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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From Basic to Intermediate: Function Pointers

From Basic to Intermediate: Function Pointers

You have probably already heard about pointers when it comes to programming. But did you know that we can use this kind of data here in MQL5? Of course, this must be done in a way that keeps us in control and avoids strange program behavior during execution. Still, because this is a feature with a very specific purpose and aimed at particular kinds of tasks, it is rare to hear anyone discuss what a pointer is and how to use it in MQL5.
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Recurrence Network Analysis (RNA) in MQL5: From Recurrence Matrices to Complex Networks

Recurrence Network Analysis (RNA) in MQL5: From Recurrence Matrices to Complex Networks

The article extends the MQL5 recurrence library to Recurrence Network Analysis (RNA) by treating recurrence matrices as adjacency matrices of undirected graphs. It implements core network metrics—clustering, transitivity, average path length, betweenness, assortativity, and density—and applies them in rolling windows for single-series RNA and Joint RNA (JRNA). A modular metrics engine and two indicators visualize the evolving network structure on MetaTrader 5 charts for practical time-series analysis.
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The MQL5 Standard Library Explorer (Part 16): Building a Regime-Adaptive Expert Advisor

The MQL5 Standard Library Explorer (Part 16): Building a Regime-Adaptive Expert Advisor

We convert the Part 15 decision‑forest classifier into a regime‑adaptive Expert Advisor that decouples statistical inference from trading authority. The EA trains on completed bars, scores each new completed bar, and confirms stable bullish, neutral, or bearish regimes before acting. It then applies spread, ownership, risk, and execution checks to authorize opening, holding, closing, or blocking a position.
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Market Simulation: Position View (XII)

Market Simulation: Position View (XII)

In this article, you will learn how to create a visual signal on your trading platform so you can determine directly on the chart whether a position is long or short, without having to open the Terminal. In addition, the article also explains how to implement a feature that improves the display when moving Take Profit and Stop Loss lines by hiding the horizontal line that follows the mouse cursor while these lines are being moved, to avoid confusion. The article provides practical insight into setting up market simulation systems.
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Making Custom Indicators for Beginners (Part 2): Fisher-style Indicator

Making Custom Indicators for Beginners (Part 2): Fisher-style Indicator

This article develops a Fisher‑style Indicator in MQL5 from first principles: normalize price within a recent high/low window, smooth and clamp the value, then apply a logarithmic transform. We cover buffer wiring, calculation‑buffer state management across bars, and seeding for stable starts. An accompanying EA implements threshold and reversal confirmation to show how to act on the signal.
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Neural Networks in Trading: Anomaly Detection in the Frequency Domain (Final Part)

Neural Networks in Trading: Anomaly Detection in the Frequency Domain (Final Part)

We continue to work on implementing the CATCH framework, which combines the Fourier transform and frequency patching mechanisms, ensuring accurate detection of market anomalies. In this article, we complete the implementation of our own vision of the proposed approaches and test the new models on real historical data.
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Dandelion Optimizer (DO)

Dandelion Optimizer (DO)

The Dandelion Optimizer (DO) turns the simple flight of a seed carried by the wind into a mathematical search strategy. The three phases — vortex rising, drift toward the center of the population, and landing along a Lévy-flight trajectory — form an elegant metaphor that yields interesting results in practice.
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A Symbol Metadata and Trading Hours Cache in MQL5: Eliminating Redundant SymbolInfo Calls in Multi-Symbol EAs

A Symbol Metadata and Trading Hours Cache in MQL5: Eliminating Redundant SymbolInfo Calls in Multi-Symbol EAs

This article presents CSymbolMetaCache, an MQL5 layer that preloads contract specifications and trading-session schedules for monitored symbols at EA startup and then serves typed getters from memory. It explains which properties are safe to cache versus dynamic ones, including the semi-dynamic tick value on cross-currency pairs, and implements an in-memory IsMarketOpen() evaluator. A benchmark quantifies latency reduction across a set of twenty symbols.
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Market Simulation: Position View (IX)

Market Simulation: Position View (IX)

In this turning-point article, we will begin to explore in greater depth the interaction between the applications we are developing to ensure full support for the replay/simulation system. Here we will analyze a problem that, on the one hand, is quite unpleasant, but on the other hand, is very interesting to explain and solve. The problem is this: how can we restore the take-profit and stop-loss lines after they have been deleted, and do so without using the terminal by performing the operation directly on the chart? At first glance, it seems simple. However, there are several obstacles that must be overcome.
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Elite Crystal Evolution Algorithm (CEO-inspired): Practical Implementation

Elite Crystal Evolution Algorithm (CEO-inspired): Practical Implementation

Experimental evaluation on standard benchmark functions reveals the advantages and limitations of directly adapting combinatorial algorithms. The article provides a detailed description of the ECEA algorithm's mechanisms and test results.
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Detecting and Visualizing Outlier Bars in MQL5 Using Modified Z-Score on OHLCV Features

Detecting and Visualizing Outlier Bars in MQL5 Using Modified Z-Score on OHLCV Features

Abnormal bars inflate mean and standard deviation estimates, distorting ATR, Bollinger Bands, and moving averages. We implement a native MQL5 indicator that detects such bars with the Modified Z-Score applied to four features: body, upper wick, lower wick, and tick volume. The indicator marks flagged bars on the chart and plots a composite score in a separate subwindow, helping you diagnose contamination in rolling-window indicators.
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Detecting Structural Breakpoints in Price Series Using CUSUM in MQL5 (Part 2): Implementing the Detector as a Native MQL5 Indicator

Detecting Structural Breakpoints in Price Series Using CUSUM in MQL5 (Part 2): Implementing the Detector as a Native MQL5 Indicator

This article benchmarks CUSUM_Breakpoint.mq5 against the Siegmund ARL₀ prediction on live‑like data. The empirical false‑alarm rate is about five times higher than theory for all tested symbols and timeframes, and confirmations show sensitivity to variance changes over mean changes. Practitioners should calibrate h and k on the target instrument's history and apply the signal to manage volatility regimes, not to infer directional shifts.
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Uncertainty as a Model (Part 1): Random Variables — The Language of Uncertainty

Uncertainty as a Model (Part 1): Random Variables — The Language of Uncertainty

The article provides a systematic overview of the theory of random variables, which serves as the basis for analyzing and modeling uncertainty in financial markets. The article covers the definitions and properties of univariate random variables, cumulative distribution functions (CDFs) and probability density functions (PDFs), as well as the differences between discrete, continuous, and mixed models. The theoretical material is based on intuitive analogies with mass and density. The appendix to this article contains practical examples of using the standard MQL5 library to calculate probabilities, quantiles, and moments of distributions. It also demonstrates the graphical capabilities of the MetaTrader 5 platform for visual data analysis by plotting PDF and CDF curves and QQ plots.
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Market Simulation (Part 23): Getting Started with SQL (VI)

Market Simulation (Part 23): Getting Started with SQL (VI)

In this article, we will see how to visualize a database and, from that, understand how it is structured. This is done by analyzing the database’s internal structure. Although this may seem unnecessary at first, it is fully justified if we really want to become database administrators. After all, some people make a living maintaining and designing databases.
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Overcoming Accessibility Problems in MQL5 Trading Tools (Part V): Gesture-Based Trading With Computer Vision

Overcoming Accessibility Problems in MQL5 Trading Tools (Part V): Gesture-Based Trading With Computer Vision

This article shows how to build a hands-free trading workflow for MetaTrader 5 by translating webcam-tracked hand gestures into MQL5 trade commands. We cover the architecture (MediaPipe/OpenCV in Python plus an MQL5 EA), gesture-to-action mapping, and interprocess communication via Global Variables or HTTP polling. You will implement the EA, execute BUY/SELL/CLOSE actions, and validate latency and reliability under real‑time conditions.
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Streaming MetaTrader 5 Trade Events to a Local HTTP Server Using WinINet in MQL5

Streaming MetaTrader 5 Trade Events to a Local HTTP Server Using WinINet in MQL5

An MQL5 implementation sends trade lifecycle events to a local HTTP service through WinINet with a reusable session and per-request handles. The trade callback only enqueues JSON and returns, while a 500 ms timer drains the queue and retries failed posts, preserving order. A three-stage log policy keeps the Experts tab clear during downtime and summarizes recovery.
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Butterfly Optimization Algorithm (BOA)

