As the Dow Jones Industrial Average plunged over 800 points over concerns related to rising interest rates, U.S. companies from every industry took a dip, from banking giants such as Goldman Sachs (which fell 3.6%) to tech titans such as Apple (down 4.6%).

The world third-wealthiest person, meanwhile, shed roughly $4.5 billion on paper over the course of 24 hours, with his stake in Berkshire Hathaway now worth about $86.4 billion.

Berkshire shares (BRK-A) dipped 4.9% Wednesday—the stock’s worst one-day drop since Black Monday in August 2011. That selloff, which shook global markets, sliced over 600 points off the Dow Industrial Average, amid concerns about America’s ability to pay back its debts.

Berkshire is tied heavily to the fortunes of the U.S. economy. In addition to the companies it owns and operates, which are heavily concentrated in U.S. insurance and utilities, the majority of the investment stakes it holds are in big American companies—including blue chip firms such as Apple and Goldman Sachs.

So as the S&P 500 dipped 3.3%, the market value of Berkshire fell by $28.1 billion, to a market cap of roughly $528.9 billion.

Buffett is hardly the only billionaire with likely paper losses Wednesday. Jeff Bezos, the world’s richest man, saw his stake in Amazon lose about $9 billion in value, as that stock shed 6%.

Still, its hard to imagine the Oracle of Omaha in any mode of panic. The famed octogenarian has built his investing legend around one saying in particular: “Be fearful when others are greedy, and greedy when others are fearful.”