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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Interview with Andrei Moraru (ATC 2011)
Interview with Andrei Moraru (ATC 2011)

Interview with Andrei Moraru (ATC 2011)

Ukrainian programmer Andrei Moraru (enivid) is an active participant of the Automated Trading Championship beginning from 2007. Andrei had already come in our view at that time and now we have decided to find out if there occured any changes in his attitude towards trading and selection of trading strategies for the past four years, and also to know about his new Expert Advisor.
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Neural networks made easy (Part 78): Decoder-free Object Detector with Transformer (DFFT)

Neural networks made easy (Part 78): Decoder-free Object Detector with Transformer (DFFT)

In this article, I propose to look at the issue of building a trading strategy from a different angle. We will not predict future price movements, but will try to build a trading system based on the analysis of historical data.
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From Novice to Expert: Animated News Headline Using MQL5 (X)—Multiple Symbol Chart View for News Trading

From Novice to Expert: Animated News Headline Using MQL5 (X)—Multiple Symbol Chart View for News Trading

Today we will develop a multi-chart view system using chart objects. The goal is to enhance news trading by applying MQL5 algorithms that help reduce trader reaction time during periods of high volatility, such as major news releases. In this case, we provide traders with an integrated way to monitor multiple major symbols within a single all-in-one news trading tool. Our work is continuously advancing with the News Headline EA, which now features a growing set of functions that add real value both for traders using fully automated systems and for those who prefer manual trading assisted by algorithms. Explore more knowledge, insights, and practical ideas by clicking through and joining this discussion.
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Neural Network in Practice: The First Neuron

Neural Network in Practice: The First Neuron

In this article, we'll start building something simple and humble: a neuron. We will program it with a very small amount of MQL5 code. The neuron worked great in my tests. Let's go back a bit in this series of articles about neural networks to understand what I'm talking about.
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Developing a multi-currency Expert Advisor (Part 8): Load testing and handling a new bar

Developing a multi-currency Expert Advisor (Part 8): Load testing and handling a new bar

As we progressed, we used more and more simultaneously running instances of trading strategies in one EA. Let's try to figure out how many instances we can get to before we hit resource limitations.
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Risk-Based Trade Placement EA with On-Chart UI (Part 1): Designing the User Interface

Risk-Based Trade Placement EA with On-Chart UI (Part 1): Designing the User Interface

Learn how to build a clean and professional on-chart control panel in MQL5 for a Risk-Based Trade Placement Expert Advisor. This step-by-step guide explains how to design a functional GUI that allows traders to input trade parameters, calculate lot size, and prepare for automated order placement.
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Python-MetaTrader 5 Strategy Tester (Part 03): MetaTrader 5-Like Trading Operations — Handling and Managing

Python-MetaTrader 5 Strategy Tester (Part 03): MetaTrader 5-Like Trading Operations — Handling and Managing

In this article we introduce Python-MetaTrader5-like ways of handling trading operations such as opening, closing, and modifying orders in the simulator. To ensure the simulation behaves like MetaTrader 5, a strict validation layer for trade requests is implemented, taking into account symbol trading parameters and typical brokerage restrictions.
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Developing a multi-currency Expert Advisor (Part 15): Preparing EA for real trading

Developing a multi-currency Expert Advisor (Part 15): Preparing EA for real trading

As we gradually approach to obtaining a ready-made EA, we need to pay attention to issues that seem secondary at the stage of testing a trading strategy, but become important when moving on to real trading.
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Population ADAM (Adaptive Moment Estimation)

Population ADAM (Adaptive Moment Estimation)

The article presents the transformation of the well-known and popular ADAM gradient optimization method into a population algorithm and its modification with the introduction of hybrid individuals. The new approach allows creating agents that combine elements of successful decisions using probability distribution. The key innovation is the formation of hybrid population individuals that adaptively accumulate information from the most promising solutions, increasing the efficiency of search in complex multidimensional spaces.
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Category Theory in MQL5 (Part 5): Equalizers

Category Theory in MQL5 (Part 5): Equalizers

Category Theory is a diverse and expanding branch of Mathematics which is only recently getting some coverage in the MQL5 community. These series of articles look to explore and examine some of its concepts & axioms with the overall goal of establishing an open library that provides insight while also hopefully furthering the use of this remarkable field in Traders' strategy development.
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Developing a Replay System — Market simulation (Part 11): Birth of the SIMULATOR (I)

Developing a Replay System — Market simulation (Part 11): Birth of the SIMULATOR (I)

