He is the co-founder of Hong Kong–based Sun Hung Kai & Co. and was reputed as "King of securities world" and "Godfather of the stock market".
Later he started a small company called Sun Hey, which sells rice, manages hotels and transporting agricultural products through waterway.
In 1958, he founded Eternal Enterprise Company in partnership with Kwok Tak-seng and Lee Shau-kee to develop property business in Hong Kong.
In cooperation with Kwok Tak Seng and Lee Shau Kee, he bought large area of lands and built 20 high-rises within three years.
When the economy recovered, Sung Hung Kai made a huge fortune and the three partners were reputed as the Three Musketeers.