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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Neural Networks in Trading: Transformer for the Point Cloud (Pointformer)

Neural Networks in Trading: Transformer for the Point Cloud (Pointformer)

In this article, we will talk about algorithms for using attention methods in solving problems of detecting objects in a point cloud. Object detection in point clouds is important for many real-world applications.
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From Basic to Intermediate: Indicator (IV)

From Basic to Intermediate: Indicator (IV)

In this article, we will explore how to easily create and implement an operational approach for coloring candles. This concept is highly valued by traders. When implementing such things, care must be taken to ensure that the bars or candles retain their original appearance and do not hinder reading candle by candle.
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From Basic to Intermediate: Passing by Value or by Reference

From Basic to Intermediate: Passing by Value or by Reference

In this article, we will practically understand the difference between passing by value and passing by reference. Although this seems like something simple and common and not causing any problems, many experienced programmers often face real failures in working on the code precisely because of this small detail. Knowing when, how, and why to use pass by value or pass by reference will make a huge difference in our lives as programmers. The content presented here is intended solely for educational purposes. Under no circumstances should the application be viewed for any purpose other than to learn and master the concepts presented.
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Animal Migration Optimization (AMO) algorithm

Animal Migration Optimization (AMO) algorithm

The article is devoted to the AMO algorithm, which models the seasonal migration of animals in search of optimal conditions for life and reproduction. The main features of AMO include the use of topological neighborhood and a probabilistic update mechanism, which makes it easy to implement and flexible for various optimization tasks.
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Economic forecasts: Exploring the Python potential

Economic forecasts: Exploring the Python potential

How to use World Bank economic data for forecasts? What happens when you combine AI models and economics?
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From Basic to Intermediate: Array (III)

From Basic to Intermediate: Array (III)

In this article, we will look at how to work with arrays in MQL5, including how to pass information between functions and procedures using arrays. The purpose is to prepare you for what will be demonstrated and explained in future materials in the series. Therefore, I strongly recommend that you carefully study what will be shown in this article.
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Developing a Replay System (Part 29): Expert Advisor project — C_Mouse class (III)

Developing a Replay System (Part 29): Expert Advisor project — C_Mouse class (III)

After improving the C_Mouse class, we can focus on creating a class designed to create a completely new framework fr our analysis. We will not use inheritance or polymorphism to create this new class. Instead, we will change, or better said, add new objects to the price line. That's what we will do in this article. In the next one, we will look at how to change the analysis. All this will be done without changing the code of the C_Mouse class. Well, actually, it would be easier to achieve this using inheritance or polymorphism. However, there are other methods to achieve the same result.
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From Basic to Intermediate: IF ELSE

From Basic to Intermediate: IF ELSE

In this article we will discuss how to work with the IF operator and its companion ELSE. This statement is the most important and significant of those existing in any programming language. However, despite its ease of use, it can sometimes be confusing if we have no experience with its use and the concepts associated with it. The content presented here is intended solely for educational purposes. Under no circumstances should the application be viewed for any purpose other than to learn and master the concepts presented.
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From Basic to Intermediate: Struct (I)

From Basic to Intermediate: Struct (I)

Today we will begin to study structures in a simpler, more practical, and comfortable way. Structures are among the foundations of programming, whether they are structured or not. I know many people think of structures as just collections of data, but I assure you that they are much more than just structures. And here we will begin to explore this new universe in the most didactic way.
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Mastering Model Interpretation: Gaining Deeper Insight From Your Machine Learning Models

Mastering Model Interpretation: Gaining Deeper Insight From Your Machine Learning Models

Machine Learning is a complex and rewarding field for anyone of any experience. In this article we dive deep into the inner mechanisms powering the models you build, we explore the intricate world of features,predictions and impactful decisions unravelling the complexities and gaining a firm grasp of model interpretation. Learn the art of navigating tradeoffs , enhancing predictions, ranking feature importance all while ensuring robust decision making. This essential read helps you clock more performance from your machine learning models and extract more value for employing machine learning methodologies.
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Tabu Search (TS)

Tabu Search (TS)

