## Comment on STT Trap - Options Expiry - NSE BSE MCX-SX

nifty closing price is calculated by weighted average of nifty in last half an hour 03.00 pm to 03.30 pm ( source – nse )

how to calculate nifty closing price by weighted average ??

what is exact formula to calculate weighted average of last half an hour ?? what includes in formula ? ( price ,volume or time ?? )