Facebook's value was down $111 billion (£85 billion) by the time Wall Street opened on Thursday
Mark Zuckerberg has lost around £13 billion of his personal fortune after Facebook suffered its worst ever day on the stock market. The figure accounts for around a sixth of his total net worth.
Facebook's stock value crashed as trading opened, with share prices falling by around 18% after a difficult second-quarter for the social media giants.
If the losses hold without any recovery in price, this will mean that Facebook will hold the record for the largest single-day drop of any company in stock market history in the United States.
The startling decline comes after Facebook reported user growth and sales that fell short of investor expectations, leading many shareholders to frantically sell their stock on Wednesday night before market close.
Other companies have, in the past, experienced similar plummets on the stock exchange, if not quite as severe as Facebook, who are currently battling new data laws and public concern over their privacy policies.
In 2013 Apple's shares dipped by $60 billion but have since bounced back to over three times the amount.
Even so, Faceboook's crash dwarves that of the previous record holder, Intel, who lost $91 billion (£69 million).
As it stands, Facebook still boasts 2.23 billion users, which make up almost a third of the entire population of Earth.
