Mark Zuckerberg offloaded Facebook stock in the hours before the storm over polling firm Cambridge Analytica broke saving himself about $40 million (£28.5m).
The boss of Facebook sold 465,400 shares on Friday at an average price of $183.79, for a total transaction of $85,535,866.
Facebook’s share price plunged on Monday after weekend revelations emerged that details of about 50 million Facebook users was improperly forwarded to UK-based data consultants Cambridge Analytica.
There is no suggestion Zuckerberg has acted improperly in disposing of the stock. He has been selling stock at regular intervals over the last few months.
Facebook shares ended trading 6.7% lower at $172.56 on Monday, wiping almost $37bn off the social network’s market value.
According to website MarketWatch, the 4.9 million shares Zuckerberg has sold this year under a predetermined plan would be worth $855 million.
Zuckerberg made about $900 million selling those shares, according to calculations using average weighted prices reported to the Securities and Exchange Commission.
The billionaire announced last year that he intended to sell at least $6 billion in Facebook stock over the next 18 months to fund the Chan-Zuckerberg Initiative, a philanthropic venture established with his wife, Priscilla Chan.
In February, he sold nearly $500 million worth of shares. Zuckerberg owns 16% of the company and personally saw his fortune fall $5.5bn to $69bn on Monday.
Facebook has been accused of failing to make users aware that their profile information may have been harvested and sold to Cambridge Analytica.
Authorities on both sides of the Atlantic are now launching investigations into both companies.
In the UK, Information Commissioner Elizabeth Denham has confirmed she is seeking a warrant to search Cambridge Analytica’s London offices and examine what is held on its databases and servers.
MPs are also keen to speak to Zuckerberg as part of a wider inquiry.
In the US, moves are afoot by senators to call the Facebook supremo before a hearing into data security.
While Cambridge Analytica has denied any wrongdoing, its executives were caught on hidden cameras in a Channel 4 News expose on Monday night discussing how to smear political rivals and influence elections.
This is the firm that many believed helped Donald Trump win the US presidential election.
For Facebook, it suspended Cambridge Analytica on Friday – ahead of the revelations in the New York Times, UK-based Observer and Channel 4.
Various executives have taken to social media to defend its privacy record but Zuckerberg has said nothing.