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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Market Simulation (Part 12): Sockets (VI)

Market Simulation (Part 12): Sockets (VI)

In this article, we will look at how to solve certain problems and issues that arise when using Python code within other programs. More specifically, we will demonstrate a common issue encountered when using Excel in conjunction with MetaTrader 5, although we will be using Python to facilitate this interaction. However, this implementation has a minor drawback. It does not occur in all cases, but only in certain specific situations. When it does happen, it is necessary to understand the cause. In today’s article, we will begin explaining how to resolve this issue.
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Adaptive Social Behavior Optimization (ASBO): Two-phase evolution

Adaptive Social Behavior Optimization (ASBO): Two-phase evolution

We continue dwelling on the topic of social behavior of living organisms and its impact on the development of a new mathematical model - ASBO (Adaptive Social Behavior Optimization). We will dive into the two-phase evolution, test the algorithm and draw conclusions. Just as in nature a group of living organisms join their efforts to survive, ASBO uses principles of collective behavior to solve complex optimization problems.
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Bivariate Copulae in MQL5 (Part 3): Implementation and Tuning of Mixed Copula Models in MQL5

Bivariate Copulae in MQL5 (Part 3): Implementation and Tuning of Mixed Copula Models in MQL5

The article extends our copula toolkit with mixed copulas implemented natively in MQL5. We construct Clayton–Frank–Gumbel and Clayton–Student–t–Gumbel mixtures, estimate them via EM, and enable sparsity control through SCAD with cross‑validation. Provided scripts tune hyperparameters, compare mixtures using information criteria, and save trained models. Practitioners can apply these components to capture asymmetric tail dependence and embed the selected model in indicators or Expert Advisors.
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Feature selection and dimensionality reduction using principal components

Feature selection and dimensionality reduction using principal components

The article delves into the implementation of a modified Forward Selection Component Analysis algorithm, drawing inspiration from the research presented in “Forward Selection Component Analysis: Algorithms and Applications” by Luca Puggini and Sean McLoone.
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Neural Networks in Trading: Actor—Director—Critic

Neural Networks in Trading: Actor—Director—Critic

We invite you to explore the Actor-Director-Critic framework, which combines hierarchical learning and a multi-component architecture for creating adaptive trading strategies. In this article, we take a detailed look at how using the Director to classify the Actor's actions helps to effectively optimize trading decisions and improve the robustness of models in financial market conditions.
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Developing a Replay System (Part 35): Making Adjustments (I)

Developing a Replay System (Part 35): Making Adjustments (I)

Before we can move forward, we need to fix a few things. These are not actually the necessary fixes but rather improvements to the way the class is managed and used. The reason is that failures occurred due to some interaction within the system. Despite attempts to find out the cause of such failures in order to eliminate them, all these attempts were unsuccessful. Some of these cases make no sense, for example, when we use pointers or recursion in C/C++, the program crashes.
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The case for using Hospital-Performance Data with Perceptrons, this Q4, in weighing SPDR XLV's next Performance

The case for using Hospital-Performance Data with Perceptrons, this Q4, in weighing SPDR XLV's next Performance

XLV is SPDR healthcare ETF and in an age where it is common to be bombarded by a wide array of traditional news items plus social media feeds, it can be pressing to select a data set for use with a model. We try to tackle this problem for this ETF by sizing up some of its critical data sets in MQL5.
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From Novice to Expert: Animated News Headline Using MQL5 (V)—Event Reminder System

From Novice to Expert: Animated News Headline Using MQL5 (V)—Event Reminder System

In this discussion, we’ll explore additional advancements as we integrate refined event‑alerting logic for the economic calendar events displayed by the News Headline EA. This enhancement is critical—it ensures users receive timely notifications a short time before key upcoming events. Join this discussion to discover more.
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Market Positioning Codex for VGT with Kendall's Tau and Distance Correlation

Market Positioning Codex for VGT with Kendall's Tau and Distance Correlation

In this article, we look to explore how a complimentary indicator pairing can be used to analyze the recent 5-year history of Vanguard Information Technology Index Fund ETF. By considering two options of algorithms, Kendall’s Tau and Distance-Correlation, we look to select not just an ideal indicator pair for trading the VGT, but also suitable signal-pattern pairings of these two indicators.
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MQL5 Trading Tools (Part 27): Rendering Parametric Butterfly Curve on Canvas

