The Singapore Exchange said Friday that it will lift trading curbs imposed on three stocks that were drastically volatile in several trading sessions.

The exchange declared on Oct. 4 that the shares of Asiasons Capital, Blumont Group and LionGold were "designated securities" after their share prices shed 61 percent, 56 percent and 42 percent, respectively, in the first hour or so of trading.

The move barred investors from short-selling their shares in the counters and must pay for purchases with cash upfront instead of getting the usual three-day grace period to make payment.

The bourse made the move after failing to get a sound explanation on why the three stocks had accumulated huge gains over the past months.

Nevertheless, the three stocks shed 86 percent, 85 percent and 71 percent, respectively, upon the resuming of trading in their shares on the following Monday on Oct. 7.

The SGX said on Monday that it has decided to lift the curbs as trading in these stocks has since become more stable.

Still, it will continue to monitor the trading of the three stocks and has advised shareholders and investors to trade with caution.

The saga also led some of the investors to call for earlier implementation of the circuit breaker, a mechanism that has a five- minute cooling-off period triggered once the prices of a counter move by more than 10 percent in five minutes. During the cooling- off period, trading can continue, but it must be at or within the 10 percent price band.

The SGX has been considering introducing the circuit breaker mechanism. It said that it will have to get regulatory approval before the dynamic circuit breaker can be introduced. It is expected to be implemented early next year, the bourse said.