How to write an Expert Advisor for MetaTrader 4

The dynamic development of the market and constant advances in computer technology force traders to keep up with the times. While writing expert advisors to suit their trading strategy was once seen as a whim to simplify a trader's life, it's now more of a necessary measure to remain competitive in this market.

Yes, competitive, because robots have completely taken over the exchange. While pipsing and scalping strategies were once easy to apply manually, now it's quite difficult to remain effective against the backdrop of high-speed robots.

Therefore, sooner or later, each of us asks ourselves a completely logical question: “How to write an advisor for MetaTrader 4?”.

To write an advisor for MetaTrader 4 or any other platform, you must first have programming knowledge. Our experience shows that each platform has its own programming language, which can be easily learned using the program's textbook.

However, not everyone can master programming due to personal incompetence or lack of time. Therefore, we most often employ the services of programmers or use an expert advisor builder.

How to write an advisor yourself?

Naturally, if you're unfamiliar with programming, you can use various builders. Typically, all builders separate important functions into blocks, so all work with the program boils down to combining these blocks based on your trading strategy.

Incidentally, we previously provided an example of how to use and create an Expert Advisor for MetaTrader 4 using the Forex Strategy Builder . The advantage of using this program is that it is fully localized, making it easy for almost anyone involved in trading to use.

Preparing technical specifications for a programmer

Often, the difficulty of writing an advisor isn't a lack of programming knowledge, but rather the simple difficulty of expressing your own wishes. Whether you write the advisor yourself or commission one from a programmer, if you can't clearly lay out the strategy's rules on paper, you'll never get what you want.

Therefore, to get exactly what you want from the contractor, you need to clearly lay out your requirements. So, let's start from the beginning.

1. Inform that the advisor will be used for real trading.

This point may seem ridiculous, but the MT4 strategy testing advisor is typically very different from the actual trading advisor. If you don't clearly specify this, you may end up with an advisor that won't open positions in real time or won't track its orders if the connection is lost.

You must understand that these two types of experts differ greatly in terms of labor intensity, so if you do not clearly indicate this, the programmer may take the easiest path of resistance.  

2. Specify the rules for entering a position.

Clear entry rules are crucial for a programmer writing an Expert Advisor. Don't forget about simple details like entering on a closed candle or on a signal, and setting a pending order based on the current price or a closed candle.

All these childish mistakes lead to the programmer finishing everything as he wants, and in the end this can greatly affect the result.

Also, remember that the contractor may be at a completely different level of trading, so avoid using jargon. Always back up your suggestions with a picture, and remember that the words "mashka" and " moving average " may have different meanings for the contractor, even though you're talking about a moving average.

3. Specify the algorithm for exiting the position

Traders often forget to specify this point, so their experts close and open positions when a signal appears in the opposite direction, or, conversely, don't react to market changes until a stop-loss or profit is triggered. Pay special attention to this point, because if you don't specify it upfront, no one will redesign your expert advisor for free.

4.    Rules for calculating positions and supporting transactions.

If you are used to seeing that almost every expert advisor has a trailing stop or calculates the lot depending on the risk percentage, this does not mean that the programmer will do the same.

Remember, whether you're writing your own advisor using a builder or assigning it to a programmer, your primary goal is to carefully consider every element of your strategy, down to the last detail.