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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Build Self Optimizing Expert Advisors in MQL5 (Part 5): Self Adapting Trading Rules

Build Self Optimizing Expert Advisors in MQL5 (Part 5): Self Adapting Trading Rules

The best practices, defining how to safely us an indicator, are not always easy to follow. Quiet market conditions may surprisingly produce readings on the indicator that do not qualify as a trading signal, leading to missed opportunities for algorithmic traders. This article will suggest a potential solution to this problem, as we discuss how to build trading applications capable of adapting their trading rules to the available market data.
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How to create a simple Multi-Currency Expert Advisor using MQL5 (Part 3): Added symbols prefixes and/or suffixes and Trading Time Session

How to create a simple Multi-Currency Expert Advisor using MQL5 (Part 3): Added symbols prefixes and/or suffixes and Trading Time Session

Several fellow traders sent emails or commented about how to use this Multi-Currency EA on brokers with symbol names that have prefixes and/or suffixes, and also how to implement trading time zones or trading time sessions on this Multi-Currency EA.
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How to create a simple Multi-Currency Expert Advisor using MQL5 (Part 7): ZigZag with Awesome Oscillator Indicators Signal

How to create a simple Multi-Currency Expert Advisor using MQL5 (Part 7): ZigZag with Awesome Oscillator Indicators Signal

The multi-currency expert advisor in this article is an expert advisor or automated trading that uses ZigZag indicator which are filtered with the Awesome Oscillator or filter each other's signals.
MQL4  as a Trader's Tool, or The Advanced Technical Analysis
MQL4  as a Trader's Tool, or The Advanced Technical Analysis

MQL4 as a Trader's Tool, or The Advanced Technical Analysis

Trading is, first of all, a calculus of probabilities. The proverb about idleness being an engine for progress reveals us the reason why all those indicators and trading systems have been developed. It comes that the major of newcomers in trading study "ready-made" trading theories. But, as luck would have it, there are some more undiscovered market secrets, and tools used in analyzing of price movements exist, basically, as those unrealized technical indicators or math and stat packages. Thanks awfully to Bill Williams for his contribution to the market movements theory. Though, perhaps, it's too early to rest on oars.
MT4TerminalSync - System for the Synchronization of MetaTrader 4 Terminals
MT4TerminalSync - System for the Synchronization of MetaTrader 4 Terminals

MT4TerminalSync - System for the Synchronization of MetaTrader 4 Terminals

This article is devoted to the topic "Widening possibilities of MQL4 programs by using functions of operating systems and other means of program development". The article describes an example of a program system that implements the task of the synchronization of several terminal copies based on a single source template.
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Neural Networks in Trading: A Multi-Agent System with Conceptual Reinforcement (FinCon)

Neural Networks in Trading: A Multi-Agent System with Conceptual Reinforcement (FinCon)

We invite you to explore the FinCon framework, which is a a Large Language Model (LLM)-based multi-agent system. The framework uses conceptual verbal reinforcement to improve decision making and risk management, enabling effective performance on a variety of financial tasks.
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Developing a trading Expert Advisor from scratch (Part 9): A conceptual leap (II)

Developing a trading Expert Advisor from scratch (Part 9): A conceptual leap (II)

In this article, we will place Chart Trade in a floating window. In the previous part, we created a basic system which enables the use of templates within a floating window.
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Ready-made templates for including indicators to Expert Advisors (Part 2): Volume and Bill Williams indicators

Ready-made templates for including indicators to Expert Advisors (Part 2): Volume and Bill Williams indicators

In this article, we will look at standard indicators of the Volume and Bill Williams' indicators category. We will create ready-to-use templates for indicator use in EAs - declaring and setting parameters, indicator initialization and deinitialization, as well as receiving data and signals from indicator buffers in EAs.
Beginners' Mistakes when Working with MetaTrader 4 Client Terminal
Beginners' Mistakes when Working with MetaTrader 4 Client Terminal

Beginners' Mistakes when Working with MetaTrader 4 Client Terminal

Err is human. Everybody makes mistakes: more or less frequently, through ignorance or inadvertently. You ask and we answer your questions about: terminal time, test results, Print in journal, symbols, history for Tester, history import, leverage, traffic, hints, scaling, wrong calculations, Invalid account, Empty News, Price changed, Not Enough Money, Market Is Closed.
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Developing a trading Expert Advisor from scratch (Part 13): Time and Trade (II)