MQL5 Trading Tools (Part 27): Rendering Parametric Butterfly Curve on Canvas

In this article, we explore the butterfly curve, a parametric mathematical equation, and render it visually on a MQL5 canvas. We build an interactive display with a draggable, resizable canvas window, supersampled curve rendering, gradient backgrounds, and a color-segmented legend. By the end, we have a fully functional visual tool that plots the butterfly curve directly on the MetaTrader 5 chart.
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Developing a Replay System (Part 55): Control Module

Developing a Replay System (Part 55): Control Module

In this article, we will implement a control indicator so that it can be integrated into the message system we are developing. Although it is not very difficult, there are some details that need to be understood about the initialization of this module. The material presented here is for educational purposes only. In no way should it be considered as an application for any purpose other than learning and mastering the concepts shown.
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MQL5 Trading Tools (Part 27): Rendering Parametric Butterfly Curve on Canvas

MQL5 Trading Tools (Part 27): Rendering Parametric Butterfly Curve on Canvas

In this article, we explore the butterfly curve, a parametric mathematical equation, and render it visually on a MQL5 canvas. We build an interactive display with a draggable, resizable canvas window, supersampled curve rendering, gradient backgrounds, and a color-segmented legend. By the end, we have a fully functional visual tool that plots the butterfly curve directly on the MetaTrader 5 chart.
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Markets Positioning Codex in MQL5 (Part 2):  Bitwise Learning, with Multi-Patterns for Nvidia

Markets Positioning Codex in MQL5 (Part 2): Bitwise Learning, with Multi-Patterns for Nvidia

We continue our new series on Market-Positioning, where we study particular assets, with specific trade directions over manageable test windows. We started this by considering Nvidia Corp stock in the last article, where we covered 5 signal patterns from the complimentary pairing of the RSI and DeMarker oscillators. For this article, we cover the remaining 5 patterns and also delve into multi-pattern options that not only feature untethered combinations of all ten, but also specialized combinations of just a pair.
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Engineering a Self-Healing Expert Advisor in MQL5 (Part 1): Persistent Trade State Architecture

Engineering a Self-Healing Expert Advisor in MQL5 (Part 1): Persistent Trade State Architecture

This article demonstrates how to build the persistence foundation of a self-healing Expert Advisor in MQL5 using SQLite. Readers will learn how to create a permanent trade-state storage layer capable of surviving terminal restarts, shutdowns, and unexpected interruptions. The article covers SQLite integration in MetaTrader 5, database lifecycle management, persistent trade-state structures, and runtime state recovery using practical MQL5 implementations.
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File-Based Versioning of EA Parameters in MQL5

File-Based Versioning of EA Parameters in MQL5

This article explains how to implement parameter versioning in MQL5 using binary files and packed structures. It shows how to write and read fixed-size records with FileWriteStruct and FileReadStruct in FILE_BIN mode, including version numbers, timestamps, and a checksum. You will also see how to detect changes via checksums, append records safely, and load the latest configuration without overwriting prior settings.
All about Automated Trading Championship: Reporting the Championship 2007
All about Automated Trading Championship: Reporting the Championship 2007

All about Automated Trading Championship: Reporting the Championship 2007

The present article contains Weekly Reports of the ATC 2007. These materials are like snapshots, they are interesting-to-read not only during the Championship, but years later as well.
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File-Based Versioning of EA Parameters in MQL5

File-Based Versioning of EA Parameters in MQL5

This article explains how to implement parameter versioning in MQL5 using binary files and packed structures. It shows how to write and read fixed-size records with FileWriteStruct and FileReadStruct in FILE_BIN mode, including version numbers, timestamps, and a checksum. You will also see how to detect changes via checksums, append records safely, and load the latest configuration without overwriting prior settings.
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Mastering Log Records (Part 2): Formatting Logs

Mastering Log Records (Part 2): Formatting Logs

In this article, we will explore how to create and apply log formatters in the library. We will see everything from the basic structure of a formatter to practical implementation examples. By the end, you will have the necessary knowledge to format logs within the library, and understand how everything works behind the scenes.
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Building a Trade Analytics System (Part 2): How to Capture Closed Trades and Send JSON in MQL5

Building a Trade Analytics System (Part 2): How to Capture Closed Trades and Send JSON in MQL5

