U.S. stocks extend rally on ECB announcement

U.S. stocks added gains at midday Thursday, boosted by the bigger-than-expected eurozone quantitative easing (QE) program announced by the European Central Bank (ECB).

At noon, the Dow Jones Industrial Average climbed 103.00 points, or 0.59 percent, to 17,657.28. The S&P 500 advanced 12.42 points, or 0.61 percent, to 2,044.54. The Nasdaq Composite Index jumped 39. 65 points, or 0.85 percent, to 4,707.07.

The ECB announced 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 size of the eurozone QE program beat 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 Thursday.

U.S. house prices rose 0.8 percent in November on a seasonally adjusted basis from the previous month's revised reading of 0.4 percent, beating market consensus, according to the Federal Housing Finance Agency.

In corporate news, eBay shares surged 4.87 percent to 55.98 dollars apiece around midday Thursday, as the global commerce platform and payments leader reported its adjusted earnings increased to 0.90 dollar per diluted share in the fourth quarter of 2014 from 0.81 dollar per share a year ago after Wednesday's closing bell. Endite