MQL4 and MQL5 Programming Articles

Let us reveal a little secret: MQL5.com website visitors spend most of their time on Johnpaul77 signal's page. It is a leader of our signal rating having about 900 subscribers with the total funds of $5.7 million on real accounts. We have interviewed the signal's providers. As it turned out, there are four of them! How are duties distributed among the team members? What technical tools do they use? Why do they call themselves John Paul? And finally, how have common gamers from Indonesia become providers of the top signal on MQL5.com? Find out all that in the article.

On the occasion of the MQL5 Freelance Service fourth birthday, we have prepared an info-graphic demonstrating the service results for the entire time of its existence. The figures speak for themselves: more than 10 000 orders worth about $600,000 in total have been executed to date, while 3 000 customers and 300 developers have already used the service.

MQL5 Freelance is an online service where developers get paid for creating trading applications ordered by traders. Now, traders understand the difference between all the services on MQL5.com: a ready-made Trading Robot can be bought from the MetaTrader Market, while a unique Expert Advisor that trades based on a specific user-defined strategy can be ordered in the Freelance service. Experienced developers compete for traders' order implementation, so that a trader can select the one who offers the best time and cost conditions. Since the launch of the service, traders have paid a total of $600,000 for 10,000 jobs performed

Algorithmic trading becomes more popular and needed, which naturally led to a demand for exotic algorithms and unusual tasks. To some extent, such complex applications are available in the Code Base or in the Market. Although traders have simple access to those apps in a couple of clicks, these apps may not satisfy all needs in full. In this case, traders look for developers who can write a desired application in the MQL5 Freelance section and assign an order.

Today we will learn how to link an MetaTrader 5 terminal with Twitter so that you can tweet your EAs' trading signals. We are developing a Social Decision Support System in PHP based on a RESTful web service. This idea comes from a particular conception of automatic trading called computer-assisted trading. We want the cognitive abilities of human traders to filter those trading signals which otherwise would be automatically placed on the market by the Expert Advisors.

The article describes an example of Renko charting and its implementation in MQL5 as an indicator. Modifications of this indicator distinguish it from a classic chart. It can be constructed both in the indicator window and on the main chart. Moreover, there is the ZigZag indicator. You can find a few examples of the chart implementation.

A short life span of futures contracts complicates their technical analysis. It is difficult to technically analyze short charts. For example, number of bars on the day chart of the UX-9.13 Ukrainian Stock index future is more than 100. Therefore, trader creates synthetic long futures contracts. This article explains how to splice futures contracts with different dates in the MetaTrader 5 terminal.

From August 1, 2014, MetaTrader 4 desktop terminals older than build 600 will no longer be supported. However, many traders still work with outdated versions and are unaware of the updated platform's features. We have put a lot of effort into development and would like to move on with traders and abandon the older builds. In this article, we will describe the advantages of the new MetaTrader 4.

In this article, we will consider the development of a multi-symbol indicator to analyze price divergence in a specified period of time. The core topics have been already discussed in the previous article on the programming of multi-currency indicators "MQL5 Cookbook: Developing a Multi-Symbol Volatility Indicator in MQL5". So this time we will dwell only on those new features and functions that have been changed dramatically. If you are new to the programming of multi-currency indicators, I recommend you to first read the previous article.

Two years ago in "The Last Crusade" we reviewed quite an interesting yet currently not widely used method for displaying market information - point and figure charts. Now I suggest you try to write a trading robot based on the patterns detected on the point and figure chart.

This article is intended for developers who would be interested in using SQL in their projects. It explains the functionality and advantages of SQLite. The article does not require special knowledge of SQLite functions, yet minimum understanding of SQL would be beneficial.

To avoid critical completion of programs, the previous version compiler handled many errors in the runtime environment. For example, division by zero or array out of range are critical errors and usually lead to program crash. The new compiler can detect actual or potential sources of errors and improve code quality. In this article, we discuss possible errors that can be detected during compilation of old programs and see how to fix them.

The new version of the MetaTrader 4 terminal features the updated structure of user data storage. In earlier versions all programs, templates, profiles etc. were stored directly in terminal installation folder. Now all necessary data required for a particular user are stored in a separate directory called data folder. Read the article to find answers to frequently asked questions.

