Stocks opened higher on Friday, putting the S&P 500 on track for a fourth straight gain in the wake of an aggressive plan by the Federal Reserve to stimulate the economy.

The Dow Jones industrial average <.DJI> was up 29.66 points, or 0.22 percent, at 13,569.52. The Standard & Poor's 500 Index <.SPX> was up 3.74 points, or 0.26 percent, at 1,463.73. The Nasdaq Composite Index <.IXIC> was up 11.24 points, or 0.36 percent, at 3,167.07.

(Reporting by Ryan Vlastelica; Editing by Dave Zimmerman)