Developing a trading Expert Advisor from scratch (Part 13): Time and Trade (II)

Today we will construct the second part of the Times & Trade system for market analysis. In the previous article "Times & Trade (I)" we discussed an alternative chart organization system, which would allow having an indicator for the quickest possible interpretation of deals executed in the market.
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USD and EUR index charts — example of a MetaTrader 5 service

USD and EUR index charts — example of a MetaTrader 5 service

We will consider the creation and updating of USD index (USDX) and EUR index (EURX) charts using a MetaTrader 5 service as an example. When launching the service, we will check for the presence of the required synthetic instrument, create it if necessary, and place it in the Market Watch window. The minute and tick history of the synthetic instrument is to be created afterwards followed by the chart of the created instrument.
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Neural networks made easy (Part 25): Practicing Transfer Learning

Neural networks made easy (Part 25): Practicing Transfer Learning

In the last two articles, we developed a tool for creating and editing neural network models. Now it is time to evaluate the potential use of Transfer Learning technology using practical examples.
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Building AI-Powered Trading Systems in MQL5 (Part 2): Developing a ChatGPT-Integrated Program with User Interface

Building AI-Powered Trading Systems in MQL5 (Part 2): Developing a ChatGPT-Integrated Program with User Interface

In this article, we develop a ChatGPT-integrated program in MQL5 with a user interface, leveraging the JSON parsing framework from Part 1 to send prompts to OpenAI’s API and display responses on a MetaTrader 5 chart. We implement a dashboard with an input field, submit button, and response display, handling API communication and text wrapping for user interaction.
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Price Action Analysis Toolkit Development (Part 42): Interactive Chart Testing with Button Logic and Statistical Levels

Price Action Analysis Toolkit Development (Part 42): Interactive Chart Testing with Button Logic and Statistical Levels

In a world where speed and precision matter, analysis tools need to be as smart as the markets we trade. This article presents an EA built on button logic—an interactive system that instantly transforms raw price data into meaningful statistical levels. With a single click, it calculates and displays mean, deviation, percentiles, and more, turning advanced analytics into clear on-chart signals. It highlights the zones where price is most likely to bounce, retrace, or break, making analysis both faster and more practical.
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MQL5 Cookbook — Macroeconomic events database

MQL5 Cookbook — Macroeconomic events database

The article discusses the possibilities of handling databases based on the SQLite engine. The CDatabase class has been formed for convenience and efficient use of OOP principles. It is subsequently involved in the creation and management of the database of macroeconomic events. The article provides the examples of using multiple methods of the CDatabase class.
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Neural Networks in Trading: Parameter-Efficient Transformer with Segmented Attention (Final Part)

Neural Networks in Trading: Parameter-Efficient Transformer with Segmented Attention (Final Part)

In the previous work, we discussed the theoretical aspects of the PSformer framework, which includes two major innovations in the classical Transformer architecture: the Parameter Shared (PS) mechanism and attention to spatio-temporal segments (SegAtt). In this article, we continue the work we started on implementing the proposed approaches using MQL5.
Timeseries in DoEasy library (part 48): Multi-period multi-symbol indicators on one buffer in a subwindow
Timeseries in DoEasy library (part 48): Multi-period multi-symbol indicators on one buffer in a subwindow

Timeseries in DoEasy library (part 48): Multi-period multi-symbol indicators on one buffer in a subwindow

The article considers an example of creating multi-symbol multi-period standard indicators using a single indicator buffer for construction and working in the indicator subwindow. I am going to prepare the library classes for working with standard indicators working in the program main window and having more than one buffer for displaying their data.
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Neural networks made easy (Part 76): Exploring diverse interaction patterns with Multi-future Transformer

Neural networks made easy (Part 76): Exploring diverse interaction patterns with Multi-future Transformer

This article continues the topic of predicting the upcoming price movement. I invite you to get acquainted with the Multi-future Transformer architecture. Its main idea is to decompose the multimodal distribution of the future into several unimodal distributions, which allows you to effectively simulate various models of interaction between agents on the scene.
The Random Sandbox
The Random Sandbox

The Random Sandbox

The article includes an interactive "sandbox" as an Excel file which simulates randomized Expert Advisor backtest data. Readers can use this to help explore and more deeply understand the EA performance metrics offered by default with MetaTrader. The text of the article is designed to guide the user through this experience.
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News Trading Made Easy (Part 1): Creating a Database

