Chipmaker CXMT surged more than fivefold on its Shanghai trading debut to become the largest mainland-listed company by market value as the artificial intelligence boom stokes demand for memory chips. The stock closed at 49 yuan, versus a sale price of 8.66 yuan. That gave the Hefei-based company a market capitalisation of 3.3 trillion yuan, surpassing Industrial and Commercial Bank of China. It traded as high as 55.03 yuan during the day on the tech-heavy Star Market. CXMT raised 57.92 billion...