Expert Advisor (EA)

An Expert Advisor is an automated trading program, written in MetaTrader's MQL4 or MQL5 programming language, that can analyze charts and place, modify, or close trades according to pre-programmed rules without manual intervention. EAs range from simple tools that just manage an open trade's stop-loss to fully autonomous systems that generate their own entry signals. An EA is only as reliable as its underlying logic and how it was tested — a strategy that looks excellent in a backtest can still fail live if it was over-optimized to historical data (curve fitting) rather than built on a genuinely robust edge.