Some very important decisions by the company needed to be made regarding which country that they wish to use for the floatation of the company. Alibaba could have chosen a country closer to home, like Hong Kong, but they have chosen to float the company on the American stock market, because the owner of the company doesn’t lose the rights to the company in an American floatation, unlike Hong Kong.
The system that is used in Hong Kong works for them, but many big companies aren’t choosing to use the Hong Kong markets and preferring to take their business elsewhere. The numbers of large companies, meaning companies that are worth over $4 billion, are choosing other stock markets. Hong Kong hasn’t had a company this large float on the stock market since 2010.