Stocks ended a second week of losses on a down note on Friday, reflecting growing worries that stocks are on the precipice of a pullback.

The Dow Jones industrial average <.DJI> was down 100.25 points, or 0.79 percent, at 12,595.67. The Standard & Poor's 500 Index <.SPX> was down 10.88 points, or 0.81 percent, at 1,337.77. The Nasdaq Composite Index <.IXIC> was down 34.57 points, or 1.21 percent, at 2,828.47.

For the week, the Dow fell 0.3 percent and the S&P lost 0.2 percent while the Nasdaq ended little changed, up 0.03 percent.