Stocks finished sharply in the red Thursday, with the Dow down triple digits, weighed down by disappointing earnings from a handful of retailers and weak economic reports.
Meanwhile, the 10-year yield broke below the psychologically important 2.50 percent mark for the first time since last October.
"Volume is at its lightest of the year," noted Art Cashin, director of floor operations at UBS Financial Services. "We like to say 'volume is validity,' but that's not always true. A ship can sink in a quiet sea. That probably is a bit more ominous if we continue to go down as we have in light volume because it becomes evident that it's not heavy selling."