Mark Zuckerberg reportedly endured a world record $3 billion personal loss on Thursday, in the wake of executives’ suggestions that Facebook (FB) wouldn’t be able to maintain its rambunctious pace of growth going forward.
A chart posted by Bloomberg on Friday showed the Facebook co-founder and CEO’s net worth had dropped 6% the previous day. Facebook shares also fell by as much as 5.5% on Thursday morning, marking the largest slump in nine months, Bloomberg reports.
The stock’s downturn comes despite the social media giant posting a third-quarter sales increase of 56% on Wednesday.
“We had another good quarter,” Zuckerberg said in a statement. “We’re making progress putting video first across our apps and executing our 10 year technology roadmap.”
But CFO Dave Wehner’s use of the word “meaningful” to describe projected ad revenue growth slowdowns led analysts to speculate that the company’s pricey stock may finally have peaked.
Besides reduced ad revenue growth, Fortune‘s Erin Griffiths reports that there are concerns Facebook is running out of potential new users for its core “big blue” Facebook app, and that Google (GOOG) and others could chip away at its lead in the mobile advertising market.
For more on Facebook stock, watch Fortune’s video:
As of Thursday, Bloomberg’s Billionaires Index listed Zuckerberg as the world’s fifth richest person, with a $52.2 billion fortune.
