Hong Kong’s stock exchange had its busiest day of the year for new listings on Wednesday as five mainland Chinese companies made their trading debuts, cementing the city’s top global ranking for initial public offerings (IPOs). Semiconductor chip designer Fortior Technology was the biggest winner after its shares surged 16 per cent to HK$139.80. The Shanghai-listed company raised HK$2.26 billion (US$287.8 million) from its offering of new shares at HK$120.50 each. Apple supplier Lens Technology...