Index Computation
Indicative values for all BSE indices will be calculated and disseminated at regular intervals during the order entry period. Post order entry, the indicative index will incorporate the opening price(s) of the stock(s) as and when determined to compute actual opening value. In the absence of the indicative price, the previous closing price of the stock will be used. Once the opening price of all SENSEX 30 stocks is determined, The real index will be calculated and displayed.

Risk Management
Margins & Collateral: In the order entry period (9:00-9:08) of the pre open session, upfront margins will be adjusted against the available collateral of members on a cumulative quantity basis at the time of entering the orders. In other words, orders will not be accepted in the system if the member does not have adequate collateral. In case of cancellation of orders, the blocked margins will be released immediately during this period.

During the order matching and confirmation period of the pre open session (from 9:08 onwards), all the order level blocked margins will be released and actual trade level margins will be blocked based on the trades generated.

The current risk management system for cash market (i.e. blocking of upfront margins at the trade level) shall continue to be applicable to the continuous trading session from 9:15am – 3:30pm.

Price Bands: A uniform price band of 20% will be applicable to all eligible securities during the pre open session.

Circuit Filters: In the event the Index breaches its prescribed threshold imit upon calculation of the opening value of SENSEX, a trading halt (market wide circuit breakers) will be triggered as per current practice (SEBI Circular Ref. No. SMDRPD/Policy/Cir-37 /2001 dated June 28, 2001). The halt shall be applicable at the start of the continuous trading session. The index breach will not impact the execution and confirmation of trades during the pre-open matching session.