Chinese e-commerce giant Alibaba’s shares plummeted on Tuesday after reports emerged that an individual surnamed “Ma” in the city of Hangzhou was detained on grounds of national security, raising concerns about the company’s founder Jack Ma.The accused was placed under under “compulsory measures” on 25 April on suspicion of “colluding with overseas anti-China hostile forces” to “incite secession” and “incite subversion of state power,” according to China’s state broadcaster CCTV.Alibaba’s Hong Kong-listed shares plunged 9.4 per cent, wiping out about $26bn of market value, after Chinese state media reported the detention of the individual surnamed Ma, reported Bloomberg.Majority of...