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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Chart Synchronization for Easier Technical Analysis

Chart Synchronization for Easier Technical Analysis

Chart Synchronization for Easier Technical Analysis is a tool that ensures all chart timeframes display consistent graphical objects like trendlines, rectangles, or indicators across different timeframes for a single symbol. Actions such as panning, zooming, or symbol changes are mirrored across all synced charts, allowing traders to seamlessly view and compare the same price action context in multiple timeframes.
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Сode Lock Algorithm (CLA)

Сode Lock Algorithm (CLA)

In this article, we will rethink code locks, transforming them from security mechanisms into tools for solving complex optimization problems. Discover the world of code locks viewed not as simple security devices, but as inspiration for a new approach to optimization. We will create a whole population of "locks", where each lock represents a unique solution to the problem. We will then develop an algorithm that will "pick" these locks and find optimal solutions in a variety of areas, from machine learning to trading systems development.
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Building AI-Powered Trading Systems in MQL5 (Part 9): Creating an AI Signal Dispatcher

Building AI-Powered Trading Systems in MQL5 (Part 9): Creating an AI Signal Dispatcher

We turn the MQL5 AI trading assistant into a dispatch-driven system that routes seven trading actions through a single central dispatcher. A line-based key-value protocol constrains AI output, while each action maps to market or pending orders and instrument-aware stop levels. A canvas-based UI with a custom prompt editor and pixel-accurate text fitting makes signals consistent, auditable, and ready to render on the chart
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Data Science and Machine Learning (Part 13): Improve your financial market analysis with Principal Component Analysis (PCA)

Data Science and Machine Learning (Part 13): Improve your financial market analysis with Principal Component Analysis (PCA)

Revolutionize your financial market analysis with Principal Component Analysis (PCA)! Discover how this powerful technique can unlock hidden patterns in your data, uncover latent market trends, and optimize your investment strategies. In this article, we explore how PCA can provide a new lens for analyzing complex financial data, revealing insights that would be missed by traditional approaches. Find out how applying PCA to financial market data can give you a competitive edge and help you stay ahead of the curve
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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.
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Graphics in DoEasy library (Part 100): Making improvements in handling extended standard graphical objects

Graphics in DoEasy library (Part 100): Making improvements in handling extended standard graphical objects

In the current article, I will eliminate obvious flaws in simultaneous handling of extended (and standard) graphical objects and form objects on canvas, as well as fix errors detected during the test performed in the previous article. The article concludes this section of the library description.
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Formulating Dynamic Multi-Pair EA (Part 1): Currency Correlation and Inverse Correlation

Formulating Dynamic Multi-Pair EA (Part 1): Currency Correlation and Inverse Correlation

Dynamic multi pair Expert Advisor leverages both on correlation and inverse correlation strategies to optimize trading performance. By analyzing real-time market data, it identifies and exploits the relationship between currency pairs.
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Larry Williams Market Secrets (Part 13): Automating Hidden Smash Day Reversal Patterns

Larry Williams Market Secrets (Part 13): Automating Hidden Smash Day Reversal Patterns

The article builds a transparent MQL5 Expert Advisor for Larry Williams’ hidden smash day reversals. Signals are generated only on new bars: a setup bar is validated, then confirmed when the next session trades beyond its extreme. Risk is managed via ATR or structural stops with a defined risk-to-reward, position sizing can be fixed or balance-based, and direction filters plus a one-position policy ensure reproducible tests.
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MQL5 Wizard Techniques you should know (Part 09): Pairing K-Means Clustering with Fractal Waves

MQL5 Wizard Techniques you should know (Part 09): Pairing K-Means Clustering with Fractal Waves

K-Means clustering takes the approach to grouping data points as a process that’s initially focused on the macro view of a data set that uses random generated cluster centroids before zooming in and adjusting these centroids to accurately represent the data set. We will look at this and exploit a few of its use cases.
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MQL5 Wizard Techniques you should know (Part 44): Average True Range (ATR) technical indicator

MQL5 Wizard Techniques you should know (Part 44): Average True Range (ATR) technical indicator

