Two firms listed on the Singapore Exchange (SGX) were queried by the bourse over "substantial" share price falls on Monday.
Ossia International, a regional distributor and retailer of fashion, accessories and sporting goods, was queried after it fell as much as 26 per cent to 25.5 cents in the first hour of trading. The counter later narrowed the loss by recovering to 44 cents as at 11.30am.
Ossia responded within an hour of the SGX query to say it was not aware of any information or any other possible explanation for the trading.
The other counter that was queried was Asia-Pacific Strategic Investments, which provides bereavement services in the region.
Its share price was down almost 30 per cent at one point to 20.5 cents, but rose later in the morning to 25 cents, a drop of 12 per cent from Friday's close.