The automated system of the Thai stock market even had to bring in measures to suspend trading (Circuit Breaker: CI) to temporarily stop stock trading in order to quell panic and give those involved time to check the information before the situation escalates out of control. After 12:18 p.m., the Thai stock index dropped to 1,348.99 points, down 117.52 points or -8.01%, with a trading value of 95,248.82 million baht.
Mechanisms and Rules: Breaking Points in 3 Levels The Stock Exchange of Thailand (SET) has designed the Circuit Breaker measure to work automatically when the SET Index drops to a specified level. Currently (2026), this measure is divided into 3 levels as follows:
Level 1: When the index drops 8%, the market pauses all securities trading for 30 minutes to allow investors to breathe and reassess the situation.
Level 2: If the market after opening continues to fall by 15%, the market will pause trading again for 30 minutes.
Level 3: Worst case If the index drops 20%, the market will pause trading for up to 60 minutes.
Over the past 20 years, the Thai stock market has faced a crisis situation that required the use of Circuit Breakers a total of 6 times.
1st time (19 Dec. 2006): Caused by the “30% reserve measure” of the Bank of Thailand. To prevent speculation on the value of the baht This caused foreign investors to panic and sell stocks until the index dropped more than 100 points in one day. Until it received the nickname “Black Tuesday”
2nd time (10 Oct. 2008): Occurs during “Hamburger Crisis” when giant financial institutions like Lehman Brothers went bankrupt, affecting liquidity and the global economy.
3rd time (27 Oct 2008): Just a few weeks later. The market is still pressured by concerns about the US economic crisis. It will spread into a global recession.
4th time (12 Mar. 2020): The COVID-19 epidemic crisis is starting to get more serious around the world. In addition, the price of crude oil plummeted heavily. causing investors to flock to sell risky assets all over the world at the same time
5th time (13 Mar. 2020): Just one day after the 4th time, the market immediately dropped 10% until trading had to be stopped since the morning. This is the first time that this measure has been used for two consecutive days.
6th time (23 March 2020): Concerns about the lockdown and the economic impact of the COVID-19 outbreak continue to exert heavy pressure until the index falls to the trigger point level again before the Circuit Breaker threshold is adjusted.
