On Wednesday, shares of Chinese solar power manufacturer Hanergy Thin Film were suspended after falling 47%, wiping out $18.6bn (Â£11.9bn) from its market capitalisation.
That was followed by shares of Goldin Financial, which fell 55% on Thursday.
Both firms had seen the price of their shares surge over the past year.
Shares of Goldin Financial, which is 70%-owned by Hong Kong billionaire Pan Sutong, have jumped by more than 400% between September 2014 and March this year, according to Reuters.
The firm had said that it was not aware of the reason behind the big jump in its share price.
About half of Goldin's value - $16.12bn - was erased on Thursday as shares fell.
Meanwhile, Hanergy shares had risen five-fold since September before the sell-off began.
The firm, controlled by Chinese billionaire Li Hejun, had issued a statement to the Hong Kong Stock Exchange on Wednesday saying its shares had been halted from trade "pending the release of an announcement containing inside information".
Li has been considered one of China's richest men on the back of his stake in Hanergy.
Nicholas Teo, market analyst at trading firm CMC markets said he had noticed the dramatic drop in Hanergy's shares right away because it had everyone "scratching their heads".
"The company was very quick to call a halt to the trading, but without any news, there is plenty of speculation and potentially room for further reaction to the downside if the trading suspension is lifted," he said.
"Even after the drop though, Hanergy's shares are basically twice as expensive as some of the firms in that sector."
David Kuo, chief executive of The Motley Fool Singapore backed the view that Hanergy shares were overvalued.
"Hanergy is involved in the much-hyped solar-panel industry. Investors are paying $50 for every dollar of profit the company makes," he said.
"When expectation overtakes reality, reality eventually wins. The market is experiencing a dose of reality."
There has been speculation as to the reason why the Chinese company halted trading, with Reuters citing an unnamed source as saying the firm is under investigation by Hong Kong regulators.
Hong Kong's Securities and Futures Commission (SFC) has declined to make a comment.
Local reports also said that Li, chairman of the firm, did not attend the firm's annual general meeting in Hong Kong on Wednesday.
Shares of two Hong Kong-listed companies have plunged by about 50% in the past two days, surprising market watchers across the region.