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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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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Developing a Replay System (Part 64): Playing the service (V)

Developing a Replay System (Part 64): Playing the service (V)

In this article, we will look at how to fix two errors in the code. However, I will try to explain them in a way that will help you, beginner programmers, understand that things don't always go as you expect. Anyway, this is an opportunity to learn. The content presented here is intended solely for educational purposes. In no way should this application be considered as a final document with any purpose other than to explore the concepts presented.
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How to Train an MLP Using Markov Chain Features in MQL5

How to Train an MLP Using Markov Chain Features in MQL5

The article describes the two-level MarkovMLPOscillator indicator: a three-state Markov chain uses historical data to construct a transition matrix and generate 15 probabilistic features for each bar, and an MLP is trained on these features to predict price direction at a specified forecast horizon. The article covers feature generation, the validation procedure using a holdout set, and parameter settings. The result is an interpretable oscillator with a color histogram, a smoothed signal, and a display of the current transition matrix.
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Neural Networks in Trading: Actor—Director—Critic (Final Part)

Neural Networks in Trading: Actor—Director—Critic (Final Part)

The Actor–Director–Critic framework is an evolution of the classic agent learning architecture. The article presents practical experience of its implementation and adaptation to financial market conditions.
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MQL5 Wizard Techniques you should know (Part 88): Using Blooms Filter with a Custom Trailing Class

MQL5 Wizard Techniques you should know (Part 88): Using Blooms Filter with a Custom Trailing Class

Our next focus in these series on ideas that can be rapidly prototyped with the MQL5 Wizard, is a Custom Trailing class that uses the Blooming Filter. Trailing Stop systems are an optional but very resourceful part to any trading system that we want to explore more in these series besides the traditional Entry Signals.
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MetaTrader 5 Machine Learning Blueprint (Part 20): Denoising, Detoning, and Clustering the Feature Correlation Matrix

MetaTrader 5 Machine Learning Blueprint (Part 20): Denoising, Detoning, and Clustering the Feature Correlation Matrix

Raw feature correlations contain estimation noise and a shared market-mode component that distort clustering. We fit the Marcenko–Pastur noise ceiling (with an effective sample size correction), apply constant-residual denoising and market detonation, and run the Optimal Number of Clusters routine. The result is a cleaned correlation matrix and stable cluster labels that avoid substitution effects and feed clustered MDI/MDA in the next article.
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Community of Scientists Optimization (CoSO): Theory

Community of Scientists Optimization (CoSO): Theory

Secrets of effective optimization of trading strategies in metaheuristic approaches. Community of Scientists Optimization is a new population-based algorithm inspired by the mechanisms of the scientific community. Unlike traditional nature-inspired metaphors, CoSO models unique aspects of human scientific activity: publishing results in journals, competing for grants, and forming research teams.
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Table and Header Classes based on a table model in MQL5: Applying the MVC concept

Table and Header Classes based on a table model in MQL5: Applying the MVC concept

This is the second part of the article devoted to the implementation of the table model in MQL5 using the MVC (Model-View-Controller) architectural paradigm. The article discusses the development of table classes and the table header based on a previously created table model. The developed classes will form the basis for further implementation of View and Controller components, which will be discussed in the following articles.
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Mastering Log Records (Part 9): Implementing the builder pattern and adding default configurations

Mastering Log Records (Part 9): Implementing the builder pattern and adding default configurations

This article shows how to drastically simplify the use of the Logify library with the Builder pattern and automatic default configurations. It explains the structure of the specialized builders, how to use them with smart auto-completion, and how to ensure a functional log even without manual configuration. It also covers tweaks for MetaTrader 5 build 5100.
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Developing a Replay System (Part 30): Expert Advisor project — C_Mouse class (IV)

Developing a Replay System (Part 30): Expert Advisor project — C_Mouse class (IV)

