Halliburton rose 3 per cent after the oil exploration company posted a profit for the first quarter, bouncing back from a loss in the same period a year ago. Athenahealth, a provider of online services for the health care industry, slumped after its earnings fell short of analysts' forecasts.
The Standard & Poor's 500 index rose four points, or 0.2 per cent, to 1,868 in midday trading Monday. The index is coming off its best week since July.
The Dow Jones industrial average rose 25 points, or 0.2 per cent, to 16,434.
Bond prices rose. The yield on the 10-year Treasury note fell to 2.70 per cent.