REUTERS – The Standard & Poor’s 500 edged lower on Monday as a four-week rally stalled, while a rebound in Apple shares helped buoy the Nasdaq. Caterpillar (CAT.N) shares helped cap losses in the Dow industrials after the heavy equipment maker’s outlook eased investors’ fears about an economic slowdown in China. Caterpillar’s shares rose 2.1 percent to $97.61. The...