Wall Street closes lower as investors ready for earnings

Wall Street closed slightly lower on Monday, with gains in materials and banks countered by declines in consumer staples shares, as investors girded for the start of an earnings season expected to be gloomy. Investors are next looking for cues from the first-quarter earnings season, beginning in earnest with Alcoa's report after the bell on Monday. Ahead of the results, Alcoa shares rose 3.9 percent.