From the AP: "The latest trouble started Aug. 11, when Beijing unexpectedly devalued China's currency, the yuan. Authorities explained that they wanted to catch up with investor sentiment, which suggested that the yuan was overvalued from having been linked to a rising U.S. dollar."
"In the aftermath, pain from slower Chinese growth and a weaker yuan could spread. Oxford Economics calculates that a 10 percent drop in the yuan this year would reduce South Korea's growth in 2016 by 1.16 percent and Indonesia's by 0.32 percent."