Chinese chipmaker CXMT soars more than 500% on debut

China's leading memory chipmaker CXMT became the most valuable company in the mainland after soaring 500 percent on its market debut Monday, underscoring the impact of AI-driven demand on the semiconductor sector. The firm's shares rocketed more than 500 percent by mid-morning, taking its market capitalisation to 3.5 trillion yuan ($520 billion) -- surpassing megabank ICBC as the mainland's most valuable company.