In the money refers to the situation when your prediction is correct and the price at the expiration is above or below the strike price, according to your trade direction. For a Higher option, in the money means that the price is above the strike price at expiry time. When it comes to Lower contracts, in the money will occur if the current price is below the strike price.

Examples of the In the Money Situation

To better understand how it works, it is worth looking at a couple of examples. You decide to buy a Higher contract for BTC/USD at 119,000 as a strike price. The expiration time is set to 5 minutes. The trade will be in the money if the current price at expiration is above 119,000 or at least 119,001. 

If you want to buy a Lower contract for Tesla at 355 as the strike price with 1 1-minute expiration, then the in-the-money situation will occur if the price moves below the strike price at expiry. 

Briefly speaking, in the money means that your trade is profitable, and your profit will be calculated as payout*investment amount.