Copper bounced off a five-month low to end stronger on Thursday as the dollar dipped and US equities rose, but it may face challenges going higher amid forecasts of only moderate Chinese and US growth. Benchmark July copper futures on the COMEX division of the New York Mercantile Exchange finished about 1.50 percent higher at $3.9705 cents a lb, then continued up to a 2 percent gain in after-hours business.