(CNBC) The Dow Jones industrial average rebounded more than 300 points Friday, with buying in the final hour lifting the major indexes.

The index swung more than 850 points in volatile trading Friday. The S&P 500 and the Nasdaq composite joined the Dow in its trip higher, both rising more than 1.4 percent.

its lows Friday, the Dow had fallen more than 500 points or 2.1 percent. The average experienced two drops of more than 1,000 points and two gains of more than 400 points.

The S&P 500, meanwhile, broke below its 200-day moving average, a key technical level according to traders.

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