'The Fed has to taper,' says Art Cashin

Art Cashin of UBS said Tuesday that a little-noticed announcement Monday lends further credence to the belief that the Federal Reserve will begin tapering in September.

"Last night the Treasury announced that their borrowing will be slashed by 25 to 30 percent for the balance of the year," he told CNBC. "So the Fed has to taper to not be disruptive. There's not enough supply out there, so they've got to cut back."