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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MQL5 Wizard Techniques you should know (Part 37): Gaussian Process Regression with Linear and Matérn Kernels

MQL5 Wizard Techniques you should know (Part 37): Gaussian Process Regression with Linear and Matérn Kernels

Linear Kernels are the simplest matrix of its kind used in machine learning for linear regression and support vector machines. The Matérn kernel on the other hand is a more versatile version of the Radial Basis Function we looked at in an earlier article, and it is adept at mapping functions that are not as smooth as the RBF would assume. We build a custom signal class that utilizes both kernels in forecasting long and short conditions.
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Developing a Replay System (Part 74): New Chart Trade (I)

Developing a Replay System (Part 74): New Chart Trade (I)

In this article, we will modify the last code shown in this series about Chart Trade. These changes are necessary to adapt the code to the current replay/simulation system model. The content presented here is intended solely for educational purposes. Under no circumstances should the application be viewed for any purpose other than to learn and master the concepts presented.
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Neural networks made easy (Part 68): Offline Preference-guided Policy Optimization

Neural networks made easy (Part 68): Offline Preference-guided Policy Optimization

Since the first articles devoted to reinforcement learning, we have in one way or another touched upon 2 problems: exploring the environment and determining the reward function. Recent articles have been devoted to the problem of exploration in offline learning. In this article, I would like to introduce you to an algorithm whose authors completely eliminated the reward function.
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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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Price Action Analysis Toolkit Development (Part 8): Metrics Board

Price Action Analysis Toolkit Development (Part 8): Metrics Board

As one of the most powerful Price Action analysis toolkits, the Metrics Board is designed to streamline market analysis by instantly providing essential market metrics with just a click of a button. Each button serves a specific function, whether it’s analyzing high/low trends, volume, or other key indicators. This tool delivers accurate, real-time data when you need it most. Let’s dive deeper into its features in this article.
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Turtle Shell Evolution Algorithm (TSEA)

Turtle Shell Evolution Algorithm (TSEA)

This is a unique optimization algorithm inspired by the evolution of the turtle shell. The TSEA algorithm emulates the gradual formation of keratinized skin areas, which represent optimal solutions to a problem. The best solutions become "harder" and are located closer to the outer surface, while the less successful solutions remain "softer" and are located inside. The algorithm uses clustering of solutions by quality and distance, allowing to preserve less successful options and providing flexibility and adaptability.
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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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Self Optimizing Expert Advisors in MQL5 (Part 16): Supervised Linear System Identification

Self Optimizing Expert Advisors in MQL5 (Part 16): Supervised Linear System Identification

Linear system identifcation may be coupled to learn to correct the error in a supervised learning algorithm. This allows us to build applications that depend on statistical modelling techniques without necessarily inheriting the fragility of the model's restrictive assumptions. Classical supervised learning algorithms have many needs that may be supplemented by pairing these models with a feedback controller that can correct the model to keep up with current market conditions.
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Formulating Dynamic Multi-Pair EA (Part 9): Market Microstructure Execution Noise Filtering

Formulating Dynamic Multi-Pair EA (Part 9): Market Microstructure Execution Noise Filtering

This article presents a multi-symbol execution filter that scores real-time market quality before any trade is allowed. It measures spread behavior, tick velocity, quote gaps, micro-volatility, and a slippage estimate, then classifies the state to block degraded conditions. Once noise settles, a liquidity sweep continuation model evaluates structure shifts so entries occur only when execution is mechanically stable.
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Functions for activating neurons during training: The key to fast convergence?

Functions for activating neurons during training: The key to fast convergence?

