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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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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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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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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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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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.
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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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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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Encoding Candlestick Pattern (Part 6): Developing the Encoded Sequence Indicator

Encoding Candlestick Pattern (Part 6): Developing the Encoded Sequence Indicator

An on-chart MQL5 indicator generates a live stream of encoded candlestick symbols and a frequency report for the last N bars. It supports color customization and type filtering, and uses A/a, H/h, E/e, G/g, D, and N/n classifications. Traders can quickly review occurrences and common sequences directly on the chart.
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Hypothesis Testing for Trading Strategies — Proving Whether Your Edge is Real

Hypothesis Testing for Trading Strategies — Proving Whether Your Edge is Real

Net profit and win rate do not tell you if a strategy's edge is statistically real. This MQL5 toolkit analyzes return series built from price data or deal history and reports t‑statistics, p‑values, and confidence intervals using one-sample and Welch t‑tests, the Mann–Whitney U test, and volatility‑regime analysis to support evidence‑based trading decisions.
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Beetle Swarm Optimization (BSO)

Beetle Swarm Optimization (BSO)

We consider a BAS+PSO (BSO) hybrid, where BAS provides a local direction signal and PSO facilitates the exchange of best solutions within the swarm. The article presents a mathematical model, pseudocode, an implementation of the class in MQL5, and test results from a standard test bench. This material allows reproducing the algorithm, configuring its parameters, and understanding how three objective-function evaluations per iteration affect efficiency.
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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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Persistent Key-Value Store in MQL5: Using Flat Files as a Lightweight Database for EA State

Persistent Key-Value Store in MQL5: Using Flat Files as a Lightweight Database for EA State

A lightweight persistence design lets EAs retain counters, flags, and timestamps between terminal restarts. Using only MQL5, CPersistentStore writes a human-readable key=value file in MQL5/Files and serves reads from a CHashMap write-through cache via a typed API. The article analyzes O(1)/O(n) operations, partial‑write risks, and lack of locking, compares with GlobalVariables/SQLite, and provides a demo that reloads state deterministically.
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Market Simulation: Position View (XVII)

Market Simulation: Position View (XVII)

In the previous article, we configured the indicator to display the financial result. However, not everyone likes using this display mode. The reasons differ from one trader to another, although in some cases they seem quite reasonable and justified to me. Adapting the code to provide this capability is by no means one of the most difficult tasks. It's actually pretty simple. In this article, we'll look at how to do this.
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Neural Networks in Trading: The Temporal Query Model (Conclusion)

Neural Networks in Trading: The Temporal Query Model (Conclusion)

We are pleased to present the final stage of the TQNet framework’s development and testing, where theory meets real-world trading practice. We will move from historical training to a stress test using recent market data, evaluating the model's robustness and accuracy. The final results are not just dry statistics, but also a clear demonstration of the practical value of the proposed approach.
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Bidirectional LSTM and Quantum Computing for Predicting the Direction of Price Movement

Bidirectional LSTM and Quantum Computing for Predicting the Direction of Price Movement

The article presents a reproducible implementation of a hybrid quantum-neural network model for algorithmic trading on Forex without using real quantum hardware. A fixed three-qubit quantum circuit in IBM Qiskit converts sliding-window statistics (mean returns, volatility, and range) into a probability distribution, from which seven quantum metrics are calculated. These features are integrated into a bidirectional LSTM architecture with regularization and mechanisms to address class imbalance, including focal loss and a sampler.
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Ecological Cycle Optimizer (ECO)

Ecological Cycle Optimizer (ECO)

The ECO (Ecological Cycle Optimizer) algorithm offers an interesting metaphor for applying the concept of the ecological cycle to the field of metaheuristic optimization. The idea of dividing a population into trophic levels — producers, herbivores, carnivores, omnivores, and decomposers — creates a hierarchical search structure, in which each group contributes to the overall optimization process.
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Survival Analysis for Trade Exits: A Discrete-Time Competing-Risks Model in MQL5