Butterfly Optimization Algorithm (BOA)

The article discusses the Butterfly Optimization Algorithm, which is based on modeling foraging using the sense of smell. We will analyze the original formulas, identify and correct errors in motion equations, add a mechanism for maintaining population diversity, and present the test results.
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Measuring What Matters (Part 2): Building the Covariance Matrix: Eigenvalue Decomposition and Risk Factor Analysis in MQL5

Measuring What Matters (Part 2): Building the Covariance Matrix: Eigenvalue Decomposition and Risk Factor Analysis in MQL5

In Part 2, we introduce a reusable CCovarianceMatrix class that computes and stores a covariance matrix from raw return series using MQL5's native Cov() method. We verify symmetry, print a labeled matrix grid, and call Eig() to obtain eigenvalues and eigenvectors. Readers see how symbols co-move and which factors drive variance, enabling clearer portfolio diagnostics and reuse in scripts or EAs.
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Building Your Personal Expert Advisor (Part 4): Risk Management III—Risk Models and Order Execution

Building Your Personal Expert Advisor (Part 4): Risk Management III—Risk Models and Order Execution

The EA now defines risk by percentage, fixed cash, or fixed lot and can measure percentage against balance or equity. It supports market, limit, and stop orders, sizes from the planned entry, and enforces spread‑aware stop minima. Additional safeguards include downward volume rounding, explicit handling when the minimum lot exceeds target risk, and pending‑order distance/expiry checks, organized under a Plan–Validate–Execute structure.
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From Cloud to Complex: The Vietoris-Rips Filtration in MQL5

From Cloud to Complex: The Vietoris-Rips Filtration in MQL5

We turn a price-embedded point cloud into a Vietoris–Rips filtration and its boundary matrix. The article enumerates vertices, edges, and triangles with filtration values, sorts them in entry order, and builds O(1) vertex/edge lookups. You get MQL5 classes CTDARips and CTDABoundary and a sparse Z/2 boundary suitable for the next-step persistence reduction.
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Automating Classic Market Methods in MQL5 (Part 8): Ed Seykota's Trend Following System

Automating Classic Market Methods in MQL5 (Part 8): Ed Seykota's Trend Following System

The article presents a full MQL5 implementation of a multi-symbol trend system: dual EMA crossovers for entries, ADX to avoid ranges, ATR to normalize position size, and a heat monitor to cap total portfolio risk. We explain the architecture, calculation details, and entry/exit logic on daily bars. The result is a practical EA template for systematic, risk-aware portfolio trading.
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Building a Compile-Time Unit Testing Framework in MQL5 Using Preprocessor Assertions

Building a Compile-Time Unit Testing Framework in MQL5 Using Preprocessor Assertions

MQL5 lacks native unit testing, so utility bugs in lot sizing, pip value, and normalization often slip into production. This article presents a zero‑dependency framework built from preprocessor assertion macros, interface‑based suites, and a central runner/formatter. It runs as a script in OnStart, executes deterministic tests, and prints pass/fail summaries to the Experts tab to catch rounding, boundary, and error-handling defects before deployment.
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Combining 3D Bars, Quantum Computing, and Machine Learning into a Unified Trading System

Combining 3D Bars, Quantum Computing, and Machine Learning into a Unified Trading System

The article presents the full integration of the 3D-bar module into a quantum-enhanced trading system for forecasting the movement of currency pairs. The system combines stationary four-dimensional features, an 8-qubit quantum encoder, and CatBoost gradient boosting with 52+ features. The system is implemented in Python using MetaTrader 5, Qiskit, CatBoost, and optional integration with the Llama 3.2 LLM for interpreting forecasts.
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Building a Swing-Based Volume Profile Indicator in MQL5

Building a Swing-Based Volume Profile Indicator in MQL5

This article presents a swing-based volume profile indicator in MQL5 that analyzes platform tick volume within completed high-to-low and low-to-high legs. It confirms swing points, partitions each leg's range into ATR(200)‑adaptive price bins, distributes tick volume, and marks the Point of Control. The indicator draws a ZigZag and renders the profile on chart rectangles, helping you study volume concentration within each swing relative to price structure.
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MQL5 Wizard Techniques you should know (Part 91): Using Skip Lists and a Hopfield Network in a Custom Trailing Class

