Hong Kong (CNN Business) Investors are falling over themselves to buy into Alibaba's debut on the Hong Kong stock market.

China's biggest e-commerce company will stop taking orders from retail investors for its $13 billion share sale later on Tuesday after seeing stronger-than-expected demand, a person familiar with the matter told CNN Business.

Hang Seng Index HSI The enthusiasm is a vote of confidence in the Asian financial hub, which has been rocked by months of civil unrest . Thefell 4.8% last week as the city grappled with escalating levels of violence. So far this week, the index has gained 2.9% despite a further escalation in violence centered around the siege of a university.

Alibaba will close its order books on Tuesday at 12 p.m. ET in New York, half a day earlier than originally planned, the person said. The plan was first reported by Reuters

The Hong Kong listing was "multiple times subscribed," the person said, adding that the final price retail investors will pay for the Hong Kong listing will be based on Alibaba's closing price Tuesday in New York, where its shares have been traded since 2014.