Shares of Next Digital ballooned 344 percent to HK$0.40 during afternoon sessions, hitting its highest since June last year. The rally came after the stock retreated 17 percent in pre-market trading to reach a new record low – and moments after the arrest of Apple Daily founder, Jimmy Lai.

Hong Kong-based Apple Daily newspaper is owned by media mogul Lai. The tabloid-like paper is Next Digital's most popular business.

The rally came as Lai's supporters took to social media to lobby support for the stock after Hong Kong police arrested him on Monday under China's new security law. Lai, a pro-democracy cruasader, is facing charges of colluding with foreign forces.

Lai is the most prominent figure to be arrested so far under Beijing's new legislation. If found guilty of his crime, Lai can face a life in prison.

Analysts have yet to determine what caused the stocks strong advance. An acquisition of more than 1 million shares of Next Digital generated over 5,000 likes and 300 shares on one Facebook post.

UOB Kay Hian (Hong Kong) Ltd. executive director Steven Leung commented that so-called institutional investors are certainly not the ones purchasing Next Digital's stock, referring to comments on the social media post. 

Apple Daily, now viewed by many as the remaining media group that has consistently resisted China's Communist Party, may stop existing at any moment, HenryPorterBabel, a Facebook page with over 39,000 followers, wrote. HenryPorterBabel said it was purchasing 300,000 Next Digital shares.

Pro-democracy legislator Shiu Ka-chun wrote that he will buy a copy of Apple Daily on Tuesday even if it's "a pile of blank papers.

Other local media shares in Hong Kong also made a surprise ascent during Monday's trade. Among them is One Media Group Ltd, whose shares surged nearly 50 percent to HK$0.24. The stock is a Chinese translation of Next Digital's corporate identity.