Staring at the computer screen in his office on the top floor of his electronic parts factory in Wenzhou, 47-year-old Chen Yanchuan, a native of this entrepreneurial town in Zhejiang province, is trying to figure out how much more money should he pour into his new-found passion: punting the Hong Kong stock market.

This is not a trivial decision and the money involved is hardly small change. So far, Chen said that he has "invested tens of millions of yuan in the Hong Kong stock market", with an expanding portfolio of "red chips", stocks of mainland enterprises listed on the Hong Kong bourse.

"I am not making a lot of money yet," Chen said. "But I will when I learn enough to dabble in derivative trading. The opportunities are limitless."

Chen is not alone among rich Wenzhou entrepreneurs in shifting their focus to Hong Kong at a time when the investment landscape on the Chinese mainland is clouded by a slowdown in economic growth and prolonged stock market doldrums.

Since the decline in overseas demand after the outbreak of the global financial crisis in 2008, many Wenzhou factory owners have been working hard to invest at least part of their fortune in acquiring assets to maximize their returns.

Chen, for instance, said he had invested in Shanghai properties, which he then sold when the government stepped in to dampen the price hike. He said he and a few "friends", also from Wenzhou, once bought several coal mines in Shanxi province to try to cash in on the escalating price of coal. They had no intention of running those mines, and sold them as soon as a good enough offer was presented.

It's not clear what triggered the rush for Hong Kong stocks. Of course, Hong Kong is no stranger to Wenzhou merchants. Many of them have already bought properties in Hong Kong, a free-market city where they can feel at home.

"Somehow word got round in Wenzhou that there is money to be made in the Hong Kong stock market," said Song Zhen, manager of Wenzhou Chaoyi Investment Co Ltd, one of the many brokerages that have set up special Hong Kong counters to service their expanding clientele.

More than 100 clients have opened accounts at Wenzhou Chaoyi to buy Hong Kong shares in the past year, said Song. Judging by the flood of inquiries, "we expect the number will double, or even triple, by the end of the year", he added.

Most of the investors trading Hong Kong shares through Song's brokerage are old clients making the switch from the A-share market in Shanghai. "Who can blame them?" Song said. "Everybody knows the A-share market has been one of the world's worst performers in the past year while other major markets, including Hong Kong, are booming," he said.

"I began buying shares in Hong Kong two years ago after gradually losing confidence in the A-share market, which performed badly and offered quite limited options for investors," said Chen, the electronic parts factory owner.

Chen opened an account and bought shares worth 1 million yuan ($164,000) in the Hong Kong stock market via a financial investment agency.

"The shares I bought were mostly Hong Kong-listed State-owned enterprises, which were all suggested by the financial manager at the agency," said Chen.

From the end of 2011, when the A-share market started declining, some investment agencies in Wenzhou offered local investors the opportunity to buy stocks in Hong Kong.

Some buyers of Hong Kong shares just made use of the dollars they had left over in overseas accounts.