Stocks are edging lower in midday trading, pulling the market back from its latest record high.
Rite Aid fell 3 percent after reporting a 55 percent plunge in its latest quarterly earnings. Higher drug costs lowered the company's profits.
Kroger was among the big risers after the supermarket operator raised its earnings forecast for the year.
The Standard & Poor's 500 index fell one point, less than 0.1 percent, to 1,955 as of noon Eastern Time Thursday. It closed at a record high the day before.
The Dow Jones industrial average fell 29 points, or 0.2 percent, to 16,876. The Nasdaq composite lost nine points, or 0.2 percent, to 4,352.
Bond prices were little changed. The yield on the 10-year Treasury note held steady at 2.59 percent.