Shares of artificial intelligence chipmaker Shanghai Biren Technology tumbled more than 12 per cent in Hong Kong on Thursday amid plans to raise HK$4 billion (US$510 million) through a share placement, as competition with other Chinese Nvidia challengers intensifies. The sell-off followed a stock exchange filing by the Hong Kong-listed company on late Wednesday, which revealed it had engaged placing agents on a “best effort” basis to issue 130 million new shares at HK$31.08 apiece. The offering...