The reopening of Chinese stock markets on Friday after a week-long hiatus will give them their first litmus test. Share prices are set to show whether the disappearance of the former "bagman" to families of Communist party leaders forces his powerful backers to liquidate their holdings. Others are speculating on a renationalisation of assets held by Mr Xiao or his Tomorrow Group.
The 45-year-old financier has not appeared in public since he left his Hong Kong residence in the early hours last Friday, accompanied by Chinese security agents. He later told his family he was in mainland China, according to people familiar with the investigation.
Mr Xiao liked to style himself a value investor and disciple of Warren Buffett. But his primary asset seemed to be an ability to make himself useful when China's powerful families needed to move money around. Shell companies he controlled were instrumental in several deals involving families of Chinese leaders. These include the 2006 privatisation of Luneng Group, a state-owned power company in Shandong that was later renationalised, and the 2013 sale of a stake in Ping An Insurance.
In recent days the previously censored 2006 story of the Luneng privatisation by the family of Zeng Qinghong, a politician allied with Jiang Zemin, the former president, has been allowed to circulate freely on social media in China. Its resurrection is seen as a sign of larger political motives behind his repatriation.
His known investments stretched from chemical plants and coal mines near his wife's hometown in Inner Mongolia to property ventures and Ping An.