The CSOP Hang Seng TECH Index ETF saw turnover of some HK$3 billion ($387.1 million) on its debut, surpassing the Tracker Fund's (2800.HK) previous record of HK$2.86 billion registered in 1999, its manager CSOP Asset Management Ltd said.

It also saw over $383 million in subscriptions, boosting the fund's size 16 times to $400 million on the first day of listing.

The ETF traded at a significant premium over its net asset value on the secondary market at the start of the morning session, prompting the fund manager to flag trading risks.

The CSOP ETF is the first fund of its kind to track the newly-published Hang Seng TECH Index, which is made up of the 30 biggest tech companies listed in Hong Kong, including Tencent Holdings and Alibaba Group.

The fund gives investors "an easy, transparent and efficient investment tool to replicate the performance of the fast-growing Chinese technology sector," CSOP Asset Management managing director Melody He said in a statement.

A looming technology decoupling between China and the United States amid trade and security tensions is accelerating home listings by Chinese tech companies, fuelling demand for tech-focused funds in Hong Kong and China.

Other asset managers including China Asset Management Co (ChinaAMC), Dacheng Fund Management Co and BlackRock are all preparing for ETFs tracking the Hang Seng TECH Index, dubbed the "Nasdaq of the east."

($1 = 7.7501 Hong Kong dollars)

(Reporting by Samuel Shen and Andrew Galbraith; Editing by Jan Harvey)