Grinm Advanced Materials (SHA:600206) said it experienced an abnormal stock fluctuation for three consecutive trading days, but its operations remain normal, according to a Shanghai bourse filing on Saturday.
The advanced materials manufacturer's shares jumped 9% at the close of Monday's trade.
The company's closing stock price 20% of the bourse's threshold between June 24 and June 26.
The company's probe found that there is no significant announcement that could have affected its stock price.