US stocks opened flat on Tuesday as investors exercised caution ahead of possible policy action from the Federal Reserve and a key decision by a German court.

The Dow Jones industrial average was up 25.71 points, or 0.19 percent, at 13,280.00. The Standard & Poor's 500 Index was up 1.68 points, or 0.12 percent, at 1,430.76. The Nasdaq Composite Index was up 1.77 points, or 0.06 percent, at 3,105.79. - Reuters