MQL4 and MQL5 Programming Articles

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Study the MQL5 language for programming trading strategies in numerous published articles mostly written by you - the community members. The articles are grouped into categories to help you quicker find answers to any questions related to programming: Integration, Tester, Trading Strategies, etc.

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Developing a Replay System (Part 33): Order System (II)

Developing a Replay System (Part 33): Order System (II)

Today we will continue to develop the order system. As you will see, we will be massively reusing what has already been shown in other articles. Nevertheless, you will receive a small reward in this article. First, we will develop a system that can be used with a real trading server, both from a demo account or from a real one. We will make extensive use of the MetaTrader 5 platform, which will provide us with all the necessary support from the beginning.
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Market Simulation (Part 19): First Steps with SQL (II)

Market Simulation (Part 19): First Steps with SQL (II)

As we explained in the first article about SQL, there is no point in spending time programming procedures to do what is already built into SQL. However, without knowing the basics, you won’t be able to do anything with SQL or take full advantage of everything this tool offers. Therefore, in this article, we will look at how to perform basic tasks in databases.
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Brain Storm Optimization algorithm (Part I): Clustering

Brain Storm Optimization algorithm (Part I): Clustering

In this article, we will look at an innovative optimization method called BSO (Brain Storm Optimization) inspired by a natural phenomenon called "brainstorming". We will also discuss a new approach to solving multimodal optimization problems the BSO method applies. It allows finding multiple optimal solutions without the need to pre-determine the number of subpopulations. We will also consider the K-Means and K-Means++ clustering methods.
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Developing an MQTT client for MetaTrader 5: a TDD approach — Part 2

Developing an MQTT client for MetaTrader 5: a TDD approach — Part 2

This article is part of a series describing our development steps of a native MQL5 client for the MQTT protocol. In this part we describe our code organization, the first header files and classes, and how we are writing our tests. This article also includes brief notes about the Test-Driven-Development practice and how we are applying it to this project.
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Mutual information as criteria for Stepwise Feature Selection

Mutual information as criteria for Stepwise Feature Selection

In this article, we present an MQL5 implementation of Stepwise Feature Selection based on the mutual information between an optimal predictor set and a target variable.
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MQL5 Wizard Techniques You Should Know (Part 15): Support Vector Machines with Newton's Polynomial

MQL5 Wizard Techniques You Should Know (Part 15): Support Vector Machines with Newton's Polynomial

Support Vector Machines classify data based on predefined classes by exploring the effects of increasing its dimensionality. It is a supervised learning method that is fairly complex given its potential to deal with multi-dimensioned data. For this article we consider how it’s very basic implementation of 2-dimensioned data can be done more efficiently with Newton’s Polynomial when classifying price-action.
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Hybridization of population algorithms. Sequential and parallel structures

Hybridization of population algorithms. Sequential and parallel structures

Here we will dive into the world of hybridization of optimization algorithms by looking at three key types: strategy mixing, sequential and parallel hybridization. We will conduct a series of experiments combining and testing relevant optimization algorithms.
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Generative Adversarial Networks (GANs) for Synthetic Data in Financial Modeling (Part 2): Creating Synthetic Symbol for Testing

Generative Adversarial Networks (GANs) for Synthetic Data in Financial Modeling (Part 2): Creating Synthetic Symbol for Testing

In this article we are creating a synthetic symbol using a Generative Adversarial Network (GAN) involves generating realistic Financial data that mimics the behavior of actual market instruments, such as EURUSD. The GAN model learns patterns and volatility from historical market data and creates synthetic price data with similar characteristics.
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Ordinal Encoding for Nominal Variables

Ordinal Encoding for Nominal Variables

In this article, we discuss and demonstrate how to convert nominal predictors into numerical formats that are suitable for machine learning algorithms, using both Python and MQL5.
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Market Simulation (Part 02): Cross Orders (II)

Market Simulation (Part 02): Cross Orders (II)

Unlike what was done in the previous article, here we will test the selection option using an Expert Advisor. Although this is not a final solution yet, it will be enough for now. With the help of this article, you will be able to understand how to implement one of the possible solutions.
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Camel Algorithm (CA)

