Definition of 'Anti-Martingale System'
A system of position sizing that correlates the levels of investment with the risk and portfolio size. An anti-Martingale strategy involves halving your bets each time you lose a trade, and doubling them each time you win a trade.
Investopedia explains 'Anti-Martingale System'
The assumption of the anti-Martingale system is you can capitalize on a winning streak by doubling your position. In contrast, a Martingale strategy requires the trader to double his bet each time he loses, and hope to eventually recover those losses and make a profit with a favorable bet. The anti-Martingale system accepts greater risks during periods of expansive growth and is considered a better system for online traders, because it is less risky to increase trade size during a winning streak, than during a losing streak.
The anti-Martingale system, along with the Martingale system and speculation, is one of three basic ways for forex traders to bet on the market.