Today we will learn a technique that can help us a lot in different stages of our professional life as a programmer. Often it is not the platform itself that is limited, but the knowledge of the person who talks about the limitations. This article will tell you that with common sense and creativity you can make the MetaTrader 5 platform much more interesting and versatile without resorting to creating crazy programs or anything like that, and create simple yet safe and reliable code. We will use our creativity to modify existing code without deleting or adding a single line to the source code.
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Creating an HTML Dashboard for Strategy Tester and Prop Firm Challenge Analysis in MQL5

Creating an HTML Dashboard for Strategy Tester and Prop Firm Challenge Analysis in MQL5

This article demonstrates how to build a reusable prop‑firm evaluation module for MQL5 Expert Advisors and export results to an HTML dashboard. The module monitors balance and equity during backtests, simulates single or rolling challenges, checks profit target, daily and overall drawdown, and minimum trading days, then outputs both a terminal summary and a browser‑readable report.
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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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MQL5 Trading Tools (Part 37): Adding a Per-Object Property-Editing Ribbon to the Canvas Drawing Layer

MQL5 Trading Tools (Part 37): Adding a Per-Object Property-Editing Ribbon to the Canvas Drawing Layer

We add a descriptor-driven property stack and a floating ribbon that binds to the current selection on the drawing layer. The article covers the descriptor list for each tool, the engine get/set API with snapshot-and-restore live preview, and widget renderers for color, opacity, line width, line style, fonts, and level visibility. You get in-place, real-time editing of object appearance via a compact, draggable panel.
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Building an Object-Oriented Session VWAP Engine in MQL5

Building an Object-Oriented Session VWAP Engine in MQL5

This article shows how to implement a session vwap in MQL5 as a reusable include class with a strict daily reset at broker midnight. The engine computes VWAP and volume‑weighted deviation bands only on closed bars and anchors accumulation with MqlDateTime to avoid distortions from missing candles. A companion indicator plots the baseline and bands, while an Expert Advisor reads signals once per bar for consistent, CPU‑efficient execution and reliable testing.
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Execution Cost and Slippage Sensitivity Analyzer

Execution Cost and Slippage Sensitivity Analyzer

Backtests often understate spread, commission, and slippage. This MQL5 analyzer loads closing deals and simulates rising execution costs to measure robustness. It computes the breakeven cost per deal, the cushion over an assumed cost, the net profit and profit factor at that cost, and how many winners turn into losers, then summarizes the result with an A+ to F grade and targeted guidance.
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Reimagining Classic Strategies (Part VIII): Currency Markets And Precious Metals on the USDCAD

Reimagining Classic Strategies (Part VIII): Currency Markets And Precious Metals on the USDCAD

In this series of articles, we revisit well-known trading strategies to see if we can improve them using AI. In today's discussion, join us as we test whether there is a reliable relationship between precious metals and currencies.
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Mastering Log Records (Part 10): Avoiding Log Replay by Implementing a Suppression

Mastering Log Records (Part 10): Avoiding Log Replay by Implementing a Suppression

We created a log suppression system in the Logify library. It details how the CLogifySuppression class reduces console noise by applying configurable rules to avoid repetitive or irrelevant messages. We also cover the external configuration framework, validation mechanisms, and comprehensive testing to ensure robustness and flexibility in log capture during bot or indicator development.
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Bayesian Online Change-Point Detection (BOCPD) in MQL5: One Regime-Break Signal, Three Ways to Use It

Bayesian Online Change-Point Detection (BOCPD) in MQL5: One Regime-Break Signal, Three Ways to Use It

This article delivers Bayesian Online Change-Point Detection as a single, dependency-free MQL5 class that maintains a per-bar, causal probability of a regime break. We use it three ways: a live monitor, a moving average that flushes on breaks, and a risk overlay with a matched-frequency random control. Readers get a reusable primitive to watch structural change, adapt indicators, and gate exposure after detected shifts.
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Forecasting a Conditional Distribution Using MLP

Forecasting a Conditional Distribution Using MLP

In this article, we will consider an MLP-based regression model that predicts not only the conditional expectation but also the conditional variance. In other words, we will train our network to predict the entire distribution of future prices based on the input feature vector. But for this purpose we will have to implement our own loss function.
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Building a Future Swing Projection Indicator in MQL5