The article discusses the Tabu Search algorithm, one of the first and most well-known metaheuristic methods. We will go through the algorithm operation in detail, starting with choosing an initial solution and exploring neighboring options, with an emphasis on using a tabu list. The article covers the key aspects of the algorithm and its features.
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Gaussian Processes in Machine Learning: Regression Model in MQL5

Gaussian Processes in Machine Learning: Regression Model in MQL5

We will review the basics of Gaussian processes (GP) as a probabilistic machine learning model and demonstrate its application to regression problems using synthetic data.
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Mastering Log Records (Part 6): Saving logs to database

Mastering Log Records (Part 6): Saving logs to database

This article explores the use of databases to store logs in a structured and scalable way. It covers fundamental concepts, essential operations, configuration and implementation of a database handler in MQL5. Finally, it validates the results and highlights the benefits of this approach for optimization and efficient monitoring.
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Statistical Arbitrage Through Cointegrated Stocks (Final): Data Analysis with Specialized Database

Statistical Arbitrage Through Cointegrated Stocks (Final): Data Analysis with Specialized Database

The article shows how to pair SQLite (OLTP) with DuckDB (OLAP) for statistical arbitrage data processing. DuckDB’s columnar engine, ASOF JOIN, and array functions accelerate core tasks such as quote–trade alignment and RWEC, with measured speedups from 2x to 23x versus SQLite on larger inputs. You get simpler queries and faster analytics while keeping trade execution in SQLite.
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Integrating MQL5 with Data Processing Packages (Part 6): Merging Market Feedback with Model Adaptation

Integrating MQL5 with Data Processing Packages (Part 6): Merging Market Feedback with Model Adaptation

In this part, we focus on how to merge real-time market feedback—such as live trade outcomes, volatility changes, and liquidity shifts—with adaptive model learning to maintain a responsive and self-improving trading system.
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Position Management: Safe Pyramiding with a Unified Stop in MQL5

Position Management: Safe Pyramiding with a Unified Stop in MQL5

This article presents CPyramidEngine, a reusable MQL5 class that adds disciplined pyramiding to any Expert Advisor with about six lines of integration. The engine enforces three constraints: strictly decreasing lot sizes, a single unified stop that advances after each add-on, and broker-level validation of every modification. It explains common failure modes in naive implementations and shows how to keep total account risk quantifiable and controlled as positions are added.
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MQL5 Wizard Techniques you should know (Part 70):  Using Patterns of SAR and the RVI with a Exponential Kernel Network

MQL5 Wizard Techniques you should know (Part 70): Using Patterns of SAR and the RVI with a Exponential Kernel Network

We follow up our last article, where we introduced the indicator pair of the SAR and the RVI, by considering how this indicator pairing could be extended with Machine Learning. SAR and RVI are a trend and momentum complimentary pairing. Our machine learning approach uses a convolution neural network that engages the Exponential kernel in sizing its kernels and channels, 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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Integrating MQL5 with data processing packages (Part 3): Enhanced Data Visualization

Integrating MQL5 with data processing packages (Part 3): Enhanced Data Visualization

In this article, we will perform Enhanced Data Visualization by going beyond basic charts by incorporating features like interactivity, layered data, and dynamic elements, enabling traders to explore trends, patterns, and correlations more effectively.
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From Basic to Intermediate: Array (IV)

From Basic to Intermediate: Array (IV)

In this article, we'll look at how you can do something very similar to what's implemented in languages like C, C++, and Java. I am talking about passing a virtually infinite number of parameters inside a function or procedure. While this may seem like a fairly advanced topic, in my opinion, what will be shown here can be easily implemented by anyone who has understood the previous concepts. Provided that they were really properly understood.
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Neural Networks in Trading: Hierarchical Dual-Tower Transformer (Hidformer)

Neural Networks in Trading: Hierarchical Dual-Tower Transformer (Hidformer)

We invite you to get acquainted with the Hierarchical Double-Tower Transformer (Hidformer) framework, which was developed for time series forecasting and data analysis. The framework authors proposed several improvements to the Transformer architecture, which resulted in increased forecast accuracy and reduced computational resource consumption.
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Spurious Regressions in Python

