Stocks tumbled again in the final hour of trading to close near session lows in heavily volatile trading Wednesday, with the Dow posting its sixth-straight day in the red, as investors digested the minutes from the latest Fed policy meeting.

Stocks initially spiked lower following the minutes but rebounded within a half hour to wipe out all of the day's losses. Selling renewed aggressively into the close, with the major averages closing near session lows.