Where is Jack Ma? Chinese tycoon not seen since October

Alibaba co-founder has fallen out of favour with Beijing, but observers cautious about drawing conclusions

Speculation is mounting over the whereabouts of the Chinese billionaire Jack Ma, who has not been seen or heard in public for more than two months.

Ma, the co-founder and former chairman of the technology firm Alibaba, has fallen out of favour with China's leadership. In late October, he stood alongside senior officials and delivered a blunt speech criticising national regulators, reportedly infuriating China's president, Xi Jinping.