Spurious Regressions in Python

Spurious regressions occur when two time series exhibit a high degree of correlation purely by chance, leading to misleading results in regression analysis. In such cases, even though variables may appear to be related, the correlation is coincidental and the model may be unreliable.
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Biological neuron for forecasting financial time series

Biological neuron for forecasting financial time series

We will build a biologically correct system of neurons for time series forecasting. The introduction of a plasma-like environment into the neural network architecture creates a kind of "collective intelligence," where each neuron influences the system's operation not only through direct connections, but also through long-range electromagnetic interactions. Let's see how the neural brain modeling system will perform in the market.
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Developing a Replay System (Part 67): Refining the Control Indicator

Developing a Replay System (Part 67): Refining the Control Indicator

In this article, we'll look at what can be achieved with a little code refinement. This refinement is aimed at simplifying our code, making more use of MQL5 library calls and, above all, making it much more stable, secure and easy to use in other projects that we may develop in the future.
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Feature Engineering With Python And MQL5 (Part III): Angle Of Price (2) Polar Coordinates

Feature Engineering With Python And MQL5 (Part III): Angle Of Price (2) Polar Coordinates

In this article, we take our second attempt to convert the changes in price levels on any market, into a corresponding change in angle. This time around, we selected a more mathematically sophisticated approach than we selected in our first attempt, and the results we obtained suggest that our change in approach may have been the right decision. Join us today, as we discuss how we can use Polar coordinates to calculate the angle formed by changes in price levels, in a meaningful way, regardless of which market you are analyzing.
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Reimagining Classic Strategies (Part 14): High Probability Setups

Reimagining Classic Strategies (Part 14): High Probability Setups

High probability Setups are well known in our trading community, but regrettably they are not well-defined. In this article, we will aim to find an empirical and algorithmic way of defining exactly what is a high probability setup, identifying and exploiting them. By using Gradient Boosting Trees, we demonstrated how the reader can improve the performance of an arbitrary trading strategy and better communicate the exact job to be done to our computer in a more meaningful and explicit manner.
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MQL5 Trading Tools (Part 14): Pixel-Perfect Scrollable Text Canvas with Antialiasing and Rounded Scrollbar

MQL5 Trading Tools (Part 14): Pixel-Perfect Scrollable Text Canvas with Antialiasing and Rounded Scrollbar

In this article, we enhance the canvas-based price dashboard in MQL5 by adding a pixel-perfect scrollable text panel for usage guides, overcoming native scrolling limitations through custom antialiasing and a rounded scrollbar design with hover-expand functionality. The text panel supports themed backgrounds with opacity, dynamic line wrapping for content like instructions and contacts, and interactive navigation via up/down buttons, slider dragging, and mouse wheel scrolling within the body area.
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Anarchic Society Optimization (ASO) algorithm

Anarchic Society Optimization (ASO) algorithm

In this article, we will get acquainted with the Anarchic Society Optimization (ASO) algorithm and discuss how an algorithm based on the irrational and adventurous behavior of participants in an anarchic society (an anomalous system of social interaction free from centralized power and various kinds of hierarchies) is able to explore the solution space and avoid the traps of local optimum. The article presents a unified ASO structure applicable to both continuous and discrete problems.
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Requesting in Connexus (Part 6): Creating an HTTP Request and Response

Requesting in Connexus (Part 6): Creating an HTTP Request and Response

In this sixth article of the Connexus library series, we will focus on a complete HTTP request, covering each component that makes up a request. We will create a class that represents the request as a whole, which will help us bring together the previously created classes.
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Implementing Practical Modules from Other Languages in MQL5 (Part 04): time, date, and datetime modules from Python

Implementing Practical Modules from Other Languages in MQL5 (Part 04): time, date, and datetime modules from Python

Unlike MQL5, Python programming language offers control and flexibility when it comes to dealing with and manipulating time. In this article, we will implement similar modules for better handling of dates and time in MQL5 as in Python.
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Building an EquiVolume Indicator in MQL5

