The Standard & Poor's 500 index rose 13 points, or 0.7 per cent, to 2,036 as of 11:57 a.m. Eastern time Wednesday. The Dow Jones industrial average climbed 56 points, or 0.3 per cent, to 17,571. The Nasdaq gained 28 points, or 0.6 per cent, to 4,682.
Stocks of energy companies rose the most among the 10 sectors in the S&P 500, as the price of benchmark U.S. crude oil climbed 3 per cent to $47.92 a barrel.
European markets were mostly higher as investors awaited the European Central Bank's decision Thursday on another wave of economic stimulus.