The S&P 500 sank 4.8%, more than in major markets across Asia and Europe, for its worst day since the pandemic crashed the economy in 2020. The Dow Jones Industrial Average dropped 1,679 points, or 4%, and the Nasdaq composite tumbled 6%.

Stocks of the biggest banks and private-equity firms plunged Thursday as concerns mounted about how Wall Street giants and their customers might be affected by heightened odds of a US recession.