New Martin EA v1.1 Source Code MQ4 for MetaTrader 4 (MT4) is an Expert Advisor (EA) typically designed to use martingale-style trading strategies. Martingale strategies are often used to recover losses by increasing the trade size after a losing position, with the intention of turning profits once a winning trade is achieved. This EA version is likely designed to automate that process and handle it more efficiently, according to specific rules and parameters.