Facebook appears to finally be paying for the impact of fake news in the 2016 elections and user privacy concerns, with the stunning disclosure of a revenue deceleration in the second half of this year sending shares on a mind-blowing plunge Wednesday afternoon, writes Therese Poletti for MarketWatch.

During a conference call Wednesday, Facebook chief financial officer David Wehner predicted bad news for the second half, and the company’s shares immediately began a drastic retreat in the extended session. Should the after-hours bloodbath continue into Thursday’s trading session, Facebook would see a $100bn blow to its market cap, after shares plunged 20%.