Art Cashin says there's "mild bafflement" on the NYSE floor about why stocks are down on this first trading day of the year.
Cashin, UBS' director of floor operations at the NYSE, told CNBC's Bob Pisani around midday that "you have some disjointed things. Gold has popped. We were kind of looking forward to that given the tax selling... But they're also looking for prefunded IRAs and other things to take the stock averages higher and that hasn't occurred."
Cashin adds, "I've been hearing convoluted theories about it having something to do with the pop in the (U.S.) dollar but I can't get anyone to explain to me where that arbitrage lies."
He does think there could be something to the theory that U.S. stock are reacting to weak economic data from China. "It could be that China overrides everything."