American depositary shares of the company opened at $10.25, before recovering to $11.50. The shares were priced at $12 apiece in the IPO, raising $360 million through the stock sale.

Waterdrop's founder and chief executive, in an interview with Reuters earlier in the day, said the company would focus more on user growth than on profit in the short term.

The company aims to be China's version of UnitedHealth Group in a decade and has no plan to revive its once popular mutual aid service, Shen Peng said.

The loss-making company will focus until 2025 on growing its online insurance business in China, and would like to expand further into healthcare businesses in 10 years' time in the country, Shen said. UnitedHealth is the biggest U.S. health insurer.

"Currently becoming profitable is not our priority," said Shen, adding that growth and serving more users was more important in the short term.

Waterdrop's stock market debut was seen as a key test of investor appetite for Chinese fintech companies amid a regulatory crackdown that started after the halting of Ant Group's IPO last November.

Waterdrop doesn't plan to restore its mutual aid service, which was shut down in March and had provided 80 million users with shared basic health plan covering critical illnesses, as Shen believes such services are out of fashion and cost-effective insurance policies underwritten by insurance carriers will prevail in China's lower-tier cities.

China's financial regulators have said since late last year that all financial activities needed to be overseen by regulators and all businesses needed to be licensed to operate.

Last month, Chinese financial regulators said that they would step up efforts to regulate fintech companies that have offshore public listing plans.

Shen said that the company started to proactively communicate with regulators when it first had the IPO idea and kept talking with regulators at every step of the IPO process.

"Regulators have expressed that they are delighted to see innovative companies obtain public listings as long as the companies' operations comply with regulations," Shen said.

Founded in 2016 by Shen, a former executive at Chinese food delivery giant Meituan, Waterdrop was valued at about $2 billion in a pre-IPO funding round last August. It also counts reinsurer Swiss Re, Boyu Capital, and Meituan as investors.

Beijing-based Waterdrop's remaining core businesses include distributing insurance policies online and providing illness crowd-funding.

The company said in its filing that its revenue hit 3 billion yuan ($464.43 million), an increase of over 100% year on year.

($1 = 6.4596 Chinese yuan renminbi)

(Reporting by Yingzhi Yang and Tony Munroe in Beijing; Additional reporting by Medha Singh in Bengaluru; Editing by Sumeet Chatterjee, Muralikumar Anantharaman and Sriraj Kalluvila)

By Yingzhi Yang and Tony Munroe