The ATR oscillator is a very popular indicator for acting as a volatility proxy, especially in the forex markets where volume data is scarce. We examine this, on a pattern basis as we have with prior indicators, and share strategies & test reports thanks to the MQL5 wizard library classes and assembly.
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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Population optimization algorithms: Gravitational Search Algorithm (GSA)

Population optimization algorithms: Gravitational Search Algorithm (GSA)

GSA is a population optimization algorithm inspired by inanimate nature. Thanks to Newton's law of gravity implemented in the algorithm, the high reliability of modeling the interaction of physical bodies allows us to observe the enchanting dance of planetary systems and galactic clusters. In this article, I will consider one of the most interesting and original optimization algorithms. The simulator of the space objects movement is provided as well.
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Data Science and ML (Part 41): Forex and Stock Markets Pattern Detection using YOLOv8

Data Science and ML (Part 41): Forex and Stock Markets Pattern Detection using YOLOv8

Detecting patterns in financial markets is challenging because it involves seeing what's on the chart, something that's difficult to undertake in MQL5 due to image limitations. In this article, we are going to discuss a decent model made in Python that helps us detect patterns present on the chart with minimal effort.
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Integrating Hidden Markov Models in MetaTrader 5

Integrating Hidden Markov Models in MetaTrader 5

In this article we demonstrate how Hidden Markov Models trained using Python can be integrated into MetaTrader 5 applications. Hidden Markov Models are a powerful statistical tool used for modeling time series data, where the system being modeled is characterized by unobservable (hidden) states. A fundamental premise of HMMs is that the probability of being in a given state at a particular time depends on the process's state at the previous time slot.
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Creating an EA that works automatically (Part 10): Automation (II)

Creating an EA that works automatically (Part 10): Automation (II)

Automation means nothing if you cannot control its schedule. No worker can be efficient working 24 hours a day. However, many believe that an automated system should operate 24 hours a day. But it is always good to have means to set a working time range for the EA. In this article, we will consider how to properly set such a time range.
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Adaptive Malaysian Engulfing Indicator (Part 1): Pattern Detection and Retest Validation

Adaptive Malaysian Engulfing Indicator (Part 1): Pattern Detection and Retest Validation

Implement the Malaysian Engulfing concept in MQL5 with two coordinated indicators. One applies strict, body‑based engulfing rules for precise pattern detection; the other uses a state-driven model to monitor what follows—pullbacks and timed retests—directly on the chart. The result is a repeatable, rule-based workflow that replaces visual guesswork with programmable logic.
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Neural networks made easy (Part 49): Soft Actor-Critic

Neural networks made easy (Part 49): Soft Actor-Critic

We continue our discussion of reinforcement learning algorithms for solving continuous action space problems. In this article, I will present the Soft Actor-Critic (SAC) algorithm. The main advantage of SAC is the ability to find optimal policies that not only maximize the expected reward, but also have maximum entropy (diversity) of actions.
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Robustness Testing on Expert Advisors

Robustness Testing on Expert Advisors

In strategy development, there are many intricate details to consider, many of which are not highlighted for beginner traders. As a result, many traders, myself included, have had to learn these lessons the hard way. This article is based on my observations of common pitfalls that most beginner traders encounter when developing strategies on MQL5. It will offer a range of tips, tricks, and examples to help identify the disqualification of an EA and test the robustness of our own EAs in an easy-to-implement way. The goal is to educate readers, helping them avoid future scams when purchasing EAs as well as preventing mistakes in their own strategy development.
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Implementing the Janus factor in MQL5

Implementing the Janus factor in MQL5

Gary Anderson developed a method of market analysis based on a theory he dubbed the Janus Factor. The theory describes a set of indicators that can be used to reveal trends and assess market risk. In this article we will implement these tools in mql5.
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Developing a Custom Market Sentiment Indicator

Developing a Custom Market Sentiment Indicator

In this article we are developing a custom market sentiment indicator to classify conditions into bullish, bearish, risk-on, risk-off, or neutral. Using multi-timeframe, the indicator can provide traders with a clearer perspective of overall market bias and short-term confirmations.
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Price Action Analysis Toolkit Development (Part 75): Building a Modular Multi-Symbol Trading Panel in MQL5

