Chinese autonomous-driving start-up Momenta drew massive subscription numbers for its HK$5.89 billion (US$751 million) initial public offering in Hong Kong, even as it competed against five other issuers launching their IPOs at the same time. The Suzhou-based company’s bookbuilding closed on Friday. Preliminary figures showed that it attracted nearly 210,000 subscription applications, with the public offering subscribed 414 times, according to people familiar with the matter.