Survival Analysis for Trade Exits: A Discrete-Time Competing-Risks Model in MQL5

Fixed exits ignore state changes while a trade is open. We implement a discrete-time competing-risks model entirely in MQL5, estimate cause-specific hazards for take-profit and stop-loss via Newton–Raphson on a person-period dataset with time-varying features, and turn cumulative incidence into a bar-by-bar hold-or-close rule, then test it against fixed take-profit/stop-loss with identical entry logic.
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Neural Networks in Trading: Decomposition Instead of Scaling — Building Modules

Neural Networks in Trading: Decomposition Instead of Scaling — Building Modules

In this article, we continue our hands-on exploration of SSCNN — a next-generation architectural solution capable of processing fragmented time series. Instead of blind scaling — smart modularity, attention to detail, and targeted normalization. Step by step, we are creating computational blocks in the MQL5 environment and laying the foundation for reliable predictive analysis.
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Developing Smart Chart Objects in MQL5 (Part 2): Automating Trendline Discovery and Lifecycle Management

Developing Smart Chart Objects in MQL5 (Part 2): Automating Trendline Discovery and Lifecycle Management

Learn how Smart Trendline Manager separates creation from lifecycle control while handling both manual and auto-generated trendlines. It demonstrates discovery, registration, proximity and touch handling, bounce/break confirmation, post-break resurrection, expiration, and state-driven visualization. This gives you a consistent, configurable way to manage multiple lines through one orchestrated update process.
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MQL5 Wizard Techniques you should know (Part 96): Using Wavelet Thresholding and LSTM Network in a Custom Money Management Class

MQL5 Wizard Techniques you should know (Part 96): Using Wavelet Thresholding and LSTM Network in a Custom Money Management Class

In this article we consider a custom MQL5 Wizard class that processes Money Management. Our custom class is labelled ‘CMoneyWaveletLSTM’, and is developed by combining the Wavelet Thresholding algorithm with an LSTM network. As has been the case throughout these series, the developed model is testable with MQL5 Wizard-Assembled Expert Advisors that can be tuned with different trailing stops and entry Signals classes. We maintain our entry Signal, as in past articles as the built-in 'Envelopes' class and the RSI class.
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From Basic to Intermediate: Like Bubbles

From Basic to Intermediate: Like Bubbles

This article will explain a very simple and easy-to-understand mechanism whose purpose is to sort any array. In it, we will see that the result obtained does not always meet expectations, so the implementation itself will need to be adapted to achieve the desired results.
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Market Simulation: Getting started with SQL in MQL5 (I)

Market Simulation: Getting started with SQL in MQL5 (I)

In today's article we will begin studying the use of SQL in MQL5 code. We will also look at how to create a database. Or, more precisely, how to create a SQLite database file using the features built into MQL5. We will also see how to create a table, and then how to establish a relationship between tables by using primary and foreign keys. All of this, once again, will be done with MQL5. We will see how easy it is to create code that can later be migrated to other SQL implementations by using a class that helps hide the implementation being created. And, most importantly, we will see that at various points we may face the risk that something will go wrong when using SQL. This happens because, in MQL5 code, SQL code will always be placed inside a string.
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Building Your Personal Expert Advisor (Part 3): Risk Management II—Margin and Allowable Risk

Building Your Personal Expert Advisor (Part 3): Risk Management II—Margin and Allowable Risk

Risk-based lot sizing can still exceed what free margin allows. The article adds a margin-aware cap using OrderCalcMargin(), an optional adaptive cap that scales with ACCOUNT MARGIN LEVEL, and a single pre-trade validation gate that unifies position limits, risk sizing, and margin checks. Readers get concrete code to prevent order rejections and over-committing margin, with clear logs when a trade is reduced or skipped.
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Hierarchical Risk Parity: A Robust Portfolio Allocator and Expert Advisor

Hierarchical Risk Parity: A Robust Portfolio Allocator and Expert Advisor

We implement a Hierarchical Risk Parity allocator in MQL5 as a single class, validate each stage against an independent Python reference, and package it in a rebalancing Expert Advisor. The pipeline covers returns, covariance/correlation, clustering, quasi-diagonalization, and recursive bisection, and contrasts HRP with Markowitz on stressed data. You finish with a verified allocator and an EA ready for basket-level testing.
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MQL5 Wizard Techniques you should know (Part 99): Using a KD-Tree and an Echo State Network in a Custom Money Management Class

