The price reaction follows information from the Reuters news agency that the company is about to be added to the Trump administration's blacklist of Chinese military companies, the so-called 1260H list.
An update to the list, with Alibaba among the designated companies, could come as early as Friday, Reuters reports, citing two sources.
A company that ends up on the list would face severe restrictions on its operations in the United States, where the group operates several trading platforms for businesses and consumers.