Camel Algorithm (CA)

The Camel Algorithm, developed in 2016, simulates the behavior of camels in the desert to solve optimization problems, taking into account temperature, supply, and endurance. This article also presents a modified version of the algorithm (CAm) with key improvements: the use of a Gaussian distribution in generating solutions and the optimization of the oasis effect parameters.
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The MQL5 Standard Library Explorer (Part 11): How to Build a Matrix-Based Market Structure Indicator in MQL5

The MQL5 Standard Library Explorer (Part 11): How to Build a Matrix-Based Market Structure Indicator in MQL5

Learn to engineer an MQL5 indicator that converts trend, momentum, and volatility into a single raw score using a matrix.mqh (ALGLIB). The article covers a separate‑window oscillator to validate the core mathematics, then a main‑chart indicator that plots non‑repainting buy/sell arrows when the score crosses user‑defined thresholds. An optional long‑term EMA filter, a minimum‑bar cooldown, and built‑in alerts make the tool practical for live trading.
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Category Theory in MQL5 (Part 12): Orders

Category Theory in MQL5 (Part 12): Orders

This article which is part of a series that follows Category Theory implementation of Graphs in MQL5, delves in Orders. We examine how concepts of Order-Theory can support monoid sets in informing trade decisions by considering two major ordering types.
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MQL5 Wizard Techniques you should know (Part 68):  Using Patterns of TRIX and the Williams Percent Range with a Cosine Kernel Network

MQL5 Wizard Techniques you should know (Part 68): Using Patterns of TRIX and the Williams Percent Range with a Cosine Kernel Network

We follow up our last article, where we introduced the indicator pair of TRIX and Williams Percent Range, by considering how this indicator pairing could be extended with Machine Learning. TRIX and William’s Percent are a trend and support/ resistance complimentary pairing. Our machine learning approach uses a convolution neural network that engages the cosine kernel in its architecture when fine-tuning the forecasts of this indicator pairing. As always, this is done in a custom signal class file that works with the MQL5 wizard to assemble an Expert Advisor.
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Market Simulation (Part 09): Sockets (III)

Market Simulation (Part 09): Sockets (III)

Today's article is a continuation of the previous one. We will look at the implementation of an Expert Advisor, focusing mainly on how the server code is executed. The code given in the previous article is not enough to make everything work as expected, so we need to dig a little deeper into it. Therefore, it is necessary to read both articles to better understand what will happen.
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Neural Networks in Trading: Multi-Task Learning Based on the ResNeXt Model (Final Part)

Neural Networks in Trading: Multi-Task Learning Based on the ResNeXt Model (Final Part)

We continue exploring a multi-task learning framework based on ResNeXt, which is characterized by modularity, high computational efficiency, and the ability to identify stable patterns in data. Using a single encoder and specialized "heads" reduces the risk of model overfitting and improves the quality of forecasts.
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Market Simulation (Part 17): Sockets (XI)

Market Simulation (Part 17): Sockets (XI)

The implementation of the part of the code that will run in MetaTrader 5 does not present any difficulty. However, there are several points that need to be taken into account. This is necessary so that you can make the system work. Remember one important thing: not just one program will be running. In reality, we will have to run three programs simultaneously. It is important to implement and structure each of them in such a way that they can interact and communicate with one another, and that each of them understands what the others are trying or intending to do.
All about Automated Trading Championship: Interviews with the Participants'07
All about Automated Trading Championship: Interviews with the Participants'07

All about Automated Trading Championship: Interviews with the Participants'07

The published interviews of Championship 2007 bear the stamp of the results obtained during the preceding contest. The first Championship evoked a wide response on the internet and in printings. The leading developer of the MetaQuotes Software Corp. tells about changes made to the forthcoming Automated Trading Championship 2007. We put our questions to the developer of a well-known indicating complex ZUP, Eugeni Neumoin (nen) and spoke to an equity trader, Alexander Pozdnishev (AlexSilver).
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Applying Localized Feature Selection in Python and MQL5

