MT5 Expert Advisor Development: MQL5 Guide for Beginners

MetaTrader 5 (MT5) is the most widely used platform for forex and commodity trading, and Expert Advisors (EAs) are the backbone of automated trading on it. Here is what you need to know. What is an Expert Advisor? An EA is a script written in MQL5 that runs directly inside MT5 and can open, manage, and close trades automatically based on your defined logic. It runs 24/7 as long as MT5 is open — or on a VPS. MQL5 Basics MQL5 is similar to C++ in syntax. Every EA has three core functions: OnInit() runs once when the EA starts, OnTick() runs on every new price tick, and OnDeinit() runs when the EA is removed. Your strategy logic lives in OnTick(). Building a Simple Moving Average EA A basic EA might check whether a fast EMA crosses above a slow EMA. If it does, open a buy order. If it crosses below, open a sell order. Add a stop-loss and take-profit to every order, and wrap it in position-sizing logic based on account balance. Backtesting in MT5 MT5 has a built-in Strategy Tester that lets you run your EA on historical data with tick-by-tick accuracy. Always optimize your parameters on out-of-sample data — not just the period you backtested on. Deployment on VPS For 24/7 operation, deploy your MT5 instance on a Windows VPS. Low-latency VPS providers near broker servers (like those in London or New York) will give you faster execution. Team NAK builds custom MT5 EAs in MQL5 for forex, gold, and indices. Visit theteamnak.com/contact to discuss your strategy.