News Trading Made Easy (Part 1): Creating a Database

News trading can be complicated and overwhelming, in this article we will go through steps to obtain news data. Additionally we will learn about the MQL5 Economic Calendar and what it has to offer.
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DoEasy. Controls (Part 6): Panel control, auto resizing the container to fit inner content

DoEasy. Controls (Part 6): Panel control, auto resizing the container to fit inner content

In the article, I will continue my work on the Panel WinForms object and implement its auto resizing to fit the general size of Dock objects located inside the panel. Besides, I will add the new properties to the Symbol library object.
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Introduction to MQL5 (Part 19): Automating Wolfe Wave Detection

Introduction to MQL5 (Part 19): Automating Wolfe Wave Detection

This article shows how to programmatically identify bullish and bearish Wolfe Wave patterns and trade them using MQL5. We’ll explore how to identify Wolfe Wave structures programmatically and execute trades based on them using MQL5. This includes detecting key swing points, validating pattern rules, and preparing the EA to act on the signals it finds.
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Reimagining Classic Strategies (Part 15): Daily Breakout Trading Strategy

Reimagining Classic Strategies (Part 15): Daily Breakout Trading Strategy

Human traders had long participated in financial markets before the rise of computers, developing rules of thumb that guided their decisions. In this article, we revisit a well-known breakout strategy to test whether such market logic, learned through experience, can hold its own against systematic methods. Our findings show that while the original strategy produced high accuracy, it suffered from instability and poor risk control. By refining the approach, we demonstrate how discretionary insights can be adapted into more robust, algorithmic trading strategies.
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Introduction to MQL5 (Part 15): A Beginner's Guide to Building Custom Indicators (IV)

Introduction to MQL5 (Part 15): A Beginner's Guide to Building Custom Indicators (IV)

In this article, you'll learn how to build a price action indicator in MQL5, focusing on key points like low (L), high (H), higher low (HL), higher high (HH), lower low (LL), and lower high (LH) for analyzing trends. You'll also explore how to identify the premium and discount zones, mark the 50% retracement level, and use the risk-reward ratio to calculate profit targets. The article also covers determining entry points, stop loss (SL), and take profit (TP) levels based on the trend structure.
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How to build and optimize a volatility-based trading system (Chaikin Volatility - CHV)

How to build and optimize a volatility-based trading system (Chaikin Volatility - CHV)

In this article, we will provide another volatility-based indicator named Chaikin Volatility. We will understand how to build a custom indicator after identifying how it can be used and constructed. We will share some simple strategies that can be used and then test them to understand which one can be better.
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Introduction to MQL5 (Part 9): Understanding and Using Objects in MQL5

Introduction to MQL5 (Part 9): Understanding and Using Objects in MQL5

Learn to create and customize chart objects in MQL5 using current and historical data. This project-based guide helps you visualize trades and apply MQL5 concepts practically, making it easier to build tools tailored to your trading needs.
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Graph Theory: Dijkstra's Algorithm Applied in Trading

Graph Theory: Dijkstra's Algorithm Applied in Trading

Dijkstra's algorithm, a classic shortest-path solution in graph theory, can optimize trading strategies by modeling market networks. Traders can use it to find the most efficient routes in the candlestick chart data.
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Category Theory (Part 9): Monoid-Actions

Category Theory (Part 9): Monoid-Actions

This article continues the series on category theory implementation in MQL5. Here we continue monoid-actions as a means of transforming monoids, covered in the previous article, leading to increased applications.
Population optimization algorithms
Population optimization algorithms

Population optimization algorithms

This is an introductory article on optimization algorithm (OA) classification. The article attempts to create a test stand (a set of functions), which is to be used for comparing OAs and, perhaps, identifying the most universal algorithm out of all widely known ones.
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Developing a multi-currency Expert Advisor (Part 1): Collaboration of several trading strategies

Developing a multi-currency Expert Advisor (Part 1): Collaboration of several trading strategies

There are quite a lot of different trading strategies. So, it might be useful to apply several strategies working in parallel to diversify risks and increase the stability of trading results. But if each strategy is implemented as a separate Expert Advisor (EA), then managing their work on one trading account becomes much more difficult. To solve this problem, it would be reasonable to implement the operation of different trading strategies within a single EA.
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Build Self Optimizing Expert Advisors in MQL5  (Part 3): Dynamic Trend Following and Mean Reversion Strategies

