Where is it safe to be long? The chart above shows how we may be able to find support in the 2415-2400 level. If we there, an would be formed which should take us back for a test of the head-and-shoulders neckline break on the S&P (not pictured here) around 2620. This, however, will likely take many days to play out. I would expect to see another leg down from there.
Buy the S&P 500 on a pullback between 2400 and 2415. Use a stop of 2380, with a primary target of 2500 and a secondary target of 2625.