U.S. stocks open lower after PBOC's move to lower reserve requirement ratio

U.S. stocks opened mildly lower on Monday after the People's Bank of China (PBOC) announced to lower its reserve requirement ratio (RRR) for commercial banks by 0.5 percentage points.

The move, the first cut of its kind this year, aims to "ensure reasonably ample liquidity in the financial system; guide a stable and appropriate growth in credit; and create a favorable financial environment for supply-side structural reform," the Chinese central bank said Monday in a statement.

To boost economic growth, which in 2015 slowed to its lowest level in a quarter of a century, the central bank lowered the RRR five times last year.

Meanwhile, investors were still sifting through the U.S. economic growth data for the fourth quarter of 2015.

According to the second estimate released Friday by the Commerce Department, U.S. real gross domestic product (GDP) increased at an annual rate of 1.0 percent in the fourth quarter of 2015, beating the market consensus of 0.4 percent.

In the previous estimate, the increase in real GDP for the fourth quarter of 2015 was 0.7 percent.

Shortly after the opening bell, the Dow Jones Industrial Average fell by 20.34 points, or 0.12 percent, to 16,619.63. The S&P 500 dipped by 2.56 points, or 0.13 percent, to 1,945.49. The Nasdaq Composite Index was down 5.67 points, or 0.12 percent, to 4,584.81.

On Friday, U.S. stocks closed mixed after wavering in a tight range, as Wall Street digested the newly-released GDP report. Endi