Shares in CXMT, China's largest memory chip maker, soared more than 470% on their debut on Shanghai's STAR Market, briefly making it the most valuable listed company in mainland China. The surge is notable because it came despite a global sell-off in technology stocks this month, and offers reassurance to Chinese officials who have been trying to steady a stock market slump that had wiped out over $1.5 trillion in recent weeks.

The listing values CXMT at around 3.3 trillion yuan ($487.3bn; £364.9bn). Founded in 2016 by Chairman Zhu Yiming and based in Hefei, the firm makes Dram memory chips used in AI data centres, phones, PCs and tablets, and says it will use most of the IPO proceeds to expand production and research. The move comes weeks after South Korea's SK Hynix, a key Nvidia supplier, raised $26.5bn in a record US listing; Samsung, SK Hynix and Micron currently control around 90% of the global Dram market.