There is currently a fair number of means for a comfortable remote monitoring of a trading account: mobile terminals, push notifications, working with ICQ. But it all requires Internet connection. This article describes the process of creating an Expert Advisor that will allow you to stay in touch with your trading terminal even when mobile Internet is not available, through calls and text messaging.

The new version of the programming language for trading strategy development, MQL [MQL5], provides more powerful and effective features as compared with the previous version [MQL4]. The advantage essentially lies in the object-oriented programming features. This article looks into the possibility of using complex custom data types, such as nodes and lists. It also provides an example of using lists in practical programming in MQL5.

MetaTarder 4 build 600 features the new structure and location of the client terminal files. Now, MQL4 applications are placed in separate directories according to the program type (Expert Advisors, indicators or scripts). In most cases, the terminal data is now stored in a special data folder separated from the terminal installation location. In this article, we will describe in details how data is transferred, as well as the reasons for introducing the new storage system.

Updated MQL4 has the new format for storing historical data and provides the appropriate MqlRates structure for convenient storage of Time, Open, Low, High, Close and Volume values. For many years, traders have developed their MQL4 applications that collect and store their data in HST files for generating offline charts. We can assure you that all previously compiled EX4 files will work in the new MetaTrader 4 terminal the same way as before.

The article describes one of the approaches to determining a useful signal (trend) in stream data. Small filtering (smoothing) tests applied to market quotes demonstrate the potential for creating non-lagging digital filters (indicators) that are not redrawn on the last bars.

In this article, we will consider the development of a multi-symbol volatility indicator. The development of multi-symbol indicators may present some difficulties for novice MQL5 developers which this article helps to clarify. The major issues arising in the course of development of a multi-symbol indicator have to do with the synchronization of other symbols' data with respect to the current symbol, the lack of some indicator data and the identification of the beginning of 'true' bars of a given time frame. All of these issues will be closely considered in the article.

The article proposes Kagi chart indicator with various charting options and additional functions. Also, indicator charting principle and its MQL5 implementation features are considered. The most popular cases of its implementation in trading are displayed - Yin/Yang exchange strategy, pushing away from the trend line and consistently increasing "shoulders"/decreasing "waists".

The article introduces a structure for an Expert Advisor that trades multiple symbols and uses several trading systems simultaneously. If you already identified the optimal input parameters for all your EAs and got good backtesting results for each of them separately, ask yourself what results you would get if testing all EAs simultaneously, with all your strategies put together.

In just 15 minutes, this video tutorial explains what MetaTrader Signals Service is, and demonstrates in great detail how to subscribe to trade signals and how to become a signal provider in our service. By watching this tutorial, you will be able to subscribe to any trading signal, or publish and promote your own signals in our service.

The article provides a detailed description of the process of testing and optimizing Expert Advisors in the MetaTrader 4 Strategy Tester. The importance of such information and the need for this publication cannot be underestimated. A lot of users who only get started with the MetaTrader 4 trading platform have a very vague idea of what and how needs to be done when working with Expert Advisors. The proposed article gives simple and clear answers to all of these questions and provides a slightly more professional approach to handling these issues using a specific example.

In this article, the author continues to familiarize the readers with the Lite_EXPERT2.mqh functions using real Expert Advisor implementation examples. The article deals with the idea of using floating pending orders and pending orders that vary dynamically from deal to deal which are determined based on Average True Range (ATR) indicator values.

The article deals with the automatic system for analyzing any trading account in MetaTrader 4 terminal. Technical aspects of a generated report and interpretation of the obtained results are considered. Conclusions on improving trading factors are drawn after the detailed review of the report. MQLab™ Graphic Report script is used for analysis.

This article is a continuation and development of my previous article "Visual Testing of Profitability of Indicators and Alerts". Having added some interactivity to the parameter changing process and having reworked the study objectives, I have managed to get a new tool that does not only show the prospective trade results based on the signals used but also allows you to immediately get a layout of deals, balance chart and the end result of trading by moving virtual sliders that act as controls for signal parameter values in the main chart.

