The People's Bank of China devalued the CNY against the USD today:
That is the weakest for the CNY at its reference rate setting since August of 2017 and the biggest jump since January of 2017
You can think about a currency devaluation like this as sorta like (not quite, but bear with me) a tariff - by dropping the value of the currency (remember, the PBOC control the yuan price, it is not a floating currency) it makes the price of goods (in USD in this example) more expensive.
Make no mistake, this is a retaliation move from China to yesterday's announcement from the US of more tariffs - the trade war is escalating.
