Binary call option

From Binary Options Trading Wiki

A binary call option is a contract that rewards the holder of the option if the price underlying asset is above the strike price at expiration.

A binary call option is the opposite to a Binary put option,A binary call option is used when the trader believes the he should buy on the belief that the asset price is going to go up. A trader will buy a call contract when he perceives there to be a bull market and/or has a long strategy. A binary call option will settle on a predetermined fixed cash settlement at contract expiration if the expiry price is at above or equal to the strike price . If the strike price is below the expiry price then there will be no payout.
The value of a European binary call option, paying $1 if the underlying asset is above the strike at expiration, in the Black-Scholes world is

e^{-r(T-t)}N(d_{2})