New Delhi, June 18 -- Shareholders selling equity in the National Stock Exchange of India Ltd (NSE) public offer are set to bag up to thousand-fold returns on their average investment costs once the exchange gets listed.

For this analysis, Mint has used the approximate upper and lower ends of grey-market quotes as references, which price shares at Rs.1,800 on the lower end and Rs.2,040 on the upper end. At the higher end, the exchange will be valued at over Rs.5 trillion.

To be sure, grey market prices are not mathematically calculated, and final price bands are set by merchant banks after accounting for multiple factors.

New India Assurance Co. and National Insurance Co. hold the lowest entry basis among the selling group, with a weig...