The Singapore Exchange said on Thursday morning that shareholders and potential investors should exercise caution when dealing in the securities of mainboard-listed United Envirotech.

SGX said the trade with cautuin was issued after United Envirotech responded on Thursday to say it was not aware of any reasons that could possibly explain the trading in its securities.

The exchange regulator had queried the company on 29 October regarding the substantial increase in its share price by 13.51 per cent between 28 October and 29 October 2014.

The stock was down 1 cent at $1.46 on opening Thursday.