Today's article shows intermediate MQL5 programmers how they can get more profit from their linear trading systems (Fixed Lot) by easily implementing the so-called technique of exponentiation. This is because the resulting equity curve growth is then geometric, or exponential, taking the form of a parabola. Specifically, we will implement a practical MQL5 variant of the Fixed Fractional position sizing developed by Ralph Vince.

Let's continue exploring various controls and this time turn our attention to scrollbar. Just like in the previous article entitled "MQL5 Cookbook: Indicator Subwindow Controls - Buttons", all operations will be performed in the indicator subwindow. Take a moment to read the above mentioned article as it provides a detailed description of working with events in the OnChartEvent() function, while this point will only be casually touched upon in this article. For illustrative purposes, this time around we will create a vertical scrollbar for a large list of all financial instrument properties that can be obtained using MQL5 resources.

In this article, we will consider an example of developing a user interface with button controls. To convey the idea of interactivity to the user, buttons will change their colors when the cursor hovers over them. With the cursor being over a button, the button color will be slightly darkened, getting significantly darker when the button is clicked. Furthermore, we will add tooltips to each button, thus creating an intuitive interface.

There are 21 time frames available in MetaTrader 5 for analysis. You can take advantage of special chart objects that you can place on the existing chart and set the symbol, time frame and some other properties right there. This article will provide detailed information on such chart graphical objects: we will create an indicator with controls (buttons) that will allow us to set multiple chart objects in a subwindow at the same time. Furthermore, chart objects will accurately fit in the subwindow and will be automatically adjusted when the main chart or terminal window is resized.

In this article, we will consider such issues as including sound files in the file of the Expert Advisor, and thus adding sound notifications to trade events. The fact that the files will be included means that the sound files will be located inside the Expert Advisor. So when giving the compiled version of the Expert Advisor (*.ex5) to another user, you will not have to also provide the sound files and explain where they need to be saved.

In this article, technical indicators are treated as digital filters. Operation principles and basic characteristics of digital filters are explained. Also, some practical ways of receiving the filter kernel in MetaTrader 5 terminal and integration with a ready-made spectrum analyzer proposed in the article "Building a Spectrum Analyzer" are considered. Pulse and spectrum characteristics of the typical digital filters are used as examples.

MQL5 provides programmers with a very complete set of functions and object-oriented API thanks to which they can do everything they want within the MetaTrader environment. However, Web Technology is an extremely versatile tool nowadays that may come to the rescue in some situations when you need to do something very specific, want to marvel your customers with something different or simply you do not have enough time to master a specific part of MT5 Standard Library. Today's exercise walks you through a practical example about how you can manage your development time at the same time as you also create an amazing tech cocktail.

We continue the series of articles on MQL5 programming. This time we will see how to get results of each optimization pass right during the Expert Advisor parameter optimization. The implementation will be done so as to ensure that if the conditions specified in the external parameters are met, the corresponding pass values will be written to a file. In addition to test values, we will also save the parameters that brought about such results.

This article continues the series of articles "Expert Advisors Based on Popular Trading Systems and Alchemy of Trading Robot Optimization". It familiarizes the readers with a more universal function library of the Lite_EXPERT2.mqh file.

Another quarter of the year has passed and we have decided to sum up its results for MetaTrader AppStore - the largest store of trading robots and technical indicators for MetaTrader platforms. More than 500 developers have placed over 1 200 products in the Market by the end of the reported quarter.

The article describes a method of modifying the code of a trading signal module for the implementation of the functionality allowing you to set pending orders at any distance from the current price: it may be the Close or Open price of the previous bar or the value of the moving average. There are plenty of options. Important is that you can set any opening price for a pending order. This article will be useful to traders who trade with pending orders.

Whatever trading strategy you use, there will always be a question of what parameters to choose to ensure future profits. This article gives an example of an Expert Advisor with a possibility to optimize multiple symbol parameters at the same time. This method is intended to reduce the effect of overfitting parameters and handle situations where data from a single symbol are not enough for the study.

Developing a system of SMS notifications that informs you of the status of your EA so that you are always aware of any critical situation, wherever you may be.

It is possible to start making money on MQL5.com right now without having to be a seller of Market applications or a profitable signals provider. Select the products you like and post links to them on various web resources. Attract potential customers and the profit is yours!