The landmark Shanghai-Hong Kong Stock Connect, linking both stock exchanges, has gone live on 17 November, facilitating stock trades worth billions of dollars between the mainland and the city state.
The scheme has also partially opened up China's equities markets to international investors.
"Shanghai-Hong Kong Stock Connect marks the first time international investors will be able to directly access China's biggest stock market in Shanghai, and only through HKEx," the exchange said on its website.
"It's a significant breakthrough in the opening of China's capital market, giving investors a wide range of new investment possibilities."
The scheme connects the Shanghai and Hong Kong stock markets, allowing investors on both sides to trade and settle shares in each other's market. It has been designed to maximise the benefits of a free and open market while maintaining strong risk management standards, the exchange said.
Trading through the link is running smoothly, and investors from Hong Kong have spent significantly on mainland share purchases, Bloomberg reported citing brokerages such as First Shanghai Financial Holding Ltd. and Emperor Securities Ltd.
While international investors purchased 13bn yuan ($2.1bn, £1.4bn, €1.7bn) of Shanghai shares, triggering a halt in buy orders for the rest of the day, mainland investors used about 1.4bn yuan of their 10.5bn yuan quota in Hong Kong.
The securities regulators of both Hong Kong and China earlier approved the trading link. Linking the two bourses will effectively create the world's third largest equity market with a $5.6tn single market capitalisation, behind the New York Stock Exchange and Nasdaq and ahead of London and Tokyo, according to Allianz Global Investors.
Announced by Chinese premier Li Keqiang in April, Stock Connect will allow global investors, institutional and retail, to trade Shanghai "A" shares via the Hong Kong stock exchange while Chinese mainland investors will be able to trade Hong Kong "H" shares via the Shanghai Stock Exchange for the first time.
Hong Kong Exchanges and Clearing Chief Executive Charles Li had earlier said that the scheme has a long-term strategic significance to both mainland and Hong Kong and would help China's internationalisation of the yuan. It will help contribute to Hong Kong's prosperity in the next 10 to 20 years.