Todd Spangler, writing for Variety:
Shares of Facebook plunged more than 19% in early trading Thursday, as investors reacted to signs that the social-media giant’s user and revenue growth are significantly slowing down.
The stock drop, to its lowest levels in nearly three months, wiped out more than $110 billion in market capitalization for Facebook and dragged down other internet and tech stocks including Twitter and Snap. Facebook’s market cap was $629.6 billion at the close of market Wednesday, and stood at around $503 billion as of Thursday at 10:30 a.m. ET.