MQL4 and MQL5 Programming Articles

icon

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.

Follow our new publications and discuss them on the Forum!

Add a new article
latest | best
preview
Neural networks made easy (Part 71): Goal-Conditioned Predictive Coding (GCPC)

Neural networks made easy (Part 71): Goal-Conditioned Predictive Coding (GCPC)

In previous articles, we discussed the Decision Transformer method and several algorithms derived from it. We experimented with different goal setting methods. During the experiments, we worked with various ways of setting goals. However, the model's study of the earlier passed trajectory always remained outside our attention. In this article. I want to introduce you to a method that fills this gap.
preview
Larry Williams Market Secrets (Part 10): Automating Smash Day Reversal Patterns

Larry Williams Market Secrets (Part 10): Automating Smash Day Reversal Patterns

We implement Larry Williams’ Smash Day reversal patterns in MQL5 by building a rule-based Expert Advisor with dynamic risk management, breakout confirmation logic, and one trade at a time execution. Readers can backtest, reproduce, and study parameter effects using the MetaTrader 5 Strategy Tester and the provided source.
Trading Using Linux
Trading Using Linux

Trading Using Linux

The article describes how to use indicators to watch the situation on financial markets online.
Interview with Valery Mazurenko (ATC 2010)
Interview with Valery Mazurenko (ATC 2010)

Interview with Valery Mazurenko (ATC 2010)

By the end of the first trading week, Valery Mazurenrk (notused) with his multicurrency Expert Advisor ch2010 appeared on the top position. Having treated trading as a hobby, Valery is now trying to monetize this hobby and write a stable-operating Expert Advisor for real trading. In this interview he shares his opinion about the role of mathematics in trading and explains why object-oriented approach suits best to writing multicurrency EAs.
preview
Category Theory in MQL5 (Part 4): Spans, Experiments, and Compositions

Category Theory in MQL5 (Part 4): Spans, Experiments, and Compositions

Category Theory is a diverse and expanding branch of Mathematics which as of yet is relatively uncovered in the MQL5 community. These series of articles look to introduce and examine some of its concepts with the overall goal of establishing an open library that provides insight while hopefully furthering the use of this remarkable field in Traders' strategy development.
preview
Connexus Helper (Part 5): HTTP Methods and Status Codes

Connexus Helper (Part 5): HTTP Methods and Status Codes

In this article, we will understand HTTP methods and status codes, two very important pieces of communication between client and server on the web. Understanding what each method does gives you the control to make requests more precisely, informing the server what action you want to perform and making it more efficient.
preview
The MQL5 Standard Library Explorer (Part 4): Custom Signal Library

The MQL5 Standard Library Explorer (Part 4): Custom Signal Library

Today, we use the MQL5 Standard Library to build custom signal classes and let the MQL5 Wizard assemble a professional Expert Advisor for us. This approach simplifies development so that even beginner programmers can create robust EAs without in-depth coding knowledge, focusing instead on tuning inputs and optimizing performance. Join this discussion as we explore the process step by step.
preview
Statistical Arbitrage Through Cointegrated Stocks (Part 4): Real-time Model Updating

Statistical Arbitrage Through Cointegrated Stocks (Part 4): Real-time Model Updating

This article describes a simple but comprehensive statistical arbitrage pipeline for trading a basket of cointegrated stocks. It includes a fully functional Python script for data download and storage; correlation, cointegration, and stationarity tests, along with a sample Metatrader 5 Service implementation for database updating, and the respective Expert Advisor. Some design choices are documented here for reference and for helping in the experiment replication.
preview
Overcoming The Limitation of Machine Learning (Part 6): Effective Memory Cross Validation

Overcoming The Limitation of Machine Learning (Part 6): Effective Memory Cross Validation

In this discussion, we contrast the classical approach to time series cross-validation with modern alternatives that challenge its core assumptions. We expose key blind spots in the traditional method—especially its failure to account for evolving market conditions. To address these gaps, we introduce Effective Memory Cross-Validation (EMCV), a domain-aware approach that questions the long-held belief that more historical data always improves performance.
preview
Quantitative Analysis of Trends: Collecting Statistics in Python

Quantitative Analysis of Trends: Collecting Statistics in Python

What is quantitative trend analysis in the Forex market? We collect statistics on trends, their magnitude and distribution across the EURUSD currency pair. How quantitative trend analysis can help you create a profitable trading expert advisor.
Ten "Errors" of a Newcomer in Trading?
Ten "Errors" of a Newcomer in Trading?

Ten "Errors" of a Newcomer in Trading?