MQL5 Wizard Techniques you should know (Part 91): Using Skip Lists and a Hopfield Network in a Custom Trailing Class

For our next Exploration on notions that are testable with the MQL5 Wizard we examine if Skip Lists and the Hopfield Network can give us a profit-guarding trailing strategy. Trailing Stop Management, as already argued, can be overlooked in most trading systems at the expense of Entry Signals or even Money Management. Trailing stops can make all the difference in certain situations such as trending markets, and thus we test this out with GBPJPY.
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From Basic to Intermediate: Struct (V)

From Basic to Intermediate: Struct (V)

In this article, we will explore how to overload structural code. I know it can be quite challenging to understand at first, especially if you're seeing it for the first time. It is very important that you grasp these concepts and understand them well before attempting to delve into more complex and elaborate topics.
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From Static MA to Adaptive Filtering (Part 1): Introducing SAMA with NLMS in MQL5

From Static MA to Adaptive Filtering (Part 1): Introducing SAMA with NLMS in MQL5

This article introduces the Self-Adaptive Moving Average (SAMA), an adaptive filter leveraging the Normalized Least Mean Squares (NLMS) algorithm. It explores why fixed-period averages fail, how NLMS adapts bar by bar, and the engineering protections required for production. This conceptual and mathematical foundation prepares you for the MQL5 code implementation in Part 2.
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Market Simulation: Getting Started with SQL in MQL5 (V)

Market Simulation: Getting Started with SQL in MQL5 (V)

In the previous article, I showed how to proceed in order to add a query mechanism. This was needed so that, inside MQL5 code, you could fully use SQL and retrieve results using an SQL SELECT query. But there is still one last function we need to implement. This is the DatabaseReadBind function. Since understanding it properly requires a slightly more detailed explanation, it was decided to cover it not in the previous article, but in today's article. So, since the topic will be fairly extensive, let us proceed directly to the next section.
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LLM-Based Trading Agent with Embedded Top Trader Philosophy

LLM-Based Trading Agent with Embedded Top Trader Philosophy

The article provides a critical analysis of an LLM strategy in which forecasting the direction is separated from trading decisions, and demonstrates why this leads to a disconnect between metrics and PnL. We will describe procedures for dataset balancing, feature engineering, prompt and response preparation, fine-tuning configuration in Ollama, and reliable parsing. Backtesting and forward testing reveal systematic degradation. The practical conclusion is that the problem must be formulated as a direct optimization of trading outcomes.
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From Option Chain to 3D Volatility Surface in MetaTrader 5

From Option Chain to 3D Volatility Surface in MetaTrader 5

This article walks through creating an MT5 indicator that ingests option chains from native symbols or CSV, inverts prices to implied volatility via a hybrid Newton–Raphson/bisection method, and assembles a clean strike–expiry grid. It then renders a shaded, rotatable 3D surface with the platform's DirectX layer, enabling clear, in-terminal analysis of skew and term structure using live or file-based data.
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Neural Networks in Trading: Decomposition Instead of Scaling (Conclusion)

Neural Networks in Trading: Decomposition Instead of Scaling (Conclusion)

We invite you to learn about an algorithm for decomposing a time series into meaningful layers and using them to build a parsimonious model. We systematically present the architecture, the practical implementation in MQL5/OpenCL, and real-world tests using historical market data.
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CSV Data Analysis (Part 1): CSV Export Engine for MQL5 Multi-Core Optimizations

CSV Data Analysis (Part 1): CSV Export Engine for MQL5 Multi-Core Optimizations

Multi-core optimization in MetaTrader 5 can silently drop results when parallel agents contend for the same CSV file. A reusable MQL5 export engine applies an iteration-based spin-lock to acquire the file handle reliably and append rows without loss. It persists custom metrics such as the Sortino Ratio, average trade duration, and signal-quality measures (lag and whipsaws) into a consolidated CSV for downstream analysis.
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Comparing Trade Return Distributions with Mann-Whitney U in MQL5

