A PUT option is an option the underlying market price of that is expected to fall. When a trader expects the markets price of the underlying to come down, he has to choose a PUT option. When the market price of the underlying at the expiry is lower than at the moment of purchase, 70% profit no matter how much the market price falls, even though it is just 0.001. When the market price is the same as at the moment of purchase, the trader gets back the whole amount of his investment.