Those shares are still worth about $68.5 billion.
Despite his losses, Zuckerberg is still the fourth richest person in the world, behind Jeff Bezos, Bill Gates and Warren Buffet, according to Bloomberg.
With Monday’s plunge, Facebook shares are down about 2.6 percent year-to-date. The stock pared losses slightly during Monday trading.
Cambridge Analytica made headlines as the political data analytics firm that worked on Facebook ads for President Donald Trump during the 2016 presidential election. Facebook blocked the firm’s data harvesting app in 2015, and announced on Friday it suspended the firm for lying about deleting user data.
Despite Facebook’s insistence it has done what it can to protect users’ data, the scuffle has stirred up discussion over tech regulations. Virginia Democratic Senator Mark Warner, one of the most prominent voices in the debate about online political advertising, said the Cambridge Analytica-Facebook spat indicative of a market that’s “essentially the Wild West” of advertising.