Build Self Optimizing Expert Advisors in MQL5 (Part 3): Dynamic Trend Following and Mean Reversion Strategies

Financial markets are typically classified as either in a range mode or a trending mode. This static view of the market may make it easier for us to trade in the short run. However, it is disconnected from the reality of the market. In this article, we look to better understand how exactly financial markets move between these 2 possible modes and how we can use our new understanding of market behavior to gain confidence in our algorithmic trading strategies.
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MetaTrader 5 Machine Learning Blueprint (Part 1): Data Leakage and Timestamp Fixes

MetaTrader 5 Machine Learning Blueprint (Part 1): Data Leakage and Timestamp Fixes

Before we can even begin to make use of ML in our trading on MetaTrader 5, it’s crucial to address one of the most overlooked pitfalls—data leakage. This article unpacks how data leakage, particularly the MetaTrader 5 timestamp trap, can distort our model's performance and lead to unreliable trading signals. By diving into the mechanics of this issue and presenting strategies to prevent it, we pave the way for building robust machine learning models that deliver trustworthy predictions in live trading environments.
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Moving Average in MQL5 from scratch: Plain and simple

Moving Average in MQL5 from scratch: Plain and simple

Using simple examples, we will examine the principles of calculating moving averages, as well as learn about the ways to optimize indicator calculations, including moving averages.
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Econometric tools for forecasting volatility: GARCH model

Econometric tools for forecasting volatility: GARCH model

The article describes the properties of the non-linear model of conditional heteroscedasticity (GARCH). The iGARCH indicator has been built on its basis for predicting volatility one step ahead. The ALGLIB numerical analysis library is used to estimate the model parameters.
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Data Science and Machine Learning (Part 24): Forex Time series Forecasting Using Regular AI Models

Data Science and Machine Learning (Part 24): Forex Time series Forecasting Using Regular AI Models

In the forex markets It is very challenging to predict the future trend without having an idea of the past. Very few machine learning models are capable of making the future predictions by considering past values. In this article, we are going to discuss how we can use classical(Non-time series) Artificial Intelligence models to beat the market
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Price Action Analysis Toolkit Development (Part 17): TrendLoom EA Tool

Price Action Analysis Toolkit Development (Part 17): TrendLoom EA Tool

As a price action observer and trader, I've noticed that when a trend is confirmed by multiple timeframes, it usually continues in that direction. What may vary is how long the trend lasts, and this depends on the type of trader you are, whether you hold positions for the long term or engage in scalping. The timeframes you choose for confirmation play a crucial role. Check out this article for a quick, automated system that helps you analyze the overall trend across different timeframes with just a button click or regular updates.
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Introduction to MQL5 (Part 14): A Beginner's Guide to Building Custom Indicators (III)

Introduction to MQL5 (Part 14): A Beginner's Guide to Building Custom Indicators (III)

Learn to build a Harmonic Pattern indicator in MQL5 using chart objects. Discover how to detect swing points, apply Fibonacci retracements, and automate pattern recognition.
Interview with Enbo Lu (ATC 2012)
Interview with Enbo Lu (ATC 2012)

Interview with Enbo Lu (ATC 2012)

"Be sure to participate in the Automated Trading Championships, where you can get a truly invaluable experience!" - this is the motto of contestant Enbo Lu (luenbo) from China. He appeared in the TOP-10 of Automated Trading Championship 2012 last week and is now consistently trying to reach the podium.
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Revisiting Murray system

Revisiting Murray system

Graphical price analysis systems are deservedly popular among traders. In this article, I am going to describe the complete Murray system, including its famous levels, as well as some other useful techniques for assessing the current price position and making a trading decision.
Expert Advisors Based on Popular Trading Strategies and Alchemy of Trading Robot Optimization (Part VI)
Expert Advisors Based on Popular Trading Strategies and Alchemy of Trading Robot Optimization (Part VI)

Expert Advisors Based on Popular Trading Strategies and Alchemy of Trading Robot Optimization (Part VI)

In this article, the author proposes the way of improving trading systems presented in his previous articles. The article is of interest for traders already having experiences in writing Expert Advisors.