Max pain is the price at which option buyers would loss the most money, and option writers (sellers) would profit the most. This page will have the Options Max Pain Calculator for Nifty and Bank Nifty. Options Max Pain calculates outstanding open interest at any point of time and calculates max pain. The theory suggests that before expiration the underlying stock moves to a point where there is a maximum loss to option buyers. Before reaching a conclusion it presumes the following. Buyers of option lose money mostly. Sellers are the institutional players or hedge funds who hedge their position by selling options. Sellers are big players who can induce the underlying to move to a point where the option buyers lose money mostly creating maximum pain for the option buyers.