US stocks Thursday plummeted about two percent in a broad sell-off attributed to a range of factors, including weak eurozone data, the Argentine debt default and disappointing US corporate earnings.
The Dow Jones Industrial Average tumbled 317.06 points (1.88 percent) to 16,563.30, erasing all its gains thus since the end of 2013.
The broad-based S&P 500 sank 39.40 (2.00 percent) to 1,930.67, a seven-week low, while the tech-rich Nasdaq Composite Index fell 93.13 (2.09 percent) to 4,369.77.
The rout followed a dreary day on European bourses, where the German DAX sank nearly two percent and indices in Britain and France fell sharply after eurozone data revived concerns about deflation and Adidas issued an earnings warning linked to the crisis in Ukraine.
Other big drags on the market included the Argentine debt default and disappointing earnings from Whole Foods Market, Kraft and others.
Some analysts also pointed to lingering concerns about high stock valuations after a string of records this summer by the Dow and S&P 500.
Michael James of Wedbush Securities said a "terrible" report by the Institute of Supply Management on midwestern manufacturing revived concerns about the US economic recovery.
"There isn't one thing you can point to," James said . "It's an accumulation of concerns that have kind of broken the dam today."