U.S. stocks open lower after three-day rally

U.S. stocks opened lower Friday as investors were looking for excuses to lock in gains after a three-day rebound.

U.S. stocks kept rising Thursday, with all three major indices logging a three-day winning streak, as Wall Street continued to cheer over the Federal Reserve's decision to leave its interest rates unchanged.

The Nasdaq Composite Index extended record run Thursday, refreshing its intraday and closing records for the second time in the past three sessions.

Meanwhile, investors were still sifting through the Fed's policy meeting ended early this week.

"The Committee judges that the case for an increase in the federal funds rate has strengthened but decided, for the time being, to wait for further evidence of continued progress toward its objectives," the Fed said in a statement after the conclusion of its two-day policy meeting.

"The economy has a little more room to run than might have been previously thought. That's good news ... we don't see the economy as overheating now," Fed Chair Janet Yellen said at a press conference following the release of the statement, suggesting the Fed had the opportunity to allow the labor market to continue to improve without running a hot economy.

Shortly after the opening bell, the Dow Jones Industrial Average fell 32.53 points, or 0.18 percent, to 18,359.93. The S&P 500 lost 5.32 points, or 0.24 percent, to 2,171.86. The Nasdaq Composite Index was down 12.59 points, or 0.24 percent, to 5,326.93. Endi