Investors were already selling stocks lower on concerns about the holiday shopping season before the Institute for Supply Management, a trade group of purchasing executives, said its index of manufacturing activity fell to a 26-year low in November.
At the same time, the Commerce Department said construction spending fell by a larger-than-expected amount in October.
Both the housing and manufacturing sectors have been suffering for some time, so the reports were ultimately unsurprising. Wall Street is concerned that consumers, by curtailing their spending further, won't be able to help lift the economy from its slump.
The Dow is down about 331 points to the 8,497 level. Broader indexes are down more than 4 percent.