For instance, if you might bet that the share price of X Company will be above $15 on July 10th at 3pm, and you buy one binary call option for $50 with a predetermined payout of $100. If, at 3pm on July 10th, the share price of X Company is $16, then you will be paid $100 for a $50 profit. If the share price was $14, then you would lose your $50.
A binary option is a financial exotic option in which the payoff is either some fixed monetary amount or nothing at all. The two main types of binary options are the cash-or-nothing binary option and the asset-or-nothing binary option. The former pays some fixed amount of cash if the option expires in-the-money while the latter pays the value of the underlying security. They are also called all-or-nothing options, digital options (more common in forex/interest rate markets), and fixed return options (FROs) (on the American Stock Exchange).