Yum posted strong margin expansion in its second-quarter report.Shares of Yum China (YUMC 11.83%) were moving higher today after the company reported better-than-expected results in its second-quarter earnings report, overcoming consumer weakness in China.As of 11:07 a.m. ET, the stock was up 13.2%. Yum China overcomes a low barThe Chinese operator of KFC and Pizza Hut said that same-store sales were down 4% in the quarter, but overall revenue increased 1% to $2.68 billion, driven by new store openings and ...