In the event of the stock index fall exceeding 10 per cent on a given trading day, the market’s circuit breakers will be activated to temporarily halt trading. The SET circuit breakers were triggered twice in 2008 and trading halted for 30 minutes after the SET Index dropped more than 10 per cent on October 10 amid political protests.The circuit breaker was also activated on October 27 for another 30 minutes due to negative effects from the US 2008 sub-prime crisis, which led to a six-year low for Thai stock prices.