The United Kingdom voted to exit the European Union on Thursday, and news of the so-called Brexit rippled across worldwide stocks as markets opened on Friday.

Investor insecurity first struck at Japan’s Nikkei and Hong Kong’s Hang Seng, which shed nearly 8 percent and 3 percent respectively. The news then ravaged the European markets. The pan-European Stoxx 600 tanked 7 percent—its steepest daily decline since 2008—and London’s FTSE 100 dropped 3.15 percent. The British pound plunged by more than 11 percent, and European bank stocks plummeting by close to 20 percent. U.S. markets, which opened as chaos across the pond was in full swing, followed suit. Within minutes of opening, the Dow swung more than 500 points lower, closing out the day down nearly 3.4 percent.

Anxious investors bracing for an uncertain geopolitical crises and the possibility of a European recession sought refuge in the relative safety of gold and government bonds. Volatility went through the roof, while oil prices steeply dropped.

Of course, fears persist about how and when this concern on Wall Street will trickle down to Main Street. But the world’s richest individuals felt the effects immediately. The world’s billionaires lost a total of $99 billion on Friday, according to the Bloomberg Billionaires Index. The top 10 richest men shed a combined more than $21 billion alone. Bill Gates’s fortune declined $2.4 billion, while Amancio Ortega saw $6 billion float away. Warren Buffett said goodbye to $2.3 billion, and Jeff Bezos, who, until recently has been on a tear, lost $1.6 billion. For both Koch Brothers, it was just below $1 billion, and Carlos Slim, $2.7 billion. Mark Zuckerberg, who famously earned $6 billion in an afternoon earlier this year, gave nearly $1 billion back in the same amount of time on Friday. Larry Ellison and Ingvar Kamprad’s fortunes were $1.6 billion and $1.9 billion lower, respectively.