The S&P 500 was up 11 points, or 0.6 per cent, to 2,043 as of 12:08 p.m. Eastern time Thursday. The stock-market benchmark is headed for its fourth straight day of gains, its longest win streak this year, and is down less than 1 per cent for 2015.
The Dow Jones industrial average rose 99 points, also 0.6 per cent, to 17,653. The Nasdaq gained 36 points, 0.8 per cent, to 4,704.
Demand for U.S. government bonds rose and yields fell. The yield on the 10-year Treasury was 1.88 per cent, compared with 1.94 per cent just before the European plan was announced.