Mark Zuckerberg lost $29 billion in his net worth on Thursday with Facebook's "meta" company hitting a record low in one day.
Meta stock fell 26%, wiping out more than $200 billion in the largest-ever drop in the market value of an US company in a single day.
This reduced the net worth of founder and CEO Zuckerberg to $85 billion, according to Forbes magazine.
Zuckerberg owns about 12.8% of the shares of the technology giant, formerly known as "Facebook".
After wiping out $29 billion from his fortune, Zuckerberg ranked 12th on the Forbes list of billionaires, behind Indian business magnates Mukesh Ambani and Gautam Adani.
Meta shares fell about 25%, and 29% in one month, in after-hours trading after the company reported lower-than-expected revenue numbers, as well as a drop in Facebook users for the first time in its 18-year history.
Zuckerberg issued a reminder — and an obvious warning — for Facebook Messenger users who film their conversations.
He said in a post on Friday that the Messenger update will notify users if a photo of their conversation was taken by someone else.