The hottest company in China right now is Cambricon Technologies, an artificial intelligence chipmaker whose stock has surged about 10-fold over the past two years, driven by expectations that it could be a serious challenger to Nvidia in the mainland market. The frenzy over Cambricon, whose stock is trading at an eye-watering trailing 12-month price-to-earnings ratio above 4,000 – compared to under 60 for Nvidia – reflects a growing belief in China that the country is on a path to develop an AI...