(Adds share price) SHANGHAI, Jan 20 (Reuters) - Alibaba Group founder Jack Ma met 100 rural teachers in China via a live video meeting on Wednesday morning, in the businessman's first appearance since October, triggering a sharp jump in the Hong Kong listed shares of the e-commerce giant. Social media speculation over the whereabouts of China's highest-profile entrepreneur swirled this month after news reports that he missed the final episode of a TV show featuring him as a judge, amid a regulatory clampdown by Beijing on his sprawling business empire. Ma had not appeared in public since Oct. 24, where he blasted China's regulatory system in a speech at a Shanghai forum that set him on a collision course with officials, leading to suspension of a $37-billion IPO of Alibaba's financial affiliate Ant Group.