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 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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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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Neural Networks in Trading: LSTM Optimization for Multivariate Time Series Forecasting (Final Part)

Neural Networks in Trading: LSTM Optimization for Multivariate Time Series Forecasting (Final Part)

We continue to implement the DA-CG-LSTM framework, which offers innovative methods for time series analysis and forecasting. The use of CG-LSTM and dual attention allows for more accurate detection of both long-term and short-term dependencies in data, which is particularly useful for working with financial markets.
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News Filtering with MetaTrader 5 Economic Calendar and CSV Fallback

News Filtering with MetaTrader 5 Economic Calendar and CSV Fallback

This article presents a self-contained news filter module for MetaTrader 5 built on the platform's economic calendar API. It implements symbol-to-currency mapping, pre- and post-event trading pauses, and optional position size reduction on high-impact days, with a CSV-based fallback for the Strategy Tester. A demo EA and live chart dashboard show integration and verification in both live and backtest environments.
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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MQL5 Trading Tools (Part 18): Rounded Speech Bubbles/Balloons with Orientation Control

MQL5 Trading Tools (Part 18): Rounded Speech Bubbles/Balloons with Orientation Control

This article shows how to build rounded speech bubbles in MQL5 by combining a rounded rectangle with a pointer triangle and controlling orientation (up, down, left, right). It details geometry precomputation, supersampled filling, rounded apex arcs, and segmented borders with an extension ratio for seamless joins. Readers get configurable code for size, radii, colors, opacity, and thickness, ready for alerts or tooltips in trading interfaces.
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MetaTrader 5 Machine Learning Blueprint (Part 16): Nested CV for Unbiased Evaluation

MetaTrader 5 Machine Learning Blueprint (Part 16): Nested CV for Unbiased Evaluation

The article presents a V-in-V nested cross-validation pipeline for financial data that breaks leakage at three decision points: hyperparameter search, calibration, and final evaluation. A temporal three‑zone split isolates an inner walk‑forward search with the 1‑SE rule from an outer walk‑forward or CPCV evaluation, while OOF isotonic calibration is fitted independently. The resulting UnifiedValidationCalibrator delivers unbiased out‑of‑sample scores and well‑calibrated probabilities for deployment.
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MQL5 Custom Symbols: Creating a 3D Bars Symbol

MQL5 Custom Symbols: Creating a 3D Bars Symbol

The article provides a detailed guide to creating the innovative 3DBarCustomSymbol.mq5 indicator, which generates custom symbols in MetaTrader 5 that combine price, time, volume, and volatility into a single three-dimensional representation. The mathematical foundations, system architecture, practical aspects of implementation and application in trading strategies are considered.
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Backtracking Search Algorithm (BSA)

Backtracking Search Algorithm (BSA)

What if an optimization algorithm could remember its past journeys and use that memory to find better solutions? BSA does just that – balancing exploration with revisiting the tried and true. In this article, we reveal the secrets of the algorithm. A simple idea, minimum parameters and a stable result.
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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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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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Implementing Partial Position Closing in MQL5

Implementing Partial Position Closing in MQL5

This article develops a class for managing partial position closing in MQL5 and then integrates it into an Order Blocks Expert Advisor. It also presents test results comparing the strategy with and without partial position closing, and analyzes the conditions under which this approach can help provide and maximize profit. In conclusion, partial position closing can be highly beneficial in trading strategies, especially those focused on wider price movements.
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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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Meta-Labeling the Classics (Part 1): Filtering and Sizing RSI Trades

Meta-Labeling the Classics (Part 1): Filtering and Sizing RSI Trades

RSI accumulates losses in trending conditions by firing at every threshold crossing regardless of market regime. A Random Forest secondary classifier trained on 12 contextual features — RSI momentum slope, EMA50 trend velocity, ATR-normalised trend stretch, and nine others — filters raw signals and scales position size by classifier confidence on EURUSD H1. Results compare plain RSI, meta-filtered RSI, and bet-sized RSI across a 16-month out-of-sample period with per-trade metrics and drawdown diagnostics.
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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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Implementation of a table model in MQL5: Applying the MVC concept

Implementation of a table model in MQL5: Applying the MVC concept

In this article, we look at the process of developing a table model in MQL5 using the MVC (Model-View-Controller) architectural pattern to separate data logic, presentation, and control, enabling structured, flexible, and scalable code. We consider implementation of classes for building a table model, including the use of linked lists for storing data.
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Algorithmic Arbitrage Trading Using Graph Theory

Algorithmic Arbitrage Trading Using Graph Theory

In this article, triangular arbitrage is presented as a problem of finding cycles in a directed graph, where the vertices are currencies and the edges are currency pairs with weight rates. Profitable cycle: product of weights >1. Our Floyd-Warshall and DFS algorithms find optimal currency exchange paths that return to the starting point with a profit.
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Market Simulation (Part 24): Getting Started with SQL (VII)

Market Simulation (Part 24): Getting Started with SQL (VII)

