Facebook has shed almost $50 billion in value since its debut -- more than the total valuation of Hewlett-Packard Co or Starbucks Corp. The stock debuted at $38.
A Dreamliner in Air India colours at an airport in Washington
Facebook shares crumbled again on Thursday, sending the once-feverishly sought-after name below $20 for the first time as investors scrambled to get out of the way of a potential share deluge in coming weeks.