We build a lightweight bridge that captures closed trades in MetaTrader 5 and sends them to an external backend over HTTP as JSON. It uses OnTradeTransaction for event detection, reads details from deal history, assembles a JSON payload, and posts it via WebRequest. A local Flask API is used to test the flow, delivering a working path to move trade data outside the terminal.
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From Basic to Intermediate: Objects (II)

From Basic to Intermediate: Objects (II)

In today's article, we will look at how to control some object properties in a simple way using code. We will also see how a custom application can place more than one object on the same chart. In addition, we will begin to understand the importance of assigning a short name to any indicator we plan to implement.
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Data Science and ML (Part 48): Are Transformers a Big Deal for Trading?

Data Science and ML (Part 48): Are Transformers a Big Deal for Trading?

From ChatGPT to Gemini and many model AI tools for text, image, and video generation. Transformers have rocked the AI-world. But, are they applicable in the financial (trading) space? Let's find out.
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Graph Theory: Traversal Breadth-First Search (BFS) Applied in Trading

Graph Theory: Traversal Breadth-First Search (BFS) Applied in Trading

Breadth First Search (BFS) uses level-order traversal to model market structure as a directed graph of price swings evolving through time. By analyzing historical bars or sessions layer by layer, BFS prioritizes recent price behavior while still respecting deeper market memory.
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Reimagining Classic Strategies (Part VII) : Forex Markets And Sovereign Debt Analysis on the USDJPY

Reimagining Classic Strategies (Part VII) : Forex Markets And Sovereign Debt Analysis on the USDJPY

In today's article, we will analyze the relationship between future exchange rates and government bonds. Bonds are among the most popular forms of fixed income securities and will be the focus of our discussion.Join us as we explore whether we can improve a classic strategy using AI.
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Data Science and ML (Part 48): Are Transformers a Big Deal for Trading?

Data Science and ML (Part 48): Are Transformers a Big Deal for Trading?

From ChatGPT to Gemini and many model AI tools for text, image, and video generation. Transformers have rocked the AI-world. But, are they applicable in the financial (trading) space? Let's find out.
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Implementing Practical Modules from Other Languages in MQL5 (Part 05): The Logging module from Python, Log Like a Pro

Implementing Practical Modules from Other Languages in MQL5 (Part 05): The Logging module from Python, Log Like a Pro

Integrating Python's logging module with MQL5 empowers traders with a systematic logging approach, simplifying the process of monitoring, debugging, and documenting trading activities. This article explains the adaptation process, offering traders a powerful tool for maintaining clarity and organization in trading software development.
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Stepwise feature selection in MQL5

Stepwise feature selection in MQL5

In this article, we introduce a modified version of stepwise feature selection, implemented in MQL5. This approach is based on the techniques outlined in Modern Data Mining Algorithms in C++ and CUDA C by Timothy Masters.
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Developing an MQTT client for Metatrader 5: a TDD approach — Part 5

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

This article is the fifth part of a series describing our development steps of a native MQL5 client for the MQTT 5.0 protocol. In this part we describe the structure of PUBLISH packets, how we are setting their Publish Flags, encoding Topic Name(s) strings, and setting Packet Identifier(s) when required.
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Introduction to MQL5 (Part 39): Beginner Guide to File Handling in MQL5 (I)

Introduction to MQL5 (Part 39): Beginner Guide to File Handling in MQL5 (I)

This article introduces file handling in MQL5 using a practical, project-based workflow. You will use FileSelectDialog to choose or create a CSV file, open it with FileOpen, and write structured account headers such as account name, balance, login, date range, and last update. The result is a clear foundation for a reusable trading journal and safe file operations in MetaTrader 5.
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From Basic to Intermediate: Union (I)

From Basic to Intermediate: Union (I)

In this article we will look at what a union is. Here, through experiments, we will analyze the first constructions in which union can be used. However, what will be shown here is only a core part of a set of concepts and information that will be covered in subsequent articles. 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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Biogeography-Based Optimization (BBO)

Biogeography-Based Optimization (BBO)

