American companies have started the trend of international financial firms tapping into Asia’s growing wealth. Hong Kong is a market that has attracted hedge funds and Wall Street titans such as Citigroup (NYSE: C).

The iShares MSCI Hong Kong (NYSEArca: EWH) is set to prosper with this new phase of development. The fund, which has a heavy weighing in the financial sector at 61% of the portfolio, is up about 8% over the past year. [China Readying Hong Kong ETF: Reports]

“These firms follow the flow of money, and there’s a lot of investable assets from individuals and institutions in the greater China region,” said John Mullally, who specializes in the private-equity and hedge fund industries for Robert Walters recruiting firm in Hong Kong, in a USA Today report.

Pension funds and sovereign wealth funds are setting up shop, with Soros Fund Management the most recent to set up an office in Hong Kong, according to the report. Hong Kong is viewed as the gateway to China for private equity firms. [Hong Kong ETF In Focus]

According to the latest Merrill Lynch Wealth Management data, the Asia-Pacific region now has the second-largest number of high-net worth residents, defined as those with $1 million or more in investable assets, minus their primary residence. It is second to North America.

Financial titans such as Citigroup are setting up Hong Kong offices to assist and serve families of the wealthy Asian investors. Employee count for the bank is scheduled to triple by 2013 to 12,000, USA Today reports.

According to CB Richard Ellis research, Hong Kong now takes third in popularity ranking for global banks and financial companies, coming in behind New York and London, tied for first.

Hong Kong and China stocks fell Wednesday as mainland insurers were under pressure, Reuters reported.