MQL5 Wizard Techniques you should know (Part 99): Using a KD-Tree and an Echo State Network in a Custom Money Management Class

This article lays out 'CMoneyKDTreeESN' custom money management class usable with the MQL5 Wizard, that combines the KD-Tree algorithm and the Echo State Network. We use the KD-Tree on log returns and ATR to give us a risk score, while the ESN tracks recent flow to give us a bounded lot size multiplier. Our class is usable in a variety of Wizard assembled Expert Advisors as shown here with the Envelopes and RSI signals, with a broad objective of modulating exposure in high-volatility and tail-risk environments.
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Building a Divergence System (Part IV): Creating a Reusable Divergence Engine for MQL5

Building a Divergence System (Part IV): Creating a Reusable Divergence Engine for MQL5

The article extracts the series' divergence logic into DivergenceEngine.mqh, a reusable header for MQL5 indicators and Expert Advisors. It details the struct-based design, oscillator options (MPO4 or RSI), pivot and state handling, and the minimal access API. A Parabolic SAR EA demonstrates integration by adapting the acceleration factor from the detected divergence, providing a clear pattern you can reuse without duplicating code.
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Exponentially Weighted Covariance Matrix in MQL5: Building an Adaptive Correlation Monitor for Multi-Symbol EAs

Exponentially Weighted Covariance Matrix in MQL5: Building an Adaptive Correlation Monitor for Multi-Symbol EAs

This article builds a constant-memory EW covariance engine and a chart heatmap for monitoring cross-symbol correlations in MQL5. CEWCovariance updates in O(N²) time per bar and exposes covariance/correlation accessors; CHeatmapRenderer shows a five‑symbol matrix with values and colors. You will learn λ-to‑window mapping, how to set a meaningful min_obs warm‑up, and how to size the variance guard epsilon for real FX M1 data.
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Implementing a Fluent Interface Builder Pattern for MQL5 Order Construction

Implementing a Fluent Interface Builder Pattern for MQL5 Order Construction

Manual population of MqlTradeRequest leaves cross-field rules unchecked, creating silent misconfigurations at execution time. A fluent COrderBuilder for MQL5 adds pointer-based method chaining, per-field validation, and directional SL/TP checks against broker stop‑level constraints. Its Send() method runs a four-stage gate—flag completeness, cross-field consistency, OrderCheck(), then OrderSend()—so configuration errors are caught early and order code stays clear and reusable.
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Beyond GARCH (Part V): Fitting the Multifractal Spectrum in MQL5

Beyond GARCH (Part V): Fitting the Multifractal Spectrum in MQL5

This article builds the Spectrum Fitter: from tau(q) we compute f(alpha) with a discrete Legendre transform, then fit Normal, Binomial, Poisson, and Gamma spectra under box constraints using BLEIC. The best model by SSE is selected, and its parameters (eg, alpha min, alpha max or alpha_0, gamma) become the cascade inputs for multifractal simulation.
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Enhancing the MQL5 Portfolio Analyzer Dashboard: Active Mitigation, Data Exports, and AI Integration

Enhancing the MQL5 Portfolio Analyzer Dashboard: Active Mitigation, Data Exports, and AI Integration

This article delivers active drawdown monitoring, automated mitigation rules, Excel XML data export, and AI-assisted review for the Portfolio Analyzer dashboard. It visualizes strategy-level drawdowns over time, enforces limits by closing positions and optionally disabling AutoTrading, and generates structured spreadsheets from trade records. A hybrid MQL5-Python approach runs the external review script directly from the terminal, supporting practical risk control and transparent reporting.
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Markov Chains in Trading and Price Forecasting

Markov Chains in Trading and Price Forecasting

In this article, we will examine how to build and apply Markov chains in market conditions: from selecting states and counting transitions to generating forecasts of trajectories and levels. We will also see how Markov chains can be applied to qualitative and quantitative data, ways to account for rare events, and the impact of the forecast horizon. Examples are provided using prices and indicators, as well as an option for evaluating a sequence of trades, with ready-to-use implementations in MQL5.
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Motifs and Discords: Building a Matrix Profile from Scratch

