SP 500
The 50 day moving average is around 1081 and the 50 percent retracement for the entire decline is indicated on the chart.
Today's rally appears to be a technical relief rally, in which the market professionals and insiders use positional knowledge to squeeze the speculators who were holding to the short side. 
NDX
“I know there is a God — I see the storm coming and I see His hand in it — If He has a place for me then I am ready.”
John F. Kennedy, scrawled on a prayer breakfast program, NYT, May 15, 1964