Starting from October 18, 2010, the exchanges shall accept orders in equity cash segment for selected scrips before markets open. This mechanism, known as Call Auction is introduced to smoothen the volatility in the stock prices due to overnight developments, if any. This will also help investors in the process of better price discovery.
The SEBI circular comes into effect from Monday, October 18, 2010, wherein selected NIFTY and SENSEX scrips will be available for order placement in pre-open session which will last for 15 minutes from 9.00 a.m. to 9.15 a.m. The orders you place would be accumulated for first 8 minutes of this session. Based on the maximum executable quantity the exchanges will determine the discovery price. Opening price determination, order matching and trade confirmation will happen in the next 4 minutes. The last 3 minutes would be for transition from pre-open to normal trading session