Art Cashin: Why the bulls have 'an uphill fight'

Four sets of options expire during Friday's trading session—an event known as "quadruple witching"—and that has veteran trader Art Cashin warning of a negative bias for all of next week.

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"The bulls have a bit of an uphill fight to go here," Cashin told CNBC on Thursday. "The volume itself is very light here. They're not dumping things. It's more of a buyers' boycott—I guess an exhaustion pullback so far."

Thursday's trading session saw across-the-board declines across major averages, a day after the markets continued a four-day rally following the Federal Reserve's policy-setting meetings and another $10 billion reduction in its asset purchasing program.

Cashin told CNBC that Fed Chair Janet Yellen seemed determined not to get involved in the market's concerns over inflation or employment data. Traders remain concerned, however, over the potential for a wider Sunni uprising in Iraq, he added.

By CNBC's Jeff Morganteen