Copper prices declined 5.7 percent to $2.4945 per pound in New York and was a factor that drove U.S. stocks to decline, according to Bloomberg.
Investors showed some concern over data that showed a decline in retail sales during December, Bloomberg reports.
The Dow Jones Industrial Average tumbled 1.06 percent — or 186.59 to 17, 427.09, the S&P 500 composite index declined 11.76 points to 2, 011.27 and the NASDAQ composite index slid 22.17 points to 4, 639.32.
Top Percentage Gainers
 Company |  Stock Price |  $ Change |  % Change |
 Orbital |  26.68 |  1.13 |  4.42% |
 Serco Inc. |  2.35 |  0.07 |  3.07% |
 ATK |  119.94 |  2.08 |  1.76% |
 Navistar |  31.73 |  0.38 |  1.21% |
 Maximus |  55.84 |  0.30 |  0.54% |
Market Summary
Advancing Issues | Â 13Â (43.33%) |
Declining Issues | Â 17 (56.66%) |
Unchanged Issues | Â Â 0 |
The Executive Mosaic GovCon Index is a composite index that tracks 30 of the largest publicly-traded Government Contracting (GovCon) firms.