling out a version of those protections to the rest of the world.
Facebook's daily active users in Europe declined by 3 million amid the new regulation.
Declining user growth, growing privacy awareness, and dwindling advertising profitability all seem to indicate trouble for the company in the future.
While analysts were stunned by Facebook's growth guidance and subsequent stock plunge, Business Insider's Jim Edwards pointed out that Zuckerberg warned three months ago that bad news was coming, and no one listened.
Facebook had the largest-ever loss of value in one day for a U.S. traded company. Stamos reportedly still plans to leave the company next month, following a reorganization that the New York Times said earlier this year took away 98% of the group he managed. But most experts believed the company had successfully dealt with them.
This drop wipes out $100 billion from the company's market cap, according to Birinyi Associates.
Facebook CEO Mark Zuckerberg speaks during the F8 Facebook Developers conference on May 1, 2018, in San Jose, Calif.More news: 32 killed as Pakistan votes to elect new government
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