Motifs and Discords: Building a Matrix Profile from Scratch

We build the Matrix Profile for MQL5 from the ground up and keep it numerically stable on real prices. The library includes rolling statistics, a radix-2 FFT powering MASS, and a STOMP self-join, with results matched to stumpy. A compact facade, an indicator that draws the profile and flags discords, and a demonstration Expert Advisor show how to read and use the signal in practice.
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Graph Theory: Study of Graphs Generated by Some Random Process

Graph Theory: Study of Graphs Generated by Some Random Process

This article describes an MQL5 Expert Advisor that models the market as a random graph rather than a fixed structure. Bars are encoded into discrete states; bar-to-bar moves form a decaying, Laplace-smoothed transition matrix, and a k-step random walk yields a bounded directional signal gated by an Erdos–Renyi null-model test. A separate trade-outcome graph over R-milestones learns survival probabilities to manage exits, turning position management into evidence-based rules.
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From Basic to Intermediate: Object Events (III)

From Basic to Intermediate: Object Events (III)

In this article, we will prepare the foundation for what will be covered in the next publication. We will also look at how to make an OBJ_LABEL object fully interactive for editing and moving. In other words, we can change both the text and the position of the OBJ_LABEL object without opening the Object Properties dialog.
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Beyond GARCH (Part VI): Fractional Brownian Motion And The Multiplicative Cascade in MQL5

Beyond GARCH (Part VI): Fractional Brownian Motion And The Multiplicative Cascade in MQL5

This article implements the MMAR Simulation Engine that turns fitted parameters (H, distribution, coefficients, sample volatility) into synthetic price paths. It builds multifractal trading time via a multiplicative cascade, synthesizes fractional Brownian motion with Davies–Harte or Cholesky, scales it to target volatility, and composes the process by time deformation. Readers get a reusable MQL5 class, method choices by path length, and validation steps for scenario testing and Monte Carlo use in the next part.
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From Basic to Intermediate: Classes (II)

From Basic to Intermediate: Classes (II)

This article is intended to be as educational as possible, since the topic we will be discussing often causes considerable confusion in itself. Therefore, dear reader, please try to put what is explained here into practice. If you have any questions, be sure to leave a comment—after all, understanding destructors is no easy task.
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Defining your Edge (Part 3): Using HMM and GRU in an Expert Advisor

Defining your Edge (Part 3): Using HMM and GRU in an Expert Advisor

We examine how a Hidden Markov Model (HMM) estimates latent market regimes while basing on observable price and indicator sequences. This is done by estimating the probability of state transitions. A Gated Recurrent Unit (GRU) network models time dependencies and keeps important information over several observations. In an Expert Advisor, HMM-based regime probabilities, can be merged with GRU-based sequence learning to better classify increments in accumulation, distribution, and momentum prior to their showing up in regular price confirmations.
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MetaTrader 5 as a Kafka Producer: Event-Bus Architecture for Multi-Terminal Signal Fan-Out

MetaTrader 5 as a Kafka Producer: Event-Bus Architecture for Multi-Terminal Signal Fan-Out

The article details a native MQL5 Kafka producer that speaks the wire protocol over raw TCP. It implements RecordBatch v2 encoding, varints, and CRC32C, and adds batching, acks, and retry logic, all without a sidecar or DLL. Use it to publish JSON-structured trading signals from a single terminal to Kafka, where dashboards and other services subscribe independently.
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Building a Prop-Firm Compliance Monitor in MQL5 (Part 1): Account Rules and Persistent Settings

Building a Prop-Firm Compliance Monitor in MQL5 (Part 1): Account Rules and Persistent Settings

Establishes the persistence foundation for a prop-firm compliance EA in MetaTrader 5. It introduces rule inputs and status enums, separates live account state from stored settings, validates percentages and thresholds, and implements SQLite open/close, schema creation, and prepared save/load operations. Using the account login and server as a composite key, the EA restores existing settings and updates them when inputs change.