Applying Localized Feature Selection in Python and MQL5

This article explores a feature selection algorithm introduced in the paper 'Local Feature Selection for Data Classification' by Narges Armanfard et al. The algorithm is implemented in Python to build binary classifier models that can be integrated with MetaTrader 5 applications for inference.
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Artificial Tribe Algorithm (ATA)

Artificial Tribe Algorithm (ATA)

The article provides a detailed discussion of the key components and innovations of the ATA optimization algorithm, which is an evolutionary method with a unique dual behavior system that adapts depending on the situation. ATA combines individual and social learning while using crossover for explorations and migration to find solutions when stuck in local optima.
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Chaos optimization algorithm (COA): Continued

Chaos optimization algorithm (COA): Continued

We continue studying the chaotic optimization algorithm. The second part of the article deals with the practical aspects of the algorithm implementation, its testing and conclusions.
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From Basic to Intermediate: Variables (II)

From Basic to Intermediate: Variables (II)

Today we will look at how to work with static variables. This question often confuses many programmers, both beginners and those with some experience, because there are several recommendations that must be followed when using this mechanism. The materials presented here are intended for didactic purposes only. Under no circumstances should the application be viewed for any purpose other than to learn and master the concepts presented.
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Central Force Optimization (CFO) algorithm

Central Force Optimization (CFO) algorithm

The article presents the Central Force Optimization (CFO) algorithm inspired by the laws of gravity. It explores how principles of physical attraction can solve optimization problems where "heavier" solutions attract less successful counterparts.
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Neural Networks in Trading: Skill Hierarchy for Adaptive Agent Behavior (Final Part)

Neural Networks in Trading: Skill Hierarchy for Adaptive Agent Behavior (Final Part)

The article discusses the practical implementation of the HiSSD framework in algorithmic trading tasks. It explains how the skill hierarchy and adaptive architecture can be used to build sustainable trading strategies.
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Ensemble methods to enhance classification tasks in MQL5

Ensemble methods to enhance classification tasks in MQL5

In this article, we present the implementation of several ensemble classifiers in MQL5 and discuss their efficacy in varying situations.
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From Basic to Intermediate: Operator Precedence

From Basic to Intermediate: Operator Precedence

This is definitely the most difficult question to be explained purely theoretically. That is why you need to practice everything that we're going to discuss here. While this may seem simple at first, the topic of operators can only be understood in practice combined with constant education.
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Analyzing weather impact on currencies of agricultural countries using Python

Analyzing weather impact on currencies of agricultural countries using Python

What is the relationship between weather and Forex? Classical economic theory has long ignored the influence of such factors as weather on market behavior. But everything has changed. Let's try to find connections between the weather conditions and the position of agricultural currencies on the market.
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Neuroboids Optimization Algorithm 2 (NOA2)

Neuroboids Optimization Algorithm 2 (NOA2)

The new proprietary optimization algorithm NOA2 (Neuroboids Optimization Algorithm 2) combines the principles of swarm intelligence with neural control. NOA2 combines the mechanics of a neuroboid swarm with an adaptive neural system that allows agents to self-correct their behavior while searching for the optimum. The algorithm is under active development and demonstrates potential for solving complex optimization problems.
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Leak-Free Multi-Timeframe Engine with Closed-Bar Reads in MQL5

Leak-Free Multi-Timeframe Engine with Closed-Bar Reads in MQL5

The article presents two systematic pitfalls in MQL5 multi‑timeframe work: indicator handle leaks that exhausted resources and repainting from reading the forming bar (index 0). It introduces MTFEngine.mqh, a unified include that creates and tracks handles in one place and defaults all reads to closed bars (index 1). A D1–H4–H1 example shows how this approach keeps signals technically correct and consistent with charts.
All about Automated Trading Championship: Additional Materials of Championships 2006-2007
All about Automated Trading Championship: Additional Materials of Championships 2006-2007

All about Automated Trading Championship: Additional Materials of Championships 2006-2007

We present to you a selection of these materials that are divided into several parts. The present one contains additional materials about automated trading, Expert Advisors development, etc.
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Developing a Replay System (Part 68): Getting the Time Right (I)

Developing a Replay System (Part 68): Getting the Time Right (I)

