In the money

From Binary Options Trading Wiki

There are two possible outcomes when binaries can be [[in_the_money_binary_option| In the money]

1)binary call option

Binary Call option will be in the money in case the price during expiry is higher then the strike price,
the price the option was purchased.
Let's say you bought Apple Binary call option at a price of $99,
at the end of the hour, Apple price surpassed the $99.2 level.
In that situation the [[binary_call_option|Binary call option] expired In the money paying the full predetermined payout.

2)binary put option

Binary Put option will be in the money in case the price during expiry is lower then the strike price,
the price the option was purchased.
Let's say you bought Apple Binary put option at a price of $99,
at the end of the hour, Apple price plunged below the $98.9 level.
In that situation the Binary put option expired In the money paying the full predetermined payout.

At-the-money is one of three possible states of trading options, the other two are Out of the money binary options (OTM) and At the money(ATM)