U.S. stocks extend gains amid Yellen's testimony

U.S. stocks ended mildly higher Tuesday after wavering in a tight range, as Wall Street digested Federal Reserve Chair Janet Yellen's comments delivered during her semi-annual testimony.

The Dow Jones Industrial Average rose 24.86 points, or 0.14 percent, to 17,829.73. The S&P 500 increased 5.65 points, or 0.27 percent, to 2,088.90. The Nasdaq Composite Index inched up 6.55 points, or 0.14 percent, to 4,843.76.

Yellen kicked off her two-day testimony before Congress with a session scheduled Tuesday morning before the Senate Banking Committee.

She reiterated the U.S. central bank's intention to raise interest rates, taking a cautious approach in view of an uncertain U.S. economy.

Yellen pointed out "considerable uncertainty" about the U.S. economic outlook, which includes slow job gains, weak investment, slow productivity growth, and vulnerabilities in the global economy.

"Proceeding cautiously in raising the federal funds rate will allow us to keep the monetary support to economic growth in place while we assess whether growth is returning to a moderate pace, whether the labor market will strengthen further, and whether inflation will continue to make progress toward our 2 percent objective," Yellen said.

Meanwhile, Britain's referendum was also in focus, which is set for Thursday. The latest polls showed the Remain camp making gains after the killing of British politician Jo Cox.

There is no major economic data due out Tuesday. Enditem