In the event of an unsuccessful trade, you increase the amount of the following trade to cover the losses. As soon as your trade closes successfully, you go back to the original trade amount and start over.
For example, you open a trade for $1, and your forecast is incorrect. Next you open a trade for $2, and it fails again. Then you increase the trade amount to $5, and your forecast proves accurate. This way, you recover the losses of previous trades and earn extra profit.
The Martingale method usually contains four to seven steps. If step seven was a losing trade, it is recommended to stop trading activity for the day.