Building an EquiVolume Indicator in MQL5

We implement an EquiVolume indicator in MQL5 that converts standard candlesticks into volume-weighted boxes. The workflow includes selecting volume type, detecting the maximum volume within a lookback range, normalizing all values against it, and mapping them into proportional box widths. The result is a chart-based structure that visualizes trading activity intensity alongside price movement in MetaTrader 5.
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Causal inference in time series classification problems

Causal inference in time series classification problems

In this article, we will look at the theory of causal inference using machine learning, as well as the custom approach implementation in Python. Causal inference and causal thinking have their roots in philosophy and psychology and play an important role in our understanding of reality.
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From Basic to Intermediate: Arrays and Strings (II)

From Basic to Intermediate: Arrays and Strings (II)

In this article I will show that although we are still at a very basic stage of programming, we can already implement some interesting applications. In this case, we will create a fairly simple password generator. This way we will be able to apply some of the concepts that have been explained so far. In addition, we will look at how solutions can be developed for some specific problems.
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Integrating Computer Vision into Trading in MQL5 (Part 2): Extending the Architecture to 2D RGB Image Analysis

Integrating Computer Vision into Trading in MQL5 (Part 2): Extending the Architecture to 2D RGB Image Analysis

Computer vision for trading: how it works and how to develop it step by step. We create an algorithm for recognition of RGB images of price charts using the attention mechanism and a bidirectional LSTM layer. As a result, we obtain a working model for forecasting the EURUSD price with the accuracy of up to 55% in the validation section.
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Neural Networks Made Easy (Part 90): Frequency Interpolation of Time Series (FITS)

Neural Networks Made Easy (Part 90): Frequency Interpolation of Time Series (FITS)

By studying the FEDformer method, we opened the door to the frequency domain of time series representation. In this new article, we will continue the topic we started. We will consider a method with which we can not only conduct an analysis, but also predict subsequent states in a particular area.
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Neural networks are easy (Part 59): Dichotomy of Control (DoC)

Neural networks are easy (Part 59): Dichotomy of Control (DoC)

In the previous article, we got acquainted with the Decision Transformer. But the complex stochastic environment of the foreign exchange market did not allow us to fully implement the potential of the presented method. In this article, I will introduce an algorithm that is aimed at improving the performance of algorithms in stochastic environments.
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Neural Networks in Trading: Generalized 3D Referring Expression Segmentation

Neural Networks in Trading: Generalized 3D Referring Expression Segmentation

While analyzing the market situation, we divide it into separate segments, identifying key trends. However, traditional analysis methods often focus on one aspect and thus limit the proper perception. In this article, we will learn about a method that enables the selection of multiple objects to ensure a more comprehensive and multi-layered understanding of the situation.
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From Basic to Intermediate: Template and Typename (III)

From Basic to Intermediate: Template and Typename (III)

In this article, we will discuss the first part of the topic, which is not so easy for beginners to understand. In order not to get even more confused and to explain this topic correctly, we will divide the explanation into stages. We will devote this article to the first stage. However, although at the end of the article it may seem that we have reached the deadlock, in fact we will take a step towards another situation, which will be better understood in the next article.
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Category Theory in MQL5 (Part 17): Functors and Monoids

Category Theory in MQL5 (Part 17): Functors and Monoids

This article, the final in our series to tackle functors as a subject, revisits monoids as a category. Monoids which we have already introduced in these series are used here to aid in position sizing, together with multi-layer perceptrons.
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Introduction to MQL5 (Part 32): Mastering API and WebRequest Function in MQL5 (VI)

Introduction to MQL5 (Part 32): Mastering API and WebRequest Function in MQL5 (VI)

This article will show you how to visualize candle data obtained via the WebRequest function and API in candle format. We'll use MQL5 to read the candle data from a CSV file and display it as custom candles on the chart, since indicators cannot directly use the WebRequest function.
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Most notable Artificial Cooperative Search algorithm modifications (ACSm)

Most notable Artificial Cooperative Search algorithm modifications (ACSm)

Here we will consider the evolution of the ACS algorithm: three modifications aimed at improving the convergence characteristics and the algorithm efficiency. Transformation of one of the leading optimization algorithms. From matrix modifications to revolutionary approaches regarding population formation.