Introduction of Pre Open Session by Exchanges
Introduction of Pre Open Session by Exchanges
Pursuant to circulars CIR/MRD/DP/21/2010 dated July 15, 2010 and CIR/MRD/DP/32/2010 dated September 17, 2010 for introduction of Call Auction process in Pre Open Session, the exchanges have decided to introduce call auctions in pre open session with effect from October 18, 2010. The call auction in pre-open session will be introduced initially for securities forming part of indices CNX Nifty and SENSEX.
Taking the above into consideration please note that normal market for Equity and Futures & Option will open at 9:15am instead of 9:00am from October 18, 2010
What is the Pre Open session?
It is basically a mechanism to determine the Opening Price based on aggregated supply and demand for the underlying.
What are the timings for the Pre Open session?
The session would commence for 15 minutes between 9:00am and 9:15am out of which order placement in the Pre Open session would be allowed for the first 7 /8 minutes only.
Click here for a detailed explanation /FAQ on the Pre Open session from BSE

why did they introduce Pre -open session ???