China's stock market loses $2.4 trillion as AI boom doubts weigh on valuations

Chinese mainland stocks have lost about $2.4 trillion in market value since May, with the STAR 50 index of tech and chip companies down 40% in under four months. AI companies account for 42% of the market value and 57% of trading volume on Chinese shares, and their declines are dragging down the broader CSI 300 index, which entered a bear market in late October. The sell-off is attributed to weak consumer spending and doubts about whether AI firms can earn back their investments, while U.S. export controls on chips and robot parts add further pressure.