John ji the reason i talked about the instrument being just Rs.4 is it is out of the money option, that also on expiry day, If one buys these kind of options then how can one keep a SL in them because i as a rule base my SL on the price of the underlying (Banknifty in this case) This strike price being so far off, even a 10-20 point move in BN would affect it adversely. So if you are going for such low price options, then keep a SL of zero or some time (say 2"o'clock on expiry day) Sell half at double so as to recover your cost.