Stocks tumbled on Friday, with the S&P 500 index down 3 percent after a top German official at the European Central Bank resigned in protest of the bank's bond-buying program, which has been a major tool in fighting the region's debt crisis.

The Dow Jones industrial average <.DJI> lost 339.44 points, or 3.01 percent, to 10,956.37. The Standard & Poor's 500 Index <.SPX> fell 35.32 points, or 2.98 percent, to 1,150.58. The Nasdaq Composite Index <.IXIC> dropped 71.97 points, or 2.85 percent, to 2,457.17.