This ‘AI tiger’ just made its market debut. The stock soared 109%.

The stock soared 109% to 345 Hong Kong dollars on its first day of trading, following an initial public offering in which MiniMax raised HK$4.8 billion ($619 million) at an offer price of HK$165. The benchmark Hang Seng Index closed 0.3% higher.

MiniMax, which develops large-language models, is the second of China’s so-called AI tigers to go public this week. It did a lot better than rival Zhipu AI, which fizzled in early trading on Thursday before closing up 13% at HK$131.50 in Hong Kong.

MiniMax was founded in early 2022 and says on its website that its models and products have served more than 212 million individual users, across more than 200 countries and regions. Online retailer Alibaba and Abu Dhabi’s sovereign-wealth fund are among the company’s investors.

The stellar debut is the latest sign that China’s AI rally has legs, as Beijing bids to support local alternatives to U.S. companies such as Nvidia and OpenAI.

Chip designers Moore Threads Technology and MetaX Integrated Circuits racked up triple-digit gains when they made their stock-market debuts last month—and rival Shanghai Biren Technology soared 76% on its first day of trading last Friday.

Write to George Glover at george.glover@dowjones.com