Price Action Analysis Toolkit Development (Part 75): Building a Modular Multi-Symbol Trading Panel in MQL5

A structured MQL5 implementation of a multi‑symbol trading panel with clear separation of concerns: symbol handling, trading logic, and GUI. Integrated into an Expert Advisor, it validates symbols, exposes centralized controls for opening and positions managing across symbols, and applies SL/TP changes. Real‑time account and portfolio metrics help streamline routine operations from a single chart.
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Graph Theory: Heuristic Search Algorithm (A-Star) Applied in Trading

Graph Theory: Heuristic Search Algorithm (A-Star) Applied in Trading

The article applies the A* heuristic to market structure by modeling validated swing highs and lows as graph nodes and weighting edges with ATR‑normalized distance, spread, and noise penalties. The engine searches the most efficient route to infer trade direction and targets, then filters signals by directional ratio, total path cost, and opposing swings. It anchors TP to the final node and SL to prior structure, with on‑chart visualization and configurable inputs.
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Creating a Trading Administrator Panel in MQL5 (Part I): Building a Messaging Interface

Creating a Trading Administrator Panel in MQL5 (Part I): Building a Messaging Interface

This article discusses the creation of a Messaging Interface for MetaTrader 5, aimed at System Administrators, to facilitate communication with other traders directly within the platform. Recent integrations of social platforms with MQL5 allow for quick signal broadcasting across different channels. Imagine being able to validate sent signals with just a click—either "YES" or "NO." Read on to learn more.
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Continuous walk-forward optimization (Part 8): Program improvements and fixes

Continuous walk-forward optimization (Part 8): Program improvements and fixes

The program has been modified based on comments and requests from users and readers of this article series. This article contains a new version of the auto optimizer. This version implements requested features and provides other improvements, which I found when working with the program.
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Data Science and Machine Learning (Part 21): Unlocking Neural Networks, Optimization algorithms demystified

Data Science and Machine Learning (Part 21): Unlocking Neural Networks, Optimization algorithms demystified

Dive into the heart of neural networks as we demystify the optimization algorithms used inside the neural network. In this article, discover the key techniques that unlock the full potential of neural networks, propelling your models to new heights of accuracy and efficiency.
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Developing a trading Expert Advisor from scratch (Part 11): Cross order system

Developing a trading Expert Advisor from scratch (Part 11): Cross order system

In this article we will create a system of cross orders. There is one type of assets that makes traders' life very difficult for traders — futures contracts. But why do they make life difficult?
Interview with Sergey Abramov (ATC 2012)
Interview with Sergey Abramov (ATC 2012)

Interview with Sergey Abramov (ATC 2012)

The trading robot of Sergey Abramov (26405) is staying in TOP-10 since the second week. However, it caused much anxiety for its developer. As it turned out, the robot contains a small error in position close block. The robot has been developed almost exclusively on the basis of the past years' results.
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Introduction to MQL5 (Part 29): Mastering API and WebRequest Function in MQL5 (III)

Introduction to MQL5 (Part 29): Mastering API and WebRequest Function in MQL5 (III)

In this article, we continue mastering API and WebRequest in MQL5 by retrieving candlestick data from an external source. We focus on splitting the server response, cleaning the data, and extracting essential elements such as opening time and OHLC values for multiple daily candles, preparing the data for further analysis.
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Timeseries in DoEasy library (part 53): Abstract base indicator class

Timeseries in DoEasy library (part 53): Abstract base indicator class

The article considers creation of an abstract indicator which further will be used as the base class to create objects of library’s standard and custom indicators.
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Build Self Optimizing Expert Advisors in MQL5 (Part 2): USDJPY Scalping Strategy

Build Self Optimizing Expert Advisors in MQL5 (Part 2): USDJPY Scalping Strategy

Join us today as we challenge ourselves to build a trading strategy around the USDJPY pair. We will trade candlestick patterns that are formed on the daily time frame because they potentially have more strength behind them. Our initial strategy was profitable, which encouraged us to continue refining the strategy and adding extra layers of safety, to protect the capital gained.
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Price Action Analysis Toolkit Development (Part 24): Price Action Quantification Analysis Tool

