In this Friday, Dec. 28, 2012, photo, traders work on the floor at the New York Stock Exchange in New York. World stock markets headed lower Tuesday Jan. 8, 2013 as investors turned cau

 

              In this Friday, Dec. 28, 2012, photo, traders work on the floor at the New York Stock Exchange in New York. World stock markets headed lower Tuesday Jan. 8, 2013 as investors turned cau
In this Friday, Dec. 28, 2012, photo, traders work on the floor at the New York Stock Exchange in New York. World stock markets headed lower Tuesday Jan. 8, 2013 as investors turned cautious before U.S. earnings season kicks off this week. (AP Photo/Seth Wenig)