Trading under the stock code 2580, Aux opened at HK$16.10 amid a falling market, losing 7.6 per cent from its offer price HK$17.42, which was set at the top of the marketed range.
The company, based in Ningbo in eastern China’s Zhejiang province, raised HK$4.15 billion (US$531.79 million) from the sale of 238.24 million shares, including additional 31.01 million shares, or 15 per cent of the initial offering, after exercising an offer-size adjustment option.
The retail tranche was oversubscribed 557.2 times, triggering a clawback mechanism that lifted the public offering from 5 per cent to 35 per cent of the total shares. The international portion was 8.3 times oversubscribed, accounting for 65 per cent of the overall deal.

“Aux’s successful listing represents not only an important breakthrough and strategic positioning for the company in capital markets, but also marks a new starting point for promoting globalisation,” founder and chairman Zheng Jianjiang before striking the ceremonial gong to mark the start of trading. “Going forward, Aux will continue to increase research and development investment, promote digital transformation, give back to society with better products and services, and reward shareholders with superior performance.”
Hong Kong’s IPO market shows no signs of cooling, with a fresh batch of mainland Chinese companies receiving approval from the China Securities Regulatory Commission in the past week. The pipeline includes BYD supplier Hebei Haiwei Electronic New Material Technology, lidar-sensor maker Hesai Group, Chery Automobile, CF PharmTech and Chinese medicine maker Beijing Tong Ren Tang Healthcare Investment.