In order to use the data that forms the bars, we must abandon replay and start developing a simulator. We will use 1 minute bars because they offer the least amount of difficulty.
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Developing a multi-currency Expert Advisor (Part 16): Impact of different quote histories on test results

Developing a multi-currency Expert Advisor (Part 16): Impact of different quote histories on test results

The EA under development is expected to show good results when trading with different brokers. But for now we have been using quotes from a MetaQuotes demo account to perform tests. Let's see if our EA is ready to work on a trading account with different quotes compared to those used during testing and optimization.
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Neural networks made easy (Part 45): Training state exploration skills

Neural networks made easy (Part 45): Training state exploration skills

Training useful skills without an explicit reward function is one of the main challenges in hierarchical reinforcement learning. Previously, we already got acquainted with two algorithms for solving this problem. But the question of the completeness of environmental research remains open. This article demonstrates a different approach to skill training, the use of which directly depends on the current state of the system.
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MQL5 Trading Tools (Part 5): Creating a Rolling Ticker Tape for Real-Time Symbol Monitoring

MQL5 Trading Tools (Part 5): Creating a Rolling Ticker Tape for Real-Time Symbol Monitoring

In this article, we develop a rolling ticker tape in MQL5 for real-time monitoring of multiple symbols, displaying bid prices, spreads, and daily percentage changes with scrolling effects. We implement customizable fonts, colors, and scroll speeds to highlight price movements and trends effectively.
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Category Theory in MQL5 (Part 22): A different look at Moving Averages

Category Theory in MQL5 (Part 22): A different look at Moving Averages

In this article we attempt to simplify our illustration of concepts covered in these series by dwelling on just one indicator, the most common and probably the easiest to understand. The moving average. In doing so we consider significance and possible applications of vertical natural transformations.
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Atomic Orbital Search (AOS) algorithm

Atomic Orbital Search (AOS) algorithm

The article considers the Atomic Orbital Search (AOS) algorithm, which uses the concepts of the atomic orbital model to simulate the search for solutions. The algorithm is based on probability distributions and the dynamics of interactions in the atom. The article discusses in detail the mathematical aspects of AOS, including updating the positions of candidate solutions and the mechanisms of energy absorption and release. AOS opens new horizons for applying quantum principles to computing problems by offering an innovative approach to optimization.
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From Novice to Expert: Animated News Headline Using MQL5 (III) — Indicator Insights

From Novice to Expert: Animated News Headline Using MQL5 (III) — Indicator Insights

In this article, we’ll advance the News Headline EA by introducing a dedicated indicator insights lane—a compact, on-chart display of key technical signals generated from popular indicators such as RSI, MACD, Stochastic, and CCI. This approach eliminates the need for multiple indicator subwindows on the MetaTrader 5 terminal, keeping your workspace clean and efficient. By leveraging the MQL5 API to access indicator data in the background, we can process and visualize market insights in real-time using custom logic. Join us as we explore how to manipulate indicator data in MQL5 to create an intelligent and space-saving scrolling insights system, all within a single horizontal lane on your trading chart.
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Adaptive Malaysian Engulfing Indicator (Part 2): Optimized Retest Bar Range

Adaptive Malaysian Engulfing Indicator (Part 2): Optimized Retest Bar Range

The article adds a self-adaptive layer to the Malaysian Engulfing indicator by optimizing the retest bar range with a constrained brute-force search scored by MFE and MAE. It details the data model, helper routines, and an MQL5 implementation that gathers historical setups, computes excursions, and selects the best parameter. Readers learn how to remove manual tuning and run the indicator with context-appropriate settings across symbols and timeframes.
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Quantitative approach to risk management: Applying VaR model to optimize multi-currency portfolio using Python and MetaTrader 5

Quantitative approach to risk management: Applying VaR model to optimize multi-currency portfolio using Python and MetaTrader 5

This article explores the potential of the Value at Risk (VaR) model for multi-currency portfolio optimization. Using the power of Python and the functionality of MetaTrader 5, we demonstrate how to implement VaR analysis for efficient capital allocation and position management. From theoretical foundations to practical implementation, the article covers all aspects of applying one of the most robust risk calculation systems – VaR – in algorithmic trading.
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Build Self Optimizing Expert Advisors in MQL5 (Part 7): Trading With Multiple Periods At Once

Build Self Optimizing Expert Advisors in MQL5 (Part 7): Trading With Multiple Periods At Once

In this series of articles, we have considered multiple different ways of identifying the best period to use our technical indicators with. Today, we shall demonstrate to the reader how they can instead perform the opposite logic, that is to say, instead of picking the single best period to use, we will demonstrate to the reader how to employ all available periods effectively. This approach reduces the amount of data discarded, and offers alternative use cases for machine learning algorithms beyond ordinary price prediction.
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DoEasy. Service functions (Part 3): Outside Bar pattern

DoEasy. Service functions (Part 3): Outside Bar pattern

In this article, we will develop the Outside Bar Price Action pattern in the DoEasy library and optimize the methods of access to price pattern management. In addition, we will fix errors and shortcomings identified during library tests.
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MQL5 Trading Tools (Part 32): Crosshair, Magnifier, and Measure Mode

MQL5 Trading Tools (Part 32): Crosshair, Magnifier, and Measure Mode

In this article, we extend the Tools Palette with a precision crosshair for MQL5 charts: reticle tick marks, full-width and full-height lines with axis labels, and a circular magnifier that renders zoomed candles. A double-click measure mode adds anchor markers, a diagonal connector, and a floating label with bars, pips, and price difference. Implementation details include a crosshair manager, eleven canvas layers, Bresenham line drawing, and theme-aware behavior that hides near the sidebar and fly out.
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Developing a Replay System — Market simulation (Part 14): Birth of the SIMULATOR (IV)

Developing a Replay System — Market simulation (Part 14): Birth of the SIMULATOR (IV)

In this article we will continue the simulator development stage. this time we will see how to effectively create a RANDOM WALK type movement. This type of movement is very intriguing because it forms the basis of everything that happens in the capital market. In addition, we will begin to understand some concepts that are fundamental to those conducting market analysis.
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MQL5 Wizard Techniques you should know (Part 26): Moving Averages and the Hurst Exponent

MQL5 Wizard Techniques you should know (Part 26): Moving Averages and the Hurst Exponent

The Hurst Exponent is a measure of how much a time series auto-correlates over the long term. It is understood to be capturing the long-term properties of a time series and therefore carries some weight in time series analysis even outside of economic/ financial time series. We however, focus on its potential benefit to traders by examining how this metric could be paired with moving averages to build a potentially robust signal.
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CSV Data Analysis (Part 4): Building an Automated Python-Driven Comparative Analysis Module for MQL5 Strategy Validation

CSV Data Analysis (Part 4): Building an Automated Python-Driven Comparative Analysis Module for MQL5 Strategy Validation

The article presents a reproducible MetaTrader 5 to Python pipeline for large-scale indicator research. An MQL5 export schema captures fixed columns, including custom lag and whipsaw counters. A baseline module performs parameter-matched comparisons across symbols and timeframes, while a walk-forward module locks the InSample optimum and evaluates it on unseen data. Readers gain unbiased robustness measurements and automation that removes manual selection bias.
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Neural Networks in Trading: Contrastive Pattern Transformer

Neural Networks in Trading: Contrastive Pattern Transformer

The Contrastive Transformer is designed to analyze markets both at the level of individual candlesticks and based on entire patterns. This helps improve the quality of market trend modeling. Moreover, the use of contrastive learning to align representations of candlesticks and patterns fosters self-regulation and improves the accuracy of forecasts.
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Building an EquiVolume Indicator in MQL5

Building an EquiVolume Indicator in MQL5

We implement an EquiVolume indicator in MQL5 that converts standard candlesticks into volume-weighted boxes. The workflow includes selecting volume type, detecting the maximum volume within a lookback range, normalizing all values against it, and mapping them into proportional box widths. The result is a chart-based structure that visualizes trading activity intensity alongside price movement in MetaTrader 5.
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Neural Networks in Trading: Controlled Segmentation (Final Part)

Neural Networks in Trading: Controlled Segmentation (Final Part)

We continue the work started in the previous article on building the RefMask3D framework using MQL5. This framework is designed to comprehensively study multimodal interaction and feature analysis in a point cloud, followed by target object identification based on a description provided in natural language.
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Sigma Score Indicator for MetaTrader 5: A Simple Statistical Anomaly Detector

Sigma Score Indicator for MetaTrader 5: A Simple Statistical Anomaly Detector

Build a practical MetaTrader 5 “Sigma Score” indicator from scratch and learn what it really measures: The z-score of log returns (how many standard deviations the latest move is from the recent average). The article walks through every code block in OnInit(), OnCalculate(), and OnDeinit(), then shows how to interpret thresholds (e.g., ±2) and apply the Sigma Score as a simple “market stress meter” for mean-reversion and momentum trading.
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Cross-validation and basics of causal inference in CatBoost models, export to ONNX format

Cross-validation and basics of causal inference in CatBoost models, export to ONNX format