Price Action Analysis Toolkit Development (Part 24): Price Action Quantification Analysis Tool

Candlestick patterns offer valuable insights into potential market moves. Some single candles signal continuation of the current trend, while others foreshadow reversals, depending on their position within the price action. This article introduces an EA that automatically identifies four key candlestick formations. Explore the following sections to learn how this tool can enhance your price-action analysis.
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Improve Your Trading Charts With Interactive GUI's in MQL5 (Part II): Movable GUI (II)

Improve Your Trading Charts With Interactive GUI's in MQL5 (Part II): Movable GUI (II)

Unlock the potential of dynamic data representation in your trading strategies and utilities with our in-depth guide to creating movable GUIs in MQL5. Delve into the fundamental principles of object-oriented programming and discover how to design and implement single or multiple movable GUIs on the same chart with ease and efficiency.
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Price Action Analysis Toolkit Development (Part 15): Introducing Quarters Theory (I) — Quarters Drawer Script

Price Action Analysis Toolkit Development (Part 15): Introducing Quarters Theory (I) — Quarters Drawer Script

Points of support and resistance are critical levels that signal potential trend reversals and continuations. Although identifying these levels can be challenging, once you pinpoint them, you’re well-prepared to navigate the market. For further assistance, check out the Quarters Drawer tool featured in this article, it will help you identify both primary and minor support and resistance levels.
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Testing and optimization of binary options strategies in MetaTrader 5

Testing and optimization of binary options strategies in MetaTrader 5

In this article, I will check and optimize binary options strategies in MetaTrader 5.
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Advanced Memory Management and Optimization Techniques in MQL5

Advanced Memory Management and Optimization Techniques in MQL5

Discover practical techniques to optimize memory usage in MQL5 trading systems. Learn to build efficient, stable, and fast-performing Expert Advisors and indicators. We’ll explore how memory really works in MQL5, the common traps that slow your systems down or cause them to fail, and — most importantly — how to fix them.
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Trading with the MQL5 Economic Calendar (Part 6): Automating Trade Entry with News Event Analysis and Countdown Timers

Trading with the MQL5 Economic Calendar (Part 6): Automating Trade Entry with News Event Analysis and Countdown Timers

In this article, we implement automated trade entry using the MQL5 Economic Calendar by applying user-defined filters and time offsets to identify qualifying news events. We compare forecast and previous values to determine whether to open a BUY or SELL trade. Dynamic countdown timers display the remaining time until news release and reset automatically after a trade.
Timeseries in DoEasy library (part 47): Multi-period multi-symbol standard indicators
Timeseries in DoEasy library (part 47): Multi-period multi-symbol standard indicators

Timeseries in DoEasy library (part 47): Multi-period multi-symbol standard indicators

In this article, I will start developing the methods of working with standard indicators, which will ultimately allow creating multi-symbol multi-period standard indicators based on library classes. Besides, I will add the "Skipped bars" event to the timeseries classes and eliminate excessive load from the main program code by moving the library preparation functions to CEngine class.
MQL5 Market Turns One Year Old
MQL5 Market Turns One Year Old

MQL5 Market Turns One Year Old

One year has passed since the launch of sales in MQL5 Market. It was a year of hard work, which turned the new service into the largest store of trading robots and technical indicators for MetaTrader 5 platform.
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Population optimization algorithms: Fish School Search (FSS)

Population optimization algorithms: Fish School Search (FSS)

Fish School Search (FSS) is a new optimization algorithm inspired by the behavior of fish in a school, most of which (up to 80%) swim in an organized community of relatives. It has been proven that fish aggregations play an important role in the efficiency of foraging and protection from predators.
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DoEasy. Controls (Part 10): WinForms objects — Animating the interface

DoEasy. Controls (Part 10): WinForms objects — Animating the interface

It is time to animate the graphical interface by implementing the functionality for object interaction with users and objects. The new functionality will also be necessary to let more complex objects work correctly.