Average daily foreign exchange trading volumes rose 9% year-on-year in August, CLS said on Wednesday, as concerns about the health of the global economy sparked an increase in currency trading activity. CLS, a major settler of trades in the foreign exchange market, said in a statement that August's volumes increased to $1.75 trillion, higher than last year's $1.605 trillion. The August 2019 daily average was unchanged from July's number, however. Across the year, volumes rose across swap, spot and forward forex products, CLS said.