Look out the window of any office building on Wall Street and you'll see bulls licking their wounds while struggling to find their footing. Stocks suffered their biggest one-day decline since July on Thursday, with all 10 primary S&P sectors lower on the day and most down more than 1 percent.

Not only has the dropped for four of the past five sessions, it closed below its 50-day moving average for the first time since Aug. 15.