It is the circuit breaker system which bring a trading halt on all equity and equity derivatives markets across the exchange. It applies at three stages of the index movement either way at 10%, 15% and 20%.The breakers are triggered by movements in either Nifty or Sensex, whichever is breached earlier.

*In case of a 10% movement in either of these indices, there would be a one-hour market halt if the movement takes place before 1:00 p.m. In case the movement takes place at or after 1:00 p.m. but before 2:30 p.m. there would be trading halt for ½ hour. In case movement takes place at or after 2:30 p.m. there will be no trading halt at the 10% level and market would continue trading.

*In case of a 15% movement of either index, there should be a two-hour halt if the movement takes place before 1 p.m. If the 15% trigger is reached on or after 1:00 p.m. but before 2:00 p.m., there should be a one-hour halt. If the 15% trigger is reached on or after 2:00 p.m. the trading should halt for remainder of the day.

*In case of a 20% movement of the index, trading should be halted for the remainder of the day.

The exchanges implements the index based market wide circuit breaker system on a quarterly basis. At the end of each quarter, these absolute points of index variations are revised and made applicable for the next quarter.