Summary: The Martingale Strategy states that when a trader experiences a loss, they should immediately double the size of the next bet. By repeatedly doubling the bet when they lose, the trader will theoretically even out with a winning trade at some point.

A martingale is a class of betting strategies that originated from and were popular in 18th-century France. The simplest of these strategies was designed for a game in which the gambler wins the stake if a coin comes up heads and loses if it comes up tails.