It was a gloomy start to the new year on Wall Street as stocks sank as part of a global sell-off.
Investors worried about new signs of a slowdown in China and a flare-up in tensions between Saudi Arabia and Iran. That sent the price of oil on another wild ride.
The Dow Jones industrial average made a last-hour comeback to avoid a historic opening-day decline, but still ended with its worst loss in two weeks.
The Dow slumped 276 points, or 1.6 percent, to 17,148. It was down 468 points earlier in the day, putting it on pace for its worse percentage loss since 1932.
The Standard & Poor's 500 index lost 31 points, or 1.5 percent, to 2,012. The Nasdaq composite fell 104 points, or 2.1 percent, to 4,903.
China's main index plunged nearly 7 percent, triggering a trading halt, after manufacturing slumped again.