This article presents a study of the interaction of different activation functions with optimization algorithms in the context of neural network training. Particular attention is paid to the comparison of the classical ADAM and its population version when working with a wide range of activation functions, including the oscillating ACON and Snake functions. Using a minimalistic MLP (1-1-1) architecture and a single training example, the influence of activation functions on the optimization is isolated from other factors. The article proposes an approach to manage network weights through the boundaries of activation functions and a weight reflection mechanism, which allows avoiding problems with saturation and stagnation in training.
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Developing a multi-currency Expert Advisor (Part 6): Automating the selection of an instance group

Developing a multi-currency Expert Advisor (Part 6): Automating the selection of an instance group

After optimizing the trading strategy, we receive sets of parameters. We can use them to create several instances of trading strategies combined in one EA. Previously, we did this manually. Here we will try to automate this process.
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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.
Interview with Igor Korepin (ATC 2011)
Interview with Igor Korepin (ATC 2011)

Interview with Igor Korepin (ATC 2011)

Appearance of the Expert Advisor cs2011 by Igor Korepin (Xupypr) at the very top of the Automated Trading Championship 2011 was really impressive - its balance was almost twice that of the EA featured on the second place. However, despite such a sound breakaway, the Expert Advisor could not stay long on the first line. Igor frankly said that he relied much on a lucky start of his trading robot in the competition. We'll see if luck helps this simple EA to take the lead in the ATC 2011 race again.
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Neural Networks in Trading: Unified Trajectory Generation Model (UniTraj)

Neural Networks in Trading: Unified Trajectory Generation Model (UniTraj)

Understanding agent behavior is important in many different areas, but most methods focus on just one of the tasks (understanding, noise removal, or prediction), which reduces their effectiveness in real-world scenarios. In this article, we will get acquainted with a model that can adapt to solving various problems.
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Forex arbitrage trading: Analyzing synthetic currencies movements and their mean reversion

Forex arbitrage trading: Analyzing synthetic currencies movements and their mean reversion

In this article, we will examine the movements of synthetic currencies using Python and MQL5 and explore how feasible Forex arbitrage is today. We will also consider ready-made Python code for analyzing synthetic currencies and share more details on what synthetic currencies are in Forex.
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Reimagining Classic Strategies (Part V): Multiple Symbol Analysis on USDZAR

Reimagining Classic Strategies (Part V): Multiple Symbol Analysis on USDZAR

In this series of articles, we revisit classical strategies to see if we can improve the strategy using AI. In today's article, we will examine a popular strategy of multiple symbol analysis using a basket of correlated securities, we will focus on the exotic USDZAR currency pair.
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Archery Algorithm (AA)

Archery Algorithm (AA)

The article takes a detailed look at the archery-inspired optimization algorithm, with an emphasis on using the roulette method as a mechanism for selecting promising areas for "arrows". The method allows evaluating the quality of solutions and selecting the most promising positions for further study.
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Self Optimizing Expert Advisors in MQL5 (Part 8): Multiple Strategy Analysis (2)

Self Optimizing Expert Advisors in MQL5 (Part 8): Multiple Strategy Analysis (2)

Join us for our follow-up discussion, where we will merge our first two trading strategies into an ensemble trading strategy. We shall demonstrate the different schemes possible for combining multiple strategies and also how to exercise control over the parameter space, to ensure that effective optimization remains possible even as our parameter size grows.
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Neural Networks in Trading: Lightweight Models for Time Series Forecasting

Neural Networks in Trading: Lightweight Models for Time Series Forecasting

Lightweight time series forecasting models achieve high performance using a minimum number of parameters. This, in turn, reduces the consumption of computing resources and speeds up decision-making. Despite being lightweight, such models achieve forecast quality comparable to more complex ones.
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Building A Candlestick Trend Constraint Model (Part 4): Customizing Display Style For Each Trend Wave

Building A Candlestick Trend Constraint Model (Part 4): Customizing Display Style For Each Trend Wave

In this article, we will explore the capabilities of the powerful MQL5 language in drawing various indicator styles on Meta Trader 5. We will also look at scripts and how they can be used in our model.
Simultaneous Displaying of the Signals of Several Indicators from the Four Timeframes
Simultaneous Displaying of the Signals of Several Indicators from the Four Timeframes

