A MetaTrader 5 Expert Advisor (EA) is a program that automatically executes a trading strategy — without human intervention, 24 hours a day. You set the rules, it applies them without emotion, without fatigue, without forgetting.
But an EA is only as good as the strategy it encodes and the rigor with which it's developed. Here's our method.
Why Code Your Own EA Instead of Buying One
The ready-made EA market (MetaTrader Market, specialized forums) is saturated with products whose backtesting performance doesn't replicate in live trading. The reasons are multiple: overfitting on historical data, excessive parameter optimization, unrepresentative market conditions.
A custom-developed EA built around your strategy has a fundamental advantage: you understand why it makes each decision. You can adjust it, disable it, and identify the conditions under which it shouldn't trade.
The second reason: the source code belongs to you. You can modify it, hand it to another developer, or integrate it into a larger system — with no vendor dependency.
The 4 EA Development Phases
Phase 1 — Strategy Specification (2 to 5 days)
This is the most critical and most underestimated phase. An EA only executes rules — if the rules are vague, the EA will be vague.
We document with you:
- Entry conditions (indicators, price levels, trading sessions)
- Exit conditions (take profit, stop loss, trailing stop, exit on reverse signal)
- Risk management (position size as % of capital, maximum simultaneous trades)
- Filters (exclusion hours, currency pairs, behavior during economic news)
A complete specification document is typically 3 to 5 pages. It serves as the reference throughout development.
Phase 2 — MQL5 Development (1 to 3 weeks depending on complexity)
MetaTrader 5 uses MQL5 — a C-like language dedicated to algorithmic trading. It provides direct access to real-time market data, order management functions, and the built-in strategy tester.
Our development approach:
- Modular structure: clear separation between signal logic, order management, and risk management
- Error handling: every order function call checks the return code and logs errors
- Logging: the EA generates readable logs to facilitate live debugging
- Configurable parameters: all adjustable values (TP, SL, lot size) are inputs exposed in the MT5 interface
Phase 3 — Backtesting and Optimization (1 week)
MetaTrader 5 includes a powerful strategy tester that simulates the EA on historical data with tick-by-tick precision. We systematically use maximum quality data (99% modeling quality).
The metrics we prioritize:
| Metric | What It Measures | Indicative Target |
|---|---|---|
| Profit Factor | Gross gains / Gross losses | > 1.3 |
| Sharpe Ratio | Risk-adjusted return | > 1.0 |
| Max Drawdown | Maximum loss from a peak | < 20% of capital |
| Win rate | Signal reliability | > 45% (depends on R:R ratio) |
| Number of trades | Statistical representativeness | > 200 over the period |
A backtest with a profit factor of 3.5 over 500 trades is more reliable than a result of 2.0 over 50 trades.
What we avoid: excessive parameter optimization (curve fitting). An over-optimized EA performs perfectly on past data and fails live. We always test on an out-of-sample period (not used for optimization).
Phase 4 — Forward Testing and Going Live (2 to 4 weeks)
Before deploying on a real account, the EA runs for two to four weeks on a demo account with real market conditions (real-time spread, connection latency). This is the only way to detect behaviors that don't appear in backtesting: slippage, order rejections, reconnection after network disconnection.
Going live is done progressively: first with minimum lot size, then increasing sizing once the first live trades match expectations.
Classic Mistakes We've Learned From
Not handling slippage. In live trading, orders never execute at exactly the requested price. An EA that doesn't account for slippage can see its performance degrade significantly.
Testing on a single period. An EA that performs in 2019–2020 may fail in 2022–2023 if market conditions have changed. We always test on at least two distinct periods including both trending and ranging markets.
Ignoring weekends. MT5 keeps positions open over the weekend. An EA that doesn't handle this case can be exposed to a significant opening gap on Monday.
What Does EA Development Cost?
A simple EA (one strategy, one currency pair, no martingale or complex logic): €400 to €900.
A multi-strategy or multi-pair EA with a supervision dashboard: €900 to €2,500.
The price includes specification, development, documented backtesting, forward testing, and delivery of the commented MQL5 source code.
Your Strategy, Automated
If you have a trading strategy you apply manually — and you spend too much time watching charts — we can encode and test it for you. Describe your entry and exit logic, and we'll tell you whether it's feasible and at what budget.