Sichuan Em Technology (SHA:601208) experienced abnormal stock fluctuations over three consecutive trading days, but it said its operations remain entirely normal, according to a Shanghai bourse filing on Friday.
The electrical insulation materials maker's closing share price rose by more than 20% between June 2 and June 4, exceeding the threshold set by the Shanghai bourse.
The company's probe found it has no announcements that could constitute unusual share movement.
Em's shares fell nearly 3% during the midday trade.