Alibaba's $10 billion buyback plan fails to stop sell-off

Shares of Alibaba in Hong Kong plunged on Monday to their lowest level since June as worries mount over a regulatory crackdown by the Chinese government on co-founder Jack Ma's e-commerce and financial empire.

The company saw its shares get pummeled for the second straight session in a sell-off that has knocked almost $116 billion off the tech giant's Hong Kong-listed shares.

That came despite Alibaba on Monday announcing it was increasing its share buyback program from $6 billion to $10 billion.

What would've been good news for investors failed to ease their concerns after Chinese regulators announced last week the launch of an antitrust probe into Alibaba and said they would summon its fintech affiliate, Ant Group to meet.

Putting investors more on edge was news over the weekend that China's central bank had asked Ant to shake up its lending and other consumer finance operations.

Last month, Chinese regulators abruptly suspended Ant's blockbuster $37 billion initial public offering in Shanghai and Hong Kong, which was on track to be the world's largest, just two days before its planned debut.

Alibaba's U.S. listed shares were down briefly in Monday morning trade.