Creating a trading robot for MetaTrader 5 (MT5) involves using MQL5 (MetaQuotes Language 5), a powerful object oriented programming language. These robots, known as Expert Advisors (EAs), can monitor markets and execute trades 24/7 based on your specific logic.
Below is a comprehensive guide to building your first MT5 robot, from strategy design to deployment.
Phase 1: Preparation and Strategy
Before writing a single line of code, you must define brain of your robot. An EA needs three clear sets of rules:
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Entry Logic: What specific conditions must be met to buy or sell? (e.g., a Moving Average crossover).
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Exit Logic: When should trade close? (e.g., hitting a Take Profit or a reversal signal).
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Risk Management: How much of your balance should be risked per trade?
Phase 2: Setting Up Development Environment
MT5 comes with a built-in workshop for coding called MetaEditor.
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Launch MetaEditor: Open MetaTrader 5 and press F4 on your keyboard.
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Start a New Project: Click the “New” button in the top toolbar.
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Use the MQL5 Wizard: Select “Expert Advisor (template)” and click Next. Give your robot a name and click through default event handlers.
Phase 3: Understanding the MQL5 Structure
Every basic EA is built around three core events (functions that trigger at specific times):
| Function | When it runs | Purpose |
OnInit() |
Once, when the EA is loaded. | Used to initialize indicators or check account settings. |
OnDeinit() |
Once, when the EA is removed. | Used to clean up the chart or close files. |
OnTick() |
Every time price moves (a tick). | Most important part. This is where your trading logic lives. |
Phase 4: Coding Your Robot
To make your robot trade, you generally need to follow these steps within the OnTick() function:
1. Get Indicator Data
You must tell robot to look at prices or indicators. For example, if using a Moving Average:
C++
// Create a handle for the indicator
int MA_Handle = iMA(_Symbol, _Period, 50, 0, MODE_SMA, PRICE_CLOSE);
2. Check for Signals
Use an if statement to check if your conditions are met.
C++
if(FastMA > SlowMA) {
// Logic to open a BUY trade
}
3. Execute the Trade
In MQL5, the simplest way to trade is by using CTrade class, which handles complex communication with the broker server.
Phase 5: Testing and Optimization
Never run a new robot on a live account immediately. Use Strategy Tester to see how it would have performed in past.
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Go back to the MT5 platform and press Ctrl+R to open the Strategy Tester.
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Select your EA file (
.ex5). -
Choose a currency pair and a historical timeframe.
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Click Start and review “Graph” and “Backtest” tabs to see your profit, drawdown, and win rate.
Phase 6: Deployment
Once you are happy with backtest results:
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Open Demo Account: Test robot in real-time market conditions without risking real money.
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Enable Algo Trading: Click the Algo Trading button at the top of the MT5 terminal (it should turn green).
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Attach to Chart: Drag your EA from the Navigator window onto a price chart.