The prospect of a meeting between President Xi Jinping and US counterpart Donald Trump has become a focal point for investors seeking some reassurance on growth and stability as the conflict in the Middle East dampens appetite for risk. Investors are awaiting clarity on the summit, viewing it as a potential sign of cooperation that could steady mainland China and Hong Kong equities. The meeting had been scheduled for the end of the month, but the White House said it would be postponed by five or...