Biogeography-Based Optimization (BBO) is an elegant global optimization method inspired by natural processes of species migration between islands within archipelagos. The algorithm is based on a simple yet powerful idea: high-quality solutions actively share their characteristics, while low-quality ones actively adopt new features, creating a natural flow of information from the best solutions to the worst. A unique adaptive mutation operator provides an excellent balance between exploration and exploitation. BBO demonstrates high efficiency on a variety of tasks.
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Building Volatility Models in MQL5 (Part III): Implementing the SLSQP Algorithm for Model Estimation

Building Volatility Models in MQL5 (Part III): Implementing the SLSQP Algorithm for Model Estimation

An SLSQP optimizer is implemented in MQL5 to resolve parameter discrepancies between a volatility library and Python's ARCH module. The article details constraint handling, gradient options, configuration, and convergence controls and shows how to integrate the solver into existing code. Practical examples and comparisons demonstrate matched log‑likelihoods and parameters on shared datasets.
All about Automated Trading Championship: Reporting the Championship 2006
All about Automated Trading Championship: Reporting the Championship 2006

All about Automated Trading Championship: Reporting the Championship 2006

This article contains Weekly Reports of the ATC 2006. These materials are like snapshots, they are interesting-to-read not only during the Championship, but years later as well.
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Developing a Replay System (Part 39): Paving the Path (III)

Developing a Replay System (Part 39): Paving the Path (III)

Before we proceed to the second stage of development, we need to revise some ideas. Do you know how to make MQL5 do what you need? Have you ever tried to go beyond what is contained in the documentation? If not, then get ready. Because we will be doing something that most people don't normally do.
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Building Volatility Models in MQL5 (Part III): Implementing the SLSQP Algorithm for Model Estimation

Building Volatility Models in MQL5 (Part III): Implementing the SLSQP Algorithm for Model Estimation

An SLSQP optimizer is implemented in MQL5 to resolve parameter discrepancies between a volatility library and Python's ARCH module. The article details constraint handling, gradient options, configuration, and convergence controls and shows how to integrate the solver into existing code. Practical examples and comparisons demonstrate matched log‑likelihoods and parameters on shared datasets.
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Evaluating the Quality of Forex Spread Trading Based on Seasonal Factors in MetaTrader 5

Evaluating the Quality of Forex Spread Trading Based on Seasonal Factors in MetaTrader 5

The article examines the quality of a seasonal trading approach on a daily timeframe, both for individual symbols and for spreads. Particular attention is paid to identifying recurring monthly cycles and the possibilities of their application in trading within the current year.
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Developing a Replay System (Part 41): Starting the second phase (II)

Developing a Replay System (Part 41): Starting the second phase (II)

If everything seemed right to you up to this point, it means you're not really thinking about the long term, when you start developing applications. Over time you will no longer need to program new applications, you will just have to make them work together. So let's see how to finish assembling the mouse indicator.
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Developing a Replay System (Part 34): Order System (III)

Developing a Replay System (Part 34): Order System (III)

In this article, we will complete the first phase of construction. Although this part is fairly quick to complete, I will cover details that were not discussed previously. I will explain some points that many do not understand. Do you know why you have to press the Shift or Ctrl key?
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Implementing a Breakeven Mechanism in MQL5 (Part 2): ATR- and RRR-Based Breakeven

Implementing a Breakeven Mechanism in MQL5 (Part 2): ATR- and RRR-Based Breakeven

This article completes the implementation of ATR- and RRRR-based breakeven mechanisms in MQL5 and develops, from scratch, a class that makes it easy to switch breakeven modes without having to enter the parameters again. To evaluate the effectiveness of each breakeven type, several backtests are run, analyzing their advantages and disadvantages in the context of algorithmic trading.
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From Basic to Intermediate: Events (II)

From Basic to Intermediate: Events (II)

In this article, we will see that not everything always needs to be implemented in a certain specific way. There are alternative approaches to problem-solving. To properly understand this article, it is necessary to grasp the concepts described in the previous articles. The materials presented here are for educational purposes only. Do not regard it as a finished application. Its purpose is to study the concepts presented here.
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Header in the Connexus (Part 3): Mastering the Use of HTTP Headers for Requests

Header in the Connexus (Part 3): Mastering the Use of HTTP Headers for Requests

We continue developing the Connexus library. In this chapter, we explore the concept of headers in the HTTP protocol, explaining what they are, what they are for, and how to use them in requests. We cover the main headers used in communications with APIs, and show practical examples of how to configure them in the library.