The article substantiates approach to building a trading system as a sequence of opening and closing the interrelated orders regarding the existing conditions - prices and the current values of each order's profit/loss, not only and not so much the conventional "alerts". We are giving an exemplary realization of such an elementary trading system.
preview
Developing a Replay System — Market simulation (Part 13): Birth of the SIMULATOR (III)

Developing a Replay System — Market simulation (Part 13): Birth of the SIMULATOR (III)

Here we will simplify a few elements related to the work in the next article. I'll also explain how you can visualize what the simulator generates in terms of randomness.
preview
From Novice to Expert: Animated News Headline Using MQL5 (VIII) — Quick Trade Buttons for News Trading

From Novice to Expert: Animated News Headline Using MQL5 (VIII) — Quick Trade Buttons for News Trading

While algorithmic trading systems manage automated operations, many news traders and scalpers prefer active control during high-impact news events and fast-paced market conditions, requiring rapid order execution and management. This underscores the need for intuitive front-end tools that integrate real-time news feeds, economic calendar data, indicator insights, AI-driven analytics, and responsive trading controls.
preview
Larry Williams Market Secrets (Part 3): Proving Non-Random Market Behavior with MQL5

Larry Williams Market Secrets (Part 3): Proving Non-Random Market Behavior with MQL5

Explore whether financial markets are truly random by recreating Larry Williams’ market behavior experiments using MQL5. This article demonstrates how simple price-action tests can reveal statistical market biases using a custom Expert Advisor.
preview
MQL5 Wizard Techniques you should know (Part 51): Reinforcement Learning with SAC

MQL5 Wizard Techniques you should know (Part 51): Reinforcement Learning with SAC

Soft Actor Critic is a Reinforcement Learning algorithm that utilizes 3 neural networks. An actor network and 2 critic networks. These machine learning models are paired in a master slave partnership where the critics are modelled to improve the forecast accuracy of the actor network. While also introducing ONNX in these series, we explore how these ideas could be put to test as a custom signal of a wizard assembled Expert Advisor.
preview
From Basic to Intermediate: Operators

From Basic to Intermediate: Operators

In this article we will look at the main operators. Although the topic is simple to understand, there are certain points that are of great importance when it comes to including mathematical expressions in the code format. Without an adequate understanding of these details, programmers with little or no experience eventually give up trying to create their own solutions.
preview
DoEasy. Controls (Part 31): Scrolling the contents of the ScrollBar control

DoEasy. Controls (Part 31): Scrolling the contents of the ScrollBar control

In this article, I will implement the functionality of scrolling the contents of the container using the buttons of the horizontal scrollbar.
preview
Developing a Replay System (Part 42): Chart Trade Project (I)

Developing a Replay System (Part 42): Chart Trade Project (I)

Let's create something more interesting. I don't want to spoil the surprise, so follow the article for a better understanding. From the very beginning of this series on developing the replay/simulator system, I was saying that the idea is to use the MetaTrader 5 platform in the same way both in the system we are developing and in the real market. It is important that this is done properly. No one wants to train and learn to fight using one tool while having to use another one during the fight.
Terminal Service Client. How to Make Pocket PC a Big Brother's Friend
Terminal Service Client. How to Make Pocket PC a Big Brother's Friend

Terminal Service Client. How to Make Pocket PC a Big Brother's Friend

The article describes the way of connecting to the remote PC with installed MT4 Client Terminal via a PDA.
preview
Developing a Replay System (Part 73): An Unusual Communication (II)

Developing a Replay System (Part 73): An Unusual Communication (II)

In this article, we will look at how to transmit information in real time between the indicator and the service, and also understand why problems may arise when changing the timeframe and how to solve them. As a bonus, you will get access to the latest version of the replay /simulation app.
preview
Multi-Threaded Trading Robot with Machine Learning: From Concept to Implementation

Multi-Threaded Trading Robot with Machine Learning: From Concept to Implementation

The article presents a step-by-step development of a multi-threaded trading robot with machine learning in Python and MetaTrader 5. The system architecture is considered – from data collection and creation of technical indicators to training XGBoost models with portfolio risk management. The implementation of data augmentation, feature clustering via Gaussian Mixture Models, and flow coordination for parallel trading of multiple currency pairs is described in detail.
preview
Package-based approach with KnitPkg for MQL5 development

Package-based approach with KnitPkg for MQL5 development

For maximum reliability and productivity in MetaTrader products built with MQL, this article advocates a development approach based on reusable “packages” managed by KnitPkg, a project manager for MQL5/MQL4. A package can be used as a building block for other packages or as the foundation for final artifacts that run directly on the MetaTrader platform, such as EAs, indicators, and more.
preview
Analyzing Overbought and Oversold Trends Via Chaos Theory Approaches

Analyzing Overbought and Oversold Trends Via Chaos Theory Approaches

We determine the overbought and oversold condition of the market according to chaos theory: integrating the principles of chaos theory, fractal geometry and neural networks to forecast financial markets. The study demonstrates the use of the Lyapunov exponent as a measure of market randomness and the dynamic adaptation of trading signals. