An Expert Advisor — usually shortened to EA — is a program that runs inside the MetaTrader platform and places, modifies, or closes trades according to rules written in code. That is the entire definition. It is not a prediction machine, it is not artificial intelligence in any meaningful sense of the word, and it is not a license to stop paying attention to your account.
The rules inside an EA can be as simple as "buy when the 50-period moving average crosses above the 200-period average" or elaborate enough to fill thousands of lines: session filters, news-time blackouts, position-sizing formulas, recovery logic, and dozens of configurable inputs. But structurally, every EA is the same thing — a loop that wakes up on every price tick or every new bar, evaluates its conditions, and either acts or does nothing.
Why automation exists at all
Manual traders fail for well-documented, boring reasons: they hesitate on valid setups, they revenge-trade after losses, they widen stops mid-trade, and they can't watch charts around the clock. Automation removes the human from the moment of execution. The strategy still has to be good — automation does not create an edge, it only enforces one consistently.
That distinction is the most important sentence in this entire curriculum. A profitable rule set executed automatically stays profitable. An unprofitable rule set executed automatically simply loses money with perfect discipline, faster and around the clock.
What an EA can and cannot see
An EA sees exactly what the platform gives it: price history, current quotes, its own open positions, account balance and margin, and the clock. It does not see tomorrow's news, central-bank decisions, or the order books of major banks. Strategies that work do so by exploiting repeatable structure — session behavior, volatility patterns, mean reversion, momentum persistence — not by seeing the future.
This is also why identical EAs produce different results on different accounts. Broker spreads, commission, execution speed, and even server time zones change what the code experiences. Two people running the same robot with the same settings can and do get different outcomes. Lesson five covers this in detail.
The questions to ask about any EA
You do not need to read code to be a competent operator of automated strategies. You do need honest answers to these five questions — from the developer, from the documentation, or from your own testing. The rest of this curriculum teaches you how to get those answers yourself.
Commercial EAs come from many places: the MetaTrader Market, independent developers, and companies that build them as products — including AL-ai-FX, the company behind this site. The source changes nothing about the method: every robot, ours included, deserves the same questions about rules, risk, and evidence before it touches a live account.
- What are the entry and exit rules, in plain language? If the seller cannot explain them, walk away.
- How does it size positions, and what is the maximum loss per trade and per day?
- What happens in abnormal conditions — spread spikes, gaps, disconnections, margin calls?
- What data was it tested on, and does that data include unfavorable periods?
- What does it do when the strategy stops working — and how would you even notice?