U.S. stocks open higher on ECB announcement

U.S. stocks opened modestly higher Thursday, with benchmark indices extending their rally into a fourth straight session, after the European Central Bank (ECB) decided to launch euro zone quantitative easing (QE).

The ECB announced on Thursday to start QE by purchasing public and private securities in a bid to address prolonged low inflation.

ECB President Mario Draghi said at a press conference following the bank' s policy meeting that "the combined monthly purchases of public and private sector securities will amount to 60 billion euros. They are intended to be carried out until end-September 2016."

The announcement boosted investor euphoria, as the size of the euro zone QE program was bigger than market expectations of a 50-billion-euro monthly purchasing program.

On the economic front, in the week ending Jan. 17, the advance figure for seasonally adjusted initial claims was 307,000, a decrease of 10,000 from the previous week's revised level, said the U.S. Labor Department on Thursday.

Shortly after the opening bell, the Dow Jones Industrial Average rose 43.86 points, or 0.25 percent, to 17,598.14. The S&P 500 added 6.41 points, or 0.32 percent, to 2,038.53. The Nasdaq Composite Index was up 8.48 points, or 0.18 percent, to 4,675.90. Endi