The Singapore Exchange (SGX) suspended trading in the shares of Blumont, Liongold and Asiasons Capital within minutes of each other, just one hour after the market opened on Friday.
The suspensions come shortly after the SGX issued queries to the three companies to ask them to explain a sudden large decrease in their share prices.
"SGX-ST has exercised its authority to temporarily suspend trading in the shares of Blumont Group and its related securities with immediate effect," the bourse said.
"This is to safeguard the interests of the market as there could be circumstances that would result in the market not being fully informed."
In its single hour of trading on Friday morning, Blumont plunged 56 per cent, losing almost $2 billion in market value, while Asiasons lost 61.5 per cent and Liongold crashed 42.1 per cent.
Three other counters - Innopac Holdings, ISR Capital and ISDN Holdings - were queried by the SGX on Friday morning as well.
As of 10.10 am, Innopac sank 44.2 per cent, ISR tumbled 37.9 per cent and ISDB was down 18.1 per cent.