The BSE today said trading would halt for the day if the benchmark index Sensex moves up or down 20%, or 3,475 points, in a single day in the July-September quarter.
According to a statement by BSE, market circuit breakers would be triggered at three stages of the index movement either way at 10%, 15% and 20%.
The statement added that market wide circuit breakers would be triggered by the movement of either Sensex or the NSE S&P CNX Nifty whichever is breached earlier.
In case of a 10% or 1,750 points movement either way before 1 pm, there would be a one—hour market halt. If it is after 1 pm but before 2.30 pm, the halt is for half an hour. There will be no trading halt, if Sensex or Nifty moves 10% up or down at or after 2.30 pm.
In case of a 15% movement or 2,625 points in index before 1 pm, there will be a two—hour market halt. If the 15% trigger level is reached on or after 1 pm but before 2 pm, there will be a halt of an hour. If this trigger is reached on or after 2 pm, the trading will be halted for the remainder of the day.
Further, in case of a 20%, or 3,475-point, movement of the index, the trading will be halted for the remainder of the day, it said.
The said percentages are calculated on the closing index value of the quarter. These percentages are then translated into absolute points of index variations.
At the end of each quarter, these absolute points of index variations are revised and made applicable for the next quarter, BSE said.
On June 29, 2012, the last trading day of the quarter, Sensex closed at 17,429.98 points.
The absolute points of Sensex variation which would trigger market wide circuit breaker for any day in the quarter between July 1, 2012 and September 30, 2012 would be 10% (1,750 points), 15% (2,625 points) and 20% (3,475 points), BSE said.