Existing home sales in the U.S. continued to improve in the month of August, according to a report released by the National Association of Realtors on Wednesday, with sales rising by much more than economists had anticipated. NAR said existing home sales jumped 7.8 percent to an annual rate of 4.82 million in August from 4.47 million in July. Economists had expected existing home sales to climb to an annual rate of 4.55 million.