Shares in Chinese bubble-tea chain Baicha Baidao plunged nearly 40 percent on its first trading day in Hong Kong on Tuesday, in a fresh blow to the finance hub's efforts to revive its markets.

The Chengdu-based company, which is also known as Chabaidao, raised about HK$2.59 billion (US$330 million) during its November initial public offering -- with no others topping it since.

But soon after opening it plunged from its HK$17.50 listing price to HK$10.80, marking a drop of 38 percent, before paring some of the losses to end at HK$12.80.

The plunge marked the worst debut since 2015 for a company that had raised at least US$300 million, according to Bloomberg.

Another debutant, Tianjin Construction Development Group, tanked more than 30 percent, having raised about US$20 million in its IPO.

The losses dealt a blow to the government's plan to help reboot Hong Kong's trading market, which has seen a drop in fundraising through new listings for four years in a row.

But Hong Kong's security chief-turned-city leader John Lee told reporters Tuesday that five new measures announced last week by China's securities regulator would help boost sentiment.

They include allowing more funds -- such as Hong Kong's real estate investment trusts -- to undertake cross-border trading, and supporting leading Chinese companies to list in the city.