The article proposes the method of creating bots using machine learning.
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Neural networks made easy (Part 51): Behavior-Guided Actor-Critic (BAC)

Neural networks made easy (Part 51): Behavior-Guided Actor-Critic (BAC)

The last two articles considered the Soft Actor-Critic algorithm, which incorporates entropy regularization into the reward function. This approach balances environmental exploration and model exploitation, but it is only applicable to stochastic models. The current article proposes an alternative approach that is applicable to both stochastic and deterministic models.
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From Novice to Expert: Backend Operations Monitor using MQL5

From Novice to Expert: Backend Operations Monitor using MQL5

Using a ready-made solution in trading without concerning yourself with the internal workings of the system may sound comforting, but this is not always the case for developers. Eventually, an upgrade, misperformance, or unexpected error will arise, and it becomes essential to trace exactly where the issue originates to diagnose and resolve it quickly. Today’s discussion focuses on uncovering what normally happens behind the scenes of a trading Expert Advisor, and on developing a custom dedicated class for displaying and logging backend processes using MQL5. This gives both developers and traders the ability to quickly locate errors, monitor behavior, and access diagnostic information specific to each EA.
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MetaTrader 5: Build a Market to Suit Your Strategy — Renko/Range/Volume, Synthetics, and Stress Tests on Custom Symbols

MetaTrader 5: Build a Market to Suit Your Strategy — Renko/Range/Volume, Synthetics, and Stress Tests on Custom Symbols

In this article, we demonstrate how to use API of the MetaTrader 5 custom symbols to transform your terminal into a data constructor for generating timeless Renko, Range, and Equal-Volume charts and assembling synthetic instruments. We will analyze tick aggregation and history modification for stress tests (spread widening, stop level changes) taking into account platform limitations. Besides, you will get some practice of handling CiCustomSymbol and routing orders to a real symbol through the CustomOrder wrapper with ready-made code fragments.
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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.
Developing a Replay System — Market simulation (Part 10): Using only real data for Replay
Developing a Replay System — Market simulation (Part 10): Using only real data for Replay

Developing a Replay System — Market simulation (Part 10): Using only real data for Replay

Here we will look at how we can use more reliable data (traded ticks) in the replay system without worrying about whether it is adjusted or not.
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Stress Testing Trade Sequences with Monte Carlo in MQL5

Stress Testing Trade Sequences with Monte Carlo in MQL5

A backtest shows only one path among many possible outcomes. This MQL5 script performs 1000 bootstrap Monte Carlo resamples of a trade P&L series, draws a percentile fan chart on the chart via CCanvas, and reports probability of ruin, value at risk, and 95th‑percentile worst drawdown. The result is a practical view of path risk and drawdown exposure beyond a single equity curve.
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Tracking Account Dynamics: Balance, Equity, and Floating P/L Visualization in MQL5

Tracking Account Dynamics: Balance, Equity, and Floating P/L Visualization in MQL5

Create a custom MT5 indicator that processes the entire deal history and plots starting balance, balance, equity, and floating P/L as continuous curves. It updates per bar, aggregates positions across symbols, and avoids external dependencies through local caching. Use it to inspect equity–balance divergence, realized vs. unrealized results, and the timing of risk deployment.
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Elements of correlation analysis in MQL5: Pearson chi-square test of independence and correlation ratio

Elements of correlation analysis in MQL5: Pearson chi-square test of independence and correlation ratio

The article observes classical tools of correlation analysis. An emphasis is made on brief theoretical background, as well as on the practical implementation of the Pearson chi-square test of independence and the correlation ratio.
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Triangular and Sawtooth Waves: Analytical Tools for Traders

Triangular and Sawtooth Waves: Analytical Tools for Traders

Wave analysis is one of the methods used in technical analysis. This article focuses on two less conventional wave patterns: triangular and sawtooth waves. These formations underpin a number of technical indicators designed for market price analysis.
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Self Optimizing Expert Advisors in MQL5 (Part 13): A Gentle Introduction To Control Theory Using Matrix Factorization

Self Optimizing Expert Advisors in MQL5 (Part 13): A Gentle Introduction To Control Theory Using Matrix Factorization

Financial markets are unpredictable, and trading strategies that look profitable in the past often collapse in real market conditions. This happens because most strategies are fixed once deployed and cannot adapt or learn from their mistakes. By borrowing ideas from control theory, we can use feedback controllers to observe how our strategies interact with markets and adjust their behavior toward profitability. Our results show that adding a feedback controller to a simple moving average strategy improved profits, reduced risk, and increased efficiency, proving that this approach has strong potential for trading applications.