Building a Future Swing Projection Indicator in MQL5

We implement a Future Swing Projection indicator in MQL5 that analyzes historical swing structure and estimates the next move from recent price behavior. It locates six alternating swing points, measures five completed legs, and uses their average distance to project a target five bars ahead. The indicator draws swing legs, a projection line, ATR‑based support and resistance zones, and a label with the projected price to keep the process rule‑based and reproducible.
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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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Engineering a Self-Healing Expert Advisor in MQL5 (Part 5): Real-Time Recovery Dashboard (Final Part)

Engineering a Self-Healing Expert Advisor in MQL5 (Part 5): Real-Time Recovery Dashboard (Final Part)

This article implements a real-time monitoring dashboard for a self-healing MetaTrader 5 Expert Advisor. The dashboard displays the current EA state, virtual stop-loss and take-profit levels, breakeven and trailing status, recovery state, synchronization status, and heartbeat information directly on the chart. By exposing the internal recovery state visually, the Expert Advisor becomes easier to monitor, verify, and troubleshoot while managing active trades.
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Developing a Terminal Manager (Part 3): Getting Account Information and Adding Configuration

Developing a Terminal Manager (Part 3): Getting Account Information and Adding Configuration

We are adding to our web application the ability to retrieve and display information about the terminal instances’ trading accounts, including balance, profit, connection status, and other important details. We will also implement a flexible configuration system that lets you manage application settings via an external JSON file, and improve the user interface of the main page.
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MQL5 Trading Tools (Part 38): Adding a Tabbed Settings Window for Editing Object Properties

MQL5 Trading Tools (Part 38): Adding a Tabbed Settings Window for Editing Object Properties

We add a tabbed settings window opened from the ribbon and bound to the selected object. The tabs — Style, Text, Coordinates, and Visibility — are built from the same descriptor system, with scrolling, per-level rows, and shared color/width/style popovers. The article covers layout, rendering, interaction, and inline price/time and numeric editing. You get one place to edit every property with live preview and commit-or-discard on close.
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Neural Networks in Trading: A Spiking-Semantic Approach to Spatiotemporal Identification (Key Components)

Neural Networks in Trading: A Spiking-Semantic Approach to Spatiotemporal Identification (Key Components)

In this article, we took a detailed look at the integration of the SSAM module into the SEW-ResNeXt block, demonstrating how the S3CE-Net framework enables the effective combination of spiking attention with residual blocks. This architecture ensures accurate processing of temporal and spatial data streams and high training stability. The modularity and flexibility of the components make it easier to extend the model and reuse proven methods.
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Market Simulation: Position View (V)

Market Simulation: Position View (V)

Despite what was shown in the previous article, all of this may seem simple at first. In reality, several problems remain, along with many tasks that still need to be completed. You, dear reader, may imagine that everything is easy and straightforward. Out of inexperience, you may simply accept whatever is presented to you. And that is a mistake you should try to avoid. Even worse is trying to use something without truly understanding what exactly you are using. Beginners often pass through a copy-and-paste stage. If you do not want to remain stuck at that stage forever, you should learn how to use certain tools. One of the tools most often used by programmers is documentation. The second is testing, supported by log files. Here we will see how to do this.
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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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MQL5 Wizard Techniques you should know (Part 23): CNNs

MQL5 Wizard Techniques you should know (Part 23): CNNs

Convolutional Neural Networks are another machine learning algorithm that tend to specialize in decomposing multi-dimensioned data sets into key constituent parts. We look at how this is typically achieved and explore a possible application for traders in another MQL5 wizard signal class.
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Neural networks made easy (Part 77): Cross-Covariance Transformer (XCiT)

Neural networks made easy (Part 77): Cross-Covariance Transformer (XCiT)

In our models, we often use various attention algorithms. And, probably, most often we use Transformers. Their main disadvantage is the resource requirement. In this article, we will consider a new algorithm that can help reduce computing costs without losing quality.
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Training Neural Networks on Oscillators Without Look-Ahead Bias

