If in six months the market crashes by 20% (500 points on the index), he or she has made 250 points by being able to sell the index at $2250 when it is trading at $2000—a combined loss of just 10%. In fact, even if the market drops to zero, the loss would only be 10% if this put option is held. Again, purchasing the option will carry a cost (the premium), and if the market doesn’t drop during that period, the maximum loss on the option is just the premium spent.

The Problem arises if one party fails to perform. The trader may fail to sell if the prices of steel goes very high like for example INR 40,000 in January 2017, in that case, he may not be able to sell at INR 31,000. On the other hand, if the buyer goes bankrupt or if the price of steel in January 2017 goes down to INR 20,000 there is an incentive to default. In other words, whichever way the price moves, both the buyer and seller have an incentive to default.
An option is a contract that allows (but doesn't require) an investor to buy or sell an underlying instrument like a security, ETF or even index at a predetermined price over a certain period of time. Buying and selling options is done on the options market, which trades contracts based on securities. Buying an option that allows you to buy shares at a later time is called a "call option," whereas buying an option that allows you to sell shares at a later time is called a "put option."