Trading on the Thai stock market was halted after the bourse plunged 8% on Monday, triggering the circuit-breaker under the new securities trading regulations.
It is only the sixth time in history -- but the third time this year -- that a circuit breaker has been activated to curb excessive volatility in the Thai equities market.
The SET index fell 90.19 points, or 8%, to 1,037.05 points in turnover of 46.2 billion baht as of 3.30pm local time.
Trading was to resume at 3.55pm, with the pre-open session starting at 3.45 pm.
A circuit-breaker is triggered in three stages. In the first stage, equity trading is halted for 30 minutes if the SET index falls by 8%, down from the previous 10%. Trading is halted for an additional 30 minutes if the SET index plunges by 15%, a change from a 60-minute intermission for a 20% decline.
If the SET index continues falling to reach a 20% drop for the day, trading is halted for 60 minutes in the third stage.
The revised regulations are effective from Monday until June 30.