An anomaly of mainland China’s technology boom is that Chinese are often unable to invest in the companies behind innovations. While the biggest firms make profits locally, they raise capital through being listed on stock markets beyond everyday people’s reach. President Xi Jinping has lamented that peculiarity, rightly saying citizens should be able to share the growth benefits of the nation’s tech champions. Alibaba, the world’s largest online shopping platform, aims to correct that through plans to add a primary listing in Hong Kong to its New York presence. Alibaba, which owns this newspaper, has had a secondary listing in...