The circuit breaker system is applicable at three stages if the Sensex or Nifty moves either way at 10 per cent, 15 per cent and 20 per cent. This circuit breaker brings a halt to all equity and equity derivative markets nationwide.
10 per cent: There is one-hour market break in trading, if it happens before 1 pm. After 1 pm and before 2.30 pm, there will be a halt for one and a half hours. After 2.30 pm, the market will continue trading.
15 per cent: There will be a two-hour market halt, if the movement takes place before 1 pm. After 1 pm and before 2 pm, there is a one-hour halt. After 2 pm, the trading will stop for the remainder of the day.
20 per cent: No trading for the rest of the day.
Importantly, the percentages are calculated on the closing index value of the quarter (rounded off to the nearest 25 points for the Sensex)। At the end of March 31, 2009, the last trading day of the quarter, the Sensex closed at 9708.50 points.
So in terms of percentage:
10 per cent = 975 points
15 per cent =1,450 points
20 per cent = 1,950 points
Sensex rose 2,110.79 points = 21.74 per cent
