The European Central Bank on Thursday unveiled a much-anticipated program to buy government and private bonds starting in March. The program was bigger than investors expected.
The euro fell in response, down to $1.148 from $1.162 just before the news. The currency's lower value could make European goods cheaper, boost exports from the region and lift inflation from dangerously low levels.
The Standard & Poor's 500 index rose 10 points to 2,041 in early trading. The yield on the 10-year U.S. Treasury note dropped to 1.84 percent, from 1.94 percent just before the ECB announcement. When bond prices rise, yields fall.