An expert advisor is simply a piece of code written in the MQL4 programming language which, once installed on your MetaTrader 4 Forex trading platform, has the ability to automate the opening and closing of trades on your behalf. It is a piece of code that includes a set of rules based on what, how and when to trade. It also allows you to adjust stop loss, take profit and trailing stop levels according to pre-defined parameters.

Every expert advisor is different. Every EA – its own animal. But they all serve the same purpose: to eliminate inconsistency – a fault that characterizes most traders.

How An Expert Advisor Works

Once installed and enabled to run, an EA will usually first check if there is enough equity in your account to open a trade. If there isn’t, it won’t run.

If there is enough equity in your account, the EA will on each tick of the currency pair(s) that it is assigned to trade on, run through it’s rules and codes and verify that the trade entry criteria have been met. Alternatively, if open trades already exist, it will check that an exit (stop-loss or take-profit) criteria has occurred. If it has, it will automatically exit the trade for you.

To work, the computer that is running your expert advisor (and trading platform) must be kept running all the time while the forex market is open. If you ensure that your computer is running 24×5 – all you have to do is sit back, relax and let it do its thing!

Programming a Strategy Into The Expert Advisor

An expert advisor can be designed to trade many different strategies. They can include grid strategies, hedging strategies, martingale and reverse martingale strategies, trend following strategies, correlation strategies – you name it. Additionally, you can choose to combine one or more strategies together.

Forex expert advisors can trade breakouts, news announcements only or they can be scalping expert advisors which aim to secure small profits as soon as they are available. An expert advisor can be programmed to do whatever you like – the possiblilities are truly limitless.

Classic EA’s look to trade bounces off of support and resistance and reversals. They enter trades when a high probability setup looks like occurring. Many expert advisors come with trailing stop losses – a feature which helps you lock in profits.They can also be programmed to monitor market conditions for reversals and then close your trade immediately when these conditions are met to lock in profits as well.

More advanced EA’s can trade multiple pairs simultaneously or monitor multiple timeframes at once, giving you a wide range of options in picking a market trend – something that would take you hours if you had to do it manually.

The type of EA you choose to trade with should sit well with your overall trading style. Playing around with its risk-settings while it is trading live will give you a better feel for what it does well and you will learn it’s characteristics better. If you understand what it is doing, you will have more confidence in it to ride out a bad performing patch while you continue to monitor and play with its stop-loss and take-profit levels.

While the point of forex expert advisors is to automate your trading decisions and improve trading consistency by taking emotions out of your trading, you still must pay attention to what the expert advisor is doing. This is especially relevant if your expert advisor is automatically set at a wide stop-loss of say 100 pips or more.

Conclusion

Understanding the strengths and weaknesses of your Forex Expert Advisor is paramount if you intend to trade with them in live market conditions and with real money. There are various different types of Expert Advisors available today for the Mt4 platform and they are restricted only by the creativity of the programmers who design them.