What Is a Forex EA? A Practical Beginner’s Guide
Understand what an Expert Advisor does, how it differs from an indicator, and what to check before running a forex robot.
EA technology & forex knowledge
Practical guides to EA source code, MT5 testing and the trading mechanics behind a forex robot.
From source file to a repeatable test
Start here if you have an editable EA and want to work through it in order.
The guide library
10 guidesMQ4 vs EX4 and MQ5 vs EX5: What Are You Buying?
Learn the difference between editable EA source, compiled programs, includes and SET files before choosing an MT4 or MT5 package.
How to Compile MQL5 Source Code in MetaEditor
Build an MQ5 project into an EX5, check dependencies and diagnostics, and confirm which executable you are testing.
How to Backtest an EA in MT5: A Repeatable Workflow
Set up an MT5 baseline test, choose a tick mode, inspect individual events and save enough evidence to repeat the result.
How to Read an EA Backtest Report Beyond Net Profit
Use worked examples to understand win rate, profit factor and drawdown, and ask better questions about an EA backtest.
EA Overfitting: What Forward Testing Can and Cannot Tell You
Separate parameter selection from evaluation, preserve an untouched period, and distinguish historical forward tests from demo observation.
XAUUSD Contract Size, Tick Value and Lot Size Explained
Read a gold symbol’s contract specifications and understand how units, volume and account currency affect a position-size calculation.
Forex Spread, Slippage and Commission: The EA Cost Checklist
Compare trading costs with a worked example, avoid double counting and document execution assumptions in an EA test.
MT5 EA Not Trading? Diagnose It Step by Step
Distinguish missing signals, permission problems and rejected trade requests, then prepare a support report that can be reproduced.
Buying EA Source Code: A Practical Pre-Purchase Checklist
Check editable files, dependencies, release identity, testing evidence, licence terms and support before buying EA source code.
About these guides
MQLume publishes software education and forex-mechanics guides. Articles are prepared with AI assistance and reference linked primary documentation; translations are assisted by Google Translate and edited for terminology. Worked examples are illustrative, not results from our products. We sell source-code packages, so product links are commercial links to our own store.
Educational information only. This is not investment advice or a recommendation to trade. Forex and leveraged derivatives involve substantial risk. Backtest and demo-test software before considering live use; past results do not guarantee future performance.