After months of speculation about his whereabouts, China's richest man, Jack Ma, has resurfaced in a short online video praising China's teachers. It's the first time the co-founder of tech titan Alibaba has been seen in public since October, when Ma blasted China's regulators during a speech at a forum in Shanghai. Those comments set him on a collision course with Beijing officials and led to the abrupt suspension of the IPO of Ant Group, the payments firm he controls. The blockbuster listing had been set to be the largest ever before it was abruptly pulled in November. Weeks later, Ma skipped the filming of a TV talent show he created for African entrepreneurs. His absence led to media reports and speculation that he was missing. Wednesday's reappearance by Ma has driven a sharp jump in Alibaba's shares. In the video, he praises 100 teachers and tells them we will meet again when the health crisis is over. According to local reports, the online event was the Jack Ma Rural Teachers Award ceremony. His physical whereabouts were not disclosed. Ma's video came as Alibaba now faces an antitrust investigation by Chinese regulators.