A Geopellys stock price fell more than 60% on Tuesday after a tweet by a senior employee of a major Chinese company was reported by media.
The tweet was a call for investors to buy the company, and said that the stock price would go up by 30% in two months.
On Wednesday, the tweet was deleted and the company denied that the tweet had been sent by the employee.
It added that the employee had been given a notice of termination.
The employee was also given the option to appeal against the dismissal.
The stock price has fallen by more than 40% in the last two months, according to data compiled by Bloomberg.
The company did not immediately respond to a request for comment.