Comparing Trade Return Distributions with Mann-Whitney U in MQL5

A native, dependency-free MQL5 implementation of the Mann-Whitney U test for comparing trade returns across two market regimes. It details rank calculation, tie correction, and a normal-approximation p-value, and pairs the test with a CCanvas box-and-whisker chart and a trade-history extraction script. A verification script is included, and the limits of the normal approximation and independence assumptions are clearly stated for informed use.
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Learnable Curves, Not Weights: A Kolmogorov-Arnold Network from Scratch

Learnable Curves, Not Weights: A Kolmogorov-Arnold Network from Scratch

This article builds a Kolmogorov–Arnold Network (KAN) in MQL5, where every edge carries a learnable B‑spline curve rather than a scalar weight. We construct the spline basis, assemble edges and a layer, and fit all coefficients by ridge‑regularized least‑squares in a single solve. The model is delivered as an indicator that visualizes the learned curves and an Expert Advisor that acts on the prediction, providing an interpretable, reusable codebase.
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Market Simulation: Position View (XIII)

Market Simulation: Position View (XIII)

In this article, we will look at how to easily implement an indicator that shows whether a position is generating a profit or a loss. The procedure is simple and effective. Even without in-depth expertise, this indicator will allow you to easily recognize when to close a position. This way, you will avoid unexpected results, since the calculation reflects the actual outcome you would get if you closed the position.
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From Basic to Intermediate: Working with Files in the MetaTrader 5 Sandbox

From Basic to Intermediate: Working with Files in the MetaTrader 5 Sandbox

Do you know what a sandbox is? Do you know how to work with it? If the answer to either of these questions is “no”, read this article to understand the basic operating principle of a sandbox. You will also understand why MetaTrader 5 uses a sandbox to protect the integrity of some of its internal data. The material presented here is purely instructional. Under no circumstances should you treat the application as a final product whose purpose is anything other than studying the concepts presented.
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Building a Gold Volatility Regime Monitor from Options Data in MQL5

Building a Gold Volatility Regime Monitor from Options Data in MQL5

A practical bridge from the options market into MetaTrader 5 for gold. We compute near-the-money implied volatility by solving Black-Scholes from quoted prices, compare it with 30-day realized volatility, and use the ratio as a regime proxy. A Python feed publishes the value, an MQL5 script consumes it with WebRequest, and a background service keeps a panel current and alerts on changes. Source code for all parts is provided.
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Persistent Homology in MQL5: The Reduction Algorithm and the Persistence Diagram

Persistent Homology in MQL5: The Reduction Algorithm and the Persistence Diagram

We complete persistent homology for MQL5 by reducing the Vietoris–Rips boundary matrix to a persistence diagram. The article implements Z/2 column reduction (CTDAReduction), a diagram container with analytics (CTDADiagram), and a facade that runs the six-stage pipeline in one call (CTDA). Outputs are cross-checked against Ripser to numerical agreement, enabling reliable diagram-based metrics.
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Building Your Personal Expert Advisor (Part 5): Risk Management IV—Basket Risk and Strategy-Specific Sizing

Building Your Personal Expert Advisor (Part 5): Risk Management IV—Basket Risk and Strategy-Specific Sizing

Part 5 moves risk control from single trades to a basket-level framework. The EA aggregates its own positions, computes volume‑weighted entry, floating P/L including swap, and used margin, then enforces limits on combined loss, margin, position count, and time underwater, while logging maximum adverse excursion. A companion mean‑reversion EA demonstrates target‑based sizing and caps on implied risk that remains hidden when trades are evaluated in isolation.
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Machine Learning in Pure MQL5 (Part 1): Logistic Regression from Scratch with SGD

Machine Learning in Pure MQL5 (Part 1): Logistic Regression from Scratch with SGD

The series develops machine learning in 100% native MQL5 with no external dependencies. Part 1 delivers logistic regression from first principles: a CLogReg class with standardization, a stable sigmoid, SGD training, and model persistence, plus a script that builds ATR-normalized features, labels the next bar, and tests out-of-sample against a baseline. Readers get a compact include file and a clear template for leakage-free evaluation.