Simultaneous Displaying of the Signals of Several Indicators from the Four Timeframes

While manual trading you have to keep an eye on the values of several indicators. It is a little bit different from mechanical trading. If you have two or three indicators and you have chosen a one timeframe for trading, it is not a complicated task. But what will you do if you have five or six indicators and your trading strategy requires considering the signals on the several timeframes?
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Category Theory in MQL5 (Part 18): Naturality Square

Category Theory in MQL5 (Part 18): Naturality Square

This article continues our series into category theory by introducing natural transformations, a key pillar within the subject. We look at the seemingly complex definition, then delve into examples and applications with this series’ ‘bread and butter’; volatility forecasting.
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Using the MQL5 Economic Calendar for News Filter (Part 4): Accurate Backtesting with Static Data

Using the MQL5 Economic Calendar for News Filter (Part 4): Accurate Backtesting with Static Data

This article implements a static, CSV-based news source for the Strategy Tester, so historical economic news events can be preloaded and queried during backtesting. It replaces live calendar calls in tester mode with a fast in-memory search, preserves the live logic for trading, and delivers deterministic, repeatable results with explicit control over included events, enabling reliable validation of news-aware filters, stop suspension, and trade-blocking rules.
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Artificial Atom Algorithm (A3)

Artificial Atom Algorithm (A3)

The article describes implementation of the A3 algorithm - a metaheuristic optimization method inspired by chemical processes - in MQL5. Only two adjustable parameters, compactness and a small population, ensure high operating speed with sufficient quality of solutions.
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Developing an MQL5 Reinforcement Learning agent with RestAPI integration (Part 1): How to use RestAPIs in MQL5

Developing an MQL5 Reinforcement Learning agent with RestAPI integration (Part 1): How to use RestAPIs in MQL5

In this article we will talk about the importance of APIs (Application Programming Interface) for interaction between different applications and software systems. We will see the role of APIs in simplifying interactions between applications, allowing them to efficiently share data and functionality.
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Python-MetaTrader 5 Strategy Tester (Part 02): Dealing with Bars, Ticks, and Overloading Built-in Functions in a Simulator

Python-MetaTrader 5 Strategy Tester (Part 02): Dealing with Bars, Ticks, and Overloading Built-in Functions in a Simulator

In this article, we introduce functions similar to those provided by the Python-MetaTrader 5 module, providing a simulator with a familiar interface and a custom way of handling bars and ticks internally.
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Data Science and Machine Learning (Part 20): Algorithmic Trading Insights, A Faceoff Between LDA and PCA in MQL5

Data Science and Machine Learning (Part 20): Algorithmic Trading Insights, A Faceoff Between LDA and PCA in MQL5

Uncover the secrets behind these powerful dimensionality reduction techniques as we dissect their applications within the MQL5 trading environment. Delve into the nuances of Linear Discriminant Analysis (LDA) and Principal Component Analysis (PCA), gaining a profound understanding of their impact on strategy development and market analysis.
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Design Patterns in software development and MQL5 (Part 2): Structural Patterns

Design Patterns in software development and MQL5 (Part 2): Structural Patterns

In this article, we will continue our articles about Design Patterns after learning how much this topic is more important for us as developers to develop extendable, reliable applications not only by the MQL5 programming language but others as well. We will learn about another type of Design Patterns which is the structural one to learn how to design systems by using what we have as classes to form larger structures.
Interview with Berron Parker (ATC 2010)
Interview with Berron Parker (ATC 2010)

Interview with Berron Parker (ATC 2010)

During the first week of the Championship Berron's Expert Advisor has been on the top position. He now tells us about his experience of EA development and difficulties of moving to MQL5. Berron says his EA is set up to work in a trend market, but can be weak in other market conditions. However, he is hopeful that his robot will show good results in this competition.
Idleness is the Stimulus to Progress. Semiautomatic Marking a Template
Idleness is the Stimulus to Progress. Semiautomatic Marking a Template

