Stocks sank again after another wild day, extending a rout that left Wall Street with its worst week since October 2008.
The stock swoon is being driven by fear that the coronavirus outbreak will derail the global economy.
The Dow Jones Industrial Average lost 357 points, or 1.4%, to 25,409. The S&P 500 lost 24 points, or 0.8%, to 2,954. The benchmark index has lost 13% since hitting a record high 10 days ago. The Nasdaq rose 1 point to 8,567.
The virus outbreak has been shutting down industrial centres, emptying shops and severely crimping travel all over the world.
More companies are warning investors that their finances will take a hit because of disruptions to supply chains and sales. Governments are taking increasingly drastic measures as they scramble to contain the virus.
The market's losses moderated somewhat after the Federal Reserve released a statement saying it stood ready to help the economy if needed. Investors increasingly expect the Fed to cut rates at its next policy meeting in mid-March.
Stocks in Europe also fell including the FTSE 100, the CAC 40 and the DAX.