China's stocks and currency came under pressure as markets returning from a week-long break were greeted by a new trade dispute with the United States and ructions in the global artificial intelligence sector.

China is preparing for a potential probe into how Apple deals with developers, including taking a 30% cut on in-app spending, according to a report.

Nio ( NIO -2.31%), one of China's largest premium electric vehicle (EV) players by sales, was always an intriguing investment opportunity. It gave investors a path into China's booming EV market, which was heavily subsidized by the government and is poised to take over roads globally.