Idleness is the Stimulus to Progress. Semiautomatic Marking a Template

Among the dozens of examples of how to work with charts, there is a method of manual marking a template. Trend lines, channels, support/resistance levels, etc. are imposed in a chart. Surely, there are some special programs for this kind of work. Everyone decides on his/her own which method to use. In this article, I offer you for your consideration the methods of manual marking with subsequent automating some elements of the repeated routine actions.
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Market Reactions and Trading Strategies in Response to Dividend Announcements: Evaluating the Efficient Market Hypothesis in Stock Trading

Market Reactions and Trading Strategies in Response to Dividend Announcements: Evaluating the Efficient Market Hypothesis in Stock Trading

In this article, we will analyse the impact of dividend announcements on stock market returns and see how investors can earn more returns than those offered by the market when they expect a company to announce dividends. In doing so, we will also check the validity of the Efficient Market Hypothesis in the context of the Indian Stock Market.
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MQL5 Wizard Techniques you should know (Part 57): Supervised Learning with Moving Average and Stochastic Oscillator

MQL5 Wizard Techniques you should know (Part 57): Supervised Learning with Moving Average and Stochastic Oscillator

Moving Average and Stochastic Oscillator are very common indicators that some traders may not use a lot because of their lagging nature. In a 3-part ‘miniseries' that considers the 3 main forms of machine learning, we look to see if this bias against these indicators is justified, or they might be holding an edge. We do our examination in wizard assembled Expert Advisors.
Interview with Andrey Bobryashov (ATC 2011)
Interview with Andrey Bobryashov (ATC 2011)

Interview with Andrey Bobryashov (ATC 2011)

Since the first Automated Trading Championship we have seen plenty of trading robots in our TOP-10 created with the use of various methods. Excellent results were shown both by the Exper Advisors based on standard indicators, and complicated analytical complexes with weekly automatic optimization of their own parameters.
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Category Theory in MQL5 (Part 7): Multi, Relative and Indexed Domains

Category Theory in MQL5 (Part 7): Multi, Relative and Indexed Domains

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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DoEasy. Controls (Part 12): Base list object, ListBox and ButtonListBox WinForms objects

DoEasy. Controls (Part 12): Base list object, ListBox and ButtonListBox WinForms objects

In this article, I am going to create the base object of WinForms object lists, as well as the two new objects: ListBox and ButtonListBox.
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Creating a Custom Tick Chart in MQL5

Creating a Custom Tick Chart in MQL5

Learn how to implement a tick-based chart in MQL5 where each bar is built from a fixed number of ticks instead of time. The article covers creating and configuring a custom symbol, capturing real-time ticks, forming OHLC values, and pushing data with CustomRatesUpdate. This approach produces activity-driven candles that better reflect market intensity and short-term momentum for precise intraday analysis.
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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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Creating a Trading Administrator Panel in MQL5 (Part II): Enhancing Responsiveness and Quick Messaging

Creating a Trading Administrator Panel in MQL5 (Part II): Enhancing Responsiveness and Quick Messaging

In this article, we will enhance the responsiveness of the Admin Panel that we previously created. Additionally, we will explore the significance of quick messaging in the context of trading signals.
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Fibonacci in Forex (Part I): Examining the Price-Time Relationship

Fibonacci in Forex (Part I): Examining the Price-Time Relationship

How does the market observe Fibonacci-based relationships? This sequence, where each subsequent number is equal to the sum of the two previous ones (1, 1, 2, 3, 5, 8, 13, 21...), not only describes the growth of the rabbit population. We will consider the Pythagorean hypothesis that everything in the world is subject to certain relationships of numbers...
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Neural networks made easy (Part 46): Goal-conditioned reinforcement learning (GCRL)

Neural networks made easy (Part 46): Goal-conditioned reinforcement learning (GCRL)

In this article, we will have a look at yet another reinforcement learning approach. It is called goal-conditioned reinforcement learning (GCRL). In this approach, an agent is trained to achieve different goals in specific scenarios.