U.S. stocks open lower after Fed chair's speech

U.S. stocks opened lower Tuesday as investors meditated on the comments from Federal Reserve Chair Janet Yellen.

The Fed was shifting its focus from stimulating the economy to keeping growth on an even keel, Yellen reportedly said Monday after the closing bell.

Yellen said during an event at the University of Michigan that the economy was "pretty healthy," thanks in part to the Fed's long-running stimulus campaign, which the central bank is moving to end.

The Fed raised its benchmark interest rate in March for the third time since the financial crisis, and said it planned two more rate increases this year.

According to the minutes from the Fed's March meeting, the central bank also planned to begin reducing its large holdings of securities by the end of the year.

On the economic front, February's job openings and labor turnover report will be released later in the morning.

Shortly after the opening bell, the Dow Jones Industrial Average fell 25.00 points, or 0.12 percent, to 20,633.02. The S&P 500 lost 4.85 points, or 0.21 percent, to 2,352.31. The Nasdaq Composite Index decreased 9.06 points, or 0.15 percent, to 5,871.86.

On Monday, U.S. stocks ended slightly higher as investors continued to digest the nonfarm payrolls report for March. Endi