HONG KONG (AP) — The Hong Kong stock exchange has halted trading of Next Digital shares at the media company’s request after assets belonging to its founder, Jimmy Lai, were frozen. Later Monday, the media tycoon and nine pro-democracy activists pleaded guilty to taking part in an unlawful assembly. Lai is already in prison for his role in two other unauthorized assemblies in 2019 when Hong Kong experienced mass anti-government protests. Next Digital publishes pro-democracy tabloid Apple Daily, and Lai is its controlling shareholder. The 10 who pleaded guilty face up to five years’ imprisonment at sentencing next week. Lai is under investigation for allegedly endangering national security and his assets were frozen under a new national security law Beijing imposed on the city.