SHANGHAI:Alibaba Group founder Jack Ma made his first appearance since October on Wednesday when he spoke to a group of teachers by video, easing concern about his unusual absence from public life and sending shares in the e-commerce giant surging.

Speculation over Ma's whereabouts has swirled in the wake of news this month that he was replaced in the final episode of a reality TV show he had been a judge on, and amid a regulatory clampdown by Beijing on his sprawling business empire.

The billionaire, who commands a cult-like reverence in China, had not appeared in public since Oct. 24, when he blasted China's regulatory system in a speech at a Shanghai forum. That set him on a collision course with officials and led to the suspension of a blockbuster $37 billion IPO for Alibaba's financial affiliate Ant Group.

Alibaba and his charitable foundation both confirmed he participated in an online ceremony for an annual event for rural teachers on Wednesday.

In the 50-second video, Ma, wearing a navy pullover, spoke from a room with grey walls, a large painting and floral arrangements. It was not clear where the room was.

Alibaba's Hong Kong-listed shares jumped over 10% on the news, which was first reported by Tianmu News, a media outlet backed by the government of Zhejiang, the province where Alibaba's headquarters are based.

"Jack Ma's reappearance has given investors peace of mind after a lot of rumours, allowing them to pile into the stock which had been a laggard in the market," said Steven Leung, sales director at brokerage UOB Kay Hian in Hong Kong.

The topic "Jack Ma makes his first public appearance" and his video address to the teachers soon began trending on China's Twitter-like Weibo, triggering heavy discussion.

Although Ma has stepped down from corporate positions and earnings calls, he retains significant influence over Alibaba and Ant and promotes them globally at business and political events. He also continues to mentor management talent in the "Alibaba Partnership", a 35-member group of company managers.

China has stepped up a regulatory crackdown on anticompetitive behaviour in the internet sector and Alibaba became the target of an antitrust investigation launched last month by Chinese authorities.

The company plans to raise at least $5 billion through the sale of a U.S. dollar-denominated bond this month.