Lack of profits and the threat posed by western countries are raising concern about the sustainability of Beijing’s AI boom

Trillions of dollars have been wiped from China’s stock markets in recent months amid increasing anxiety about the future of artificial intelligence, as Beijing races against the United States for dominance in the sector.

The STAR 50 Index, which tracks technology and innovation companies on the Shanghai stock exchange, has plunged 40% since June. Other indexes of major companies dropped by about 20% over the same time period.