Facebook CEO Mark Zuckerberg lost approximately $17 billion after Facebook shares dropped by more than 19 percent at the opening bell on Thursday.

“His fortune tumbled by $16.8 billion in late trading Wednesday, as shares of the social media giant slid 20 percent at 5:37 p.m. in New York on disappointing results,” reported Bloomberg. “If that holds through Thursday’s close, he will slide to sixth place from third on the Bloomberg Billionaires Index. It would also wipe his $13.7 billion of gains for the year, leaving him with just less than $70 billion.”

Zuckerberg’s $17 billion loss is likely the largest one-day loss any single investor has ever suffered in the stock market, since few other investors have ever had as much to lose. Facebook’s overall market loss of at least $150 billion has been described by Bloomberg as a “rout that could rewrite the history books.”

Here's how Facebook's $151 billion rout could rewrite the history books https://t.co/3HkO51t9uB pic.twitter.com/aybM7HdB29 — Bloomberg (@business) July 26, 2018

On Wednesday, Breitbart News’ Joshua Caplan reported that “Facebook’s stock declined sharply as slowing global daily active users slow and scrutiny of data privacy issues continue to plague the social networking giant.”

“Facebook’s daily active users missed projections in North America, Europe, and on a global basis,” he explained.