Today we will continue working on getting the mouse pointer to tell us how much time is left on a bar during periods of low liquidity. Although at first glance it seems simple, in reality this task is much more difficult. This involves some obstacles that we will have to overcome. Therefore, it is important that you have a good understanding of the material in this first part of this subseries in order to understand the following parts.
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Implementing Practical Modules from Other Languages in MQL5 (Part 01): Building the SQLite3 Library, Inspired by Python

Implementing Practical Modules from Other Languages in MQL5 (Part 01): Building the SQLite3 Library, Inspired by Python

The sqlite3 module in Python offers a straightforward approach for working with SQLite databases, it is fast and convenient. In this article, we are going to build a similar module on top of built-in MQL5 functions for working with databases to make it easier to work with SQLite3 databases in MQL5 as in Python.
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Engineering Trading Discipline into Code (Part 7): Automating Equity Protection Through Governance Logic

Engineering Trading Discipline into Code (Part 7): Automating Equity Protection Through Governance Logic

Automated trading systems often focus heavily on signal generation while neglecting the mechanisms required to protect capital during periods of stress. This article presents an Equity Governance Framework in MQL5 that monitors drawdown conditions, evaluates equity pressure, and dynamically controls trading activity through a state-driven risk management model. By combining drawdown analysis, cooldown logic, trade authorization, and execution restrictions, the framework demonstrates how trading discipline can be engineered directly into code using a modular and extensible architecture.
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MQL5 Wizard Techniques you should know (Part 47): Reinforcement Learning with Temporal Difference

MQL5 Wizard Techniques you should know (Part 47): Reinforcement Learning with Temporal Difference

Temporal Difference is another algorithm in reinforcement learning that updates Q-Values basing on the difference between predicted and actual rewards during agent training. It specifically dwells on updating Q-Values without minding their state-action pairing. We therefore look to see how to apply this, as we have with previous articles, in a wizard assembled Expert Advisor.
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Neural Networks in Trading: Reducing Memory Consumption with Adam-mini Optimization

Neural Networks in Trading: Reducing Memory Consumption with Adam-mini Optimization

One of the directions for increasing the efficiency of the model training and convergence process is the improvement of optimization methods. Adam-mini is an adaptive optimization method designed to improve on the basic Adam algorithm.
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Market Simulation (Part 08): Sockets (II)

Market Simulation (Part 08): Sockets (II)

How about creating something practical using sockets? In today's article, we'll start creating a mini-chat. Let's look together at how this is done - it will be very interesting. Please note that the code provided here is for educational purposes only. It should not be used for commercial purposes or in ready-made applications, as it does not provide data transfer security and the content transmitted over the socket can be accessed.
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From Basic to Intermediate: Overload

From Basic to Intermediate: Overload

Perhaps this article will be the most confusing for novice programmers. As a matter of fact, here I will show that it is not always that all functions and procedures have unique names in the same code. Yes, we can easily use functions and procedures with the same name — and this is called overload.
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From Basic to Intermediate: Arrays and Strings (III)

From Basic to Intermediate: Arrays and Strings (III)

This article considers two aspects. First, how the standard library can convert binary values to other representations such as octal, decimal, and hexadecimal. Second, we will talk about how we can determine the width of our password based on the secret phrase, using the knowledge we have already acquired.
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Integrating External Applications with MQL5 Community OAuth

Integrating External Applications with MQL5 Community OAuth

Learn how to add “Sign in with MQL5” to your Android app using the OAuth 2.0 authorization code flow. The guide covers app registration, endpoints, redirect URI, Custom Tabs, deep-link handling, and a PHP backend that exchanges the code for an access token over HTTPS. You will authenticate real MQL5 users and access profile data such as rank and reputation.
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Bivariate Copulae in MQL5 (Part 1): Implementing Gaussian and Student's t-Copulae for Dependency Modeling

Bivariate Copulae in MQL5 (Part 1): Implementing Gaussian and Student's t-Copulae for Dependency Modeling

This is the first part of an article series presenting the implementation of bivariate copulae in MQL5. This article presents code implementing Gaussian and Student's t-copulae. It also delves into the fundamentals of statistical copulae and related topics. The code is based on the Arbitragelab Python package by Hudson and Thames.