In Internet you can find free of charge or buy for little money a great number of mechanical systems which according to their authors will bring you tens or even hundreds percent of income per month. Most of such «Grails» show very good results when they are tested on historical data but on demo-accounts and live-accounts such systems fail. The point is that it is very easy to write Expert Advisors — mechanical trading systems for MetaTrader 4 — any trader is able to do this. That’s why a great number of such unprofessional «frobs» containing a number of mistakes has appeared in Internet.
By this post I start a series of articles on how to write one’s own expert advisor, how to avoid common mistakes which distort the real profitability of a mechanical trading system etc.
At first let’s define what is an Expert Advisor:
Expert Advisor is an algorithm of executing trades and managing orders programmed in MetaQuotes Language 4 by a trader.
Of course one can trade on his account manually, but for example in Alpari several tens of currency pairs plus tens of other instruments: CFD on the US stocks, commodity futures etc. - are offered. Just fancy how long it will take you to analyze each instrument. Very often a situation emerges when in an instrument a signal to open a position forms but you miss this favorable moment as you are busy analyzing another instrument. Besides you can’t help sleeping or eating. But you can miss a signal to enter into a transaction when you sleep.
There are much more reasons to entrust managing of your account to someone who will do this 24 hours a day, 5 days a week, being emotionless at the same time (as emotions severely impact successful trading). To someone who is able to monitor on-line ALL instruments. To someone who will act precisely in accordance with the algorithm programmed by you. And this invaluable helper is an Expert Advisor or in other words a trading algorithm programmed in the MetaQuotes Language 4.
Everything mentioned above sounds promising and optimistic. But it isn’t so easy. An Expert Advisor does precisely what you order. If your trading strategy is originally loss-making, your Expert Advisor will trade online according to your algorithm not missing a single chance to execute a trade and thus it may bring your trading account to a sorry plight.
But if your trading strategy is profitable quite soon you may become more prosperous. In the textbook on writing expert advisors on our website you will know not only how to write an expert advisor by yourself but also how to test it properly on historical data.
