The iShares A50 ETF was the most highly traded securities on the Hong Kong exchange in January, the Financial Times reports.

The surge in activity is the latest sign of international appetite for exposure to China and the growing interest in Asia for index-based investments, according to the report.

The big rally in Chinese stocks since the beginning of September is one factor driving interest in the ETFs.

For example, the U.S.-listed iShares FTSE China 25 (NYSEArca: FXI) has gained 22% the past six months. Since the end of November, the ETF has gathered inflows of $1.8 billion, according to IndexUniverse data.

Last year, investors added $25 billion to China-related ETFs while Asian ETF assets rose 50%, according to the FT story.

“We believe that China has the largest growth potential in the ETF space given its opportunities for new providers and products,” Deutsche Bank analysts said in the report.

iShares FTSE China 25