Training Neural Networks on Oscillators Without Look-Ahead Bias

The article describes an approach to trade labeling using oscillators for machine learning models. This eliminates look-ahead bias. It has been shown that this type of labeling does not lead to model overfitting, and the strategies continue to perform well over the long term.
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Neural networks made easy (Part 70): Closed-Form Policy Improvement Operators (CFPI)

Neural networks made easy (Part 70): Closed-Form Policy Improvement Operators (CFPI)

In this article, we will get acquainted with an algorithm that uses closed-form policy improvement operators to optimize Agent actions in offline mode.
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Atmosphere Clouds Model Optimization (ACMO): Theory

Atmosphere Clouds Model Optimization (ACMO): Theory

The article is devoted to the metaheuristic Atmosphere Clouds Model Optimization (ACMO) algorithm, which simulates the behavior of clouds to solve optimization problems. The algorithm uses the principles of cloud generation, movement and propagation, adapting to the "weather conditions" in the solution space. The article reveals how the algorithm's meteorological simulation finds optimal solutions in a complex possibility space and describes in detail the stages of ACMO operation, including "sky" preparation, cloud birth, cloud movement, and rain concentration.
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Symbolic Price Forecasting Equation Using SymPy

Symbolic Price Forecasting Equation Using SymPy

The article describes an interesting approach to algorithmic trading based on symbolic mathematical equations instead of traditional machine learning "black boxes". The author demonstrates how to transform opaque neural networks into readable mathematical equations using the SymPy library and polynomial regression, allowing for a full understanding of the logic behind trading decisions. The approach combines the computational power of ML with the transparency of classical methods, giving traders the ability to analyze, adjust, and adapt models in real time.
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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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Client in Connexus (Part 7): Adding the Client Layer

Client in Connexus (Part 7): Adding the Client Layer

In this article we continue the development of the connexus library. In this chapter we build the CHttpClient class responsible for sending a request and receiving an order. We also cover the concept of mocks, leaving the library decoupled from the WebRequest function, which allows greater flexibility for users.
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Developing a Multi-Currency Expert Advisor (Part 28): Adding a Position Closing Manager

Developing a Multi-Currency Expert Advisor (Part 28): Adding a Position Closing Manager

When running multiple strategies in parallel, you may want to periodically close all open positions and start the strategies over again. The existing code only allows this behavior to be implemented through manual intervention. Let's try to automate this part.
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Market Microstructure in MQL5 (Part 2): Measuring long memory in MQL5 with Hurst estimators

Market Microstructure in MQL5 (Part 2): Measuring long memory in MQL5 with Hurst estimators

Part 2 focuses on practical long-memory detection for intraday data. Three complementary Hurst estimators are implemented and combined into a confidence‑weighted composite, with confidence tied to valid regression scales. The final H and confidence populate the shared analysis struct, enabling indicators to act only when H departs from the neutral 0.40–0.60 band and to select trend‑following above 0.60 or mean‑reversion below 0.40.
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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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Introduction to MQL5 (Part 41): Beginner Guide to File Handling in MQL5 (III)

Introduction to MQL5 (Part 41): Beginner Guide to File Handling in MQL5 (III)

Learn how to read a CSV file in MQL5 and organize its trading data into dynamic arrays. This article shows step by step how to count file elements, store all data in a single array, and separate each column into dedicated arrays, laying the foundation for advanced analysis and trading performance visualization.
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Self Optimizing Expert Advisors in MQL5 (Part 14): Viewing Data Transformations as Tuning Parameters of Our Feedback Controller

Self Optimizing Expert Advisors in MQL5 (Part 14): Viewing Data Transformations as Tuning Parameters of Our Feedback Controller

Preprocessing is a powerful yet quickly overlooked tuning parameter. It lives in the shadows of its bigger brothers: optimizers and shiny model architectures. Small percentage improvements here can have disproportionately large, compounding effects on profitability and risk. Too often, this largely unexplored science is boiled down to a simple routine, seen only as a means to an end, when in reality it is where signal can be directly amplified, or just as easily destroyed.