A binary option is a financial product where the parties involved in the transaction are assigned one of two outcomes based on whether the option expires in the money. Binary options depend on the outcome of a "yes or no" proposition, hence the name "binary." Binary options have an expiry date and/or time. At the time of expiry, the price of the underlying asset must be on the correct side of the strike price (based on the trade taken) for the trader to make a profit.