Last week, China's market regulator fined some of the market's biggest players, including Alibaba-backed start-up Nice Tuan, Tencent-backed start-up Shixianghui, Pinduoduo's Duoduo Maicai, Meituan Youxuan and Didi's Chengxin Youxuan, for slashing prices to edge out competitors and breaching the country's price law.