In the previous article, we completed the necessary introduction to SQL. And, in my opinion, we properly clarified what we wanted to show and explain about SQL. This was done so that anyone who comes to look at the market replay/simulation system being built can at least get an idea of what may be happening there. The point is that there is no sense in programming things that SQL handles perfectly.
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Price-Driven CGI Model: Advanced Data Post-Processing and Implementation

Price-Driven CGI Model: Advanced Data Post-Processing and Implementation

In this article, we will explore the development of a fully customizable Price Data export script using MQL5, marking new advancements in the simulation of the Price Man CGI Model. We have implemented advanced refinement techniques to ensure that the data is user-friendly and optimized for animation purposes. Additionally, we will uncover the capabilities of Blender 3D in effectively working with and visualizing price data, demonstrating its potential for creating dynamic and engaging animations.
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MQL5 Trading Toolkit (Part 7): Expanding the History Management EX5 Library with the Last Canceled Pending Order Functions

MQL5 Trading Toolkit (Part 7): Expanding the History Management EX5 Library with the Last Canceled Pending Order Functions

Learn how to complete the creation of the final module in the History Manager EX5 library, focusing on the functions responsible for handling the most recently canceled pending order. This will provide you with the tools to efficiently retrieve and store key details related to canceled pending orders with MQL5.
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Mastering Log Records (Part 3): Exploring Handlers to Save Logs

Mastering Log Records (Part 3): Exploring Handlers to Save Logs

In this article, we will explore the concept of handlers in the logging library, understand how they work, and create three initial implementations: Console, Database, and File. We will cover everything from the basic structure of handlers to practical testing, preparing the ground for their full functionality in future articles.
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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.
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MQL5 Trading Tools (Part 30): Class-Based Tool Palette Sidebar

MQL5 Trading Tools (Part 30): Class-Based Tool Palette Sidebar

We refactor the Tools Palette from a flat, function-based panel into a modular, class-driven sidebar in MQL5. The design introduces supersampled canvas rendering for anti-aliased shapes, theme control, a category registry, snap alignment, and selective corner rounding. The result is a reusable, scalable sidebar foundation that you can extend with tool selection, dragging, and fly-out menus in future steps.
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Mastering Log Records (Part 8): Error Records That Translate Themselves

Mastering Log Records (Part 8): Error Records That Translate Themselves

In this eighth installment of the Mastering Log Records series, we explore the implementation of multilingual error messages in Logify, a powerful logging library for MQL5. You’ll learn how to structure errors with context, translate messages into multiple languages, and dynamically format logs by severity level. All of this with a clean, extensible, and production-ready design.
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Price Action Analysis Toolkit Development (Part 71): Weekend Gap Structure Mapping in MQL5

Price Action Analysis Toolkit Development (Part 71): Weekend Gap Structure Mapping in MQL5

The article delivers an object-based MQL5 implementation that detects weekend gaps from time discontinuities and renders them directly on the chart. It manages graphical objects, tracks state transitions (fresh, partial, reaction, filled), and preserves completed gaps as historical zones. The result is a reproducible framework for monitoring how price revisits and fills weekend gap structures.
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Population optimization algorithms: Resistance to getting stuck in local extrema (Part I)

Population optimization algorithms: Resistance to getting stuck in local extrema (Part I)

This article presents a unique experiment that aims to examine the behavior of population optimization algorithms in the context of their ability to efficiently escape local minima when population diversity is low and reach global maxima. Working in this direction will provide further insight into which specific algorithms can successfully continue their search using coordinates set by the user as a starting point, and what factors influence their success.
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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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RiskGate: Centralized Risk Management for Multiple EAs

RiskGate: Centralized Risk Management for Multiple EAs

Many MetaTrader 5 setups run several EAs on one account, so risk gets fragmented and correlated exposure slips through. The article introduces RiskGate, a centralized Service that evaluates EA intents account‑wide: EAs send a JSON signal, the Service returns approved, lot and reason. You will see the client/server wiring, example rules (daily loss, exposure and correlation caps), unit‑tested handler design, and an EA example. The result is consistent portfolio‑level risk with simpler EAs.
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MQL5 Trading Tools (Part 28): Filling Sweep Polygons for Butterfly Curve in MQL5

MQL5 Trading Tools (Part 28): Filling Sweep Polygons for Butterfly Curve in MQL5

We expand the capabilities of the MetaTrader 5 butterfly curve canvas by adding multi-layered wing fills, vein lines, scale dots, and a full body (abdomen, thorax, head, eyes, antennae). This article implements polygon fills with vertical and radial gradients, as well as filled circles and ellipses, all using supersampling antialiasing. You will also receive reusable MQL5 helper functions and a rendering order that transforms a simple curve into a customizable, detailed chart illustration.
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A Practical Kalman Filter Price Smoother in MQL5: Adaptive Noise Estimation Without External Libraries

A Practical Kalman Filter Price Smoother in MQL5: Adaptive Noise Estimation Without External Libraries

Fixed-weight moving averages introduce regime-insensitive lag. This work presents an adaptive scalar Kalman filter indicator in native MQL5 that estimates process noise Q from rolling return variance and measurement noise R from rolling price variance, with floor clamps for stability, and recomputes the Kalman Gain on every bar. The chart-overlay output is benchmarked against a 20-period EMA using MAE, RMSE, lag, and smoothness metrics to quantify tracking and noise suppression.
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Overcoming Accessibility Problems in MQL5 Trading Tools (Part IV): Remote voice trading

Overcoming Accessibility Problems in MQL5 Trading Tools (Part IV): Remote voice trading

Learn a practical way to execute MetaTrader 5 trades from Telegram voice notes using a Python middleware and an MQL5 EA acting as an HTTP client. The article covers architecture, WebRequest polling, in-memory queuing, JSON parsing with null-terminator stripping, and a constrained command grammar with a 0.001-lot default. You will configure the environment and validate round‑trip latency suitable for mobile data connections.
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Neural Networks in Trading: LSTM Optimization for Multivariate Time Series Forecasting (DA-CG-LSTM)

Neural Networks in Trading: LSTM Optimization for Multivariate Time Series Forecasting (DA-CG-LSTM)

This article introduces the DA-CG-LSTM algorithm, which offers new approaches to time series analysis and forecasting. It explains how innovative attention mechanisms and model flexibility can improve forecast accuracy.
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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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MQL5 Wizard Techniques you should know (Part 90): Fenwick Tree Money Management with 1D CNN in MQL5

MQL5 Wizard Techniques you should know (Part 90): Fenwick Tree Money Management with 1D CNN in MQL5

This article implements a Fenwick Tree (Binary Indexed Tree) for volume-aware money management inside an MQL5 Wizard Expert Advisor. We structure cumulative volume in O(log n) and apply four scaling modes—linear, conservative, aggressive, and mean-reversion—optionally gated by a lightweight 1D CNN. Practical tests compare the algorithm alone versus the CNN‑filtered approach to illustrate adaptive lot sizing and risk control under varying volume topologies.
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The View component for tables in the MQL5 MVC paradigm: Base graphical element

The View component for tables in the MQL5 MVC paradigm: Base graphical element

The article covers the process of developing a base graphical element for the View component as part of the implementation of tables in the MVC (Model-View-Controller) paradigm in MQL5. This is the first article on the View component and the third one in a series of articles on creating tables for the MetaTrader 5 client terminal.
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Custom Debugging and Profiling Tools for MQL5 Development (Part II): Profiling EAs and Testing Trading Logic

Custom Debugging and Profiling Tools for MQL5 Development (Part II): Profiling EAs and Testing Trading Logic

We build a compact profiler that records calls, min/max/average times, and slow-call counts to CSV, and a simple test runner that writes deterministic pass/fail reports. The article explains where to place measurements in an EA, how to sample ticks, and how to keep pure calculations testable. Running the script first and the profiling EA second provides repeatable evidence for regression analysis.
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Market Simulation (Part 22): Getting Started with SQL (V)

Market Simulation (Part 22): Getting Started with SQL (V)

Before you give up and decide to abandon learning SQL, allow me to remind you, dear readers, that here we are still using only the most basic elements. We have not yet looked at some of SQL's capabilities. Once you understand them, you will see that SQL is far more practical than it seems. Although, most likely, we will eventually change the direction of what we are building, because the creation process is dynamic. We will show a little more about creating different things in SQL, because this is truly important and useful for you. Simply thinking that you are more capable than an entire community of programmers and developers will only lead to wasted time and opportunities. Do not worry, because what comes next will be even more interesting.
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From Basic to Intermediate: Floating point

From Basic to Intermediate: Floating point

This article is a brief introduction to the concept of floating-point numbers. Since this text is very complex please, read it attentively and carefully. Do not expect to quickly master the floating-point system. It only becomes clear over time, as you gain experience using it. But this article will help you understand why your application sometimes produces results different from what you expect.
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Automating Classic Market Methods in MQL5 (Part 3): Stan Weinstein Stage Analysis

Automating Classic Market Methods in MQL5 (Part 3): Stan Weinstein Stage Analysis

This article presents a complete Expert Advisor built around Stan Weinstein's Stage Analysis method. The EA classifies the market into one of four stages using the 30-week moving average slope and position and volume behavior, then trades only Stage 2 breakouts long and Stage 4 breakdowns short. It explains each stage, how to detect it programmatically, and why the method's discipline—trading only in the correct stage—is what produces the edge.
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MQL5 Wizard Techniques you should know (Part 29): Continuation on Learning Rates with MLPs

MQL5 Wizard Techniques you should know (Part 29): Continuation on Learning Rates with MLPs

We wrap up our look at learning rate sensitivity to the performance of Expert Advisors by primarily examining the Adaptive Learning Rates. These learning rates aim to be customized for each parameter in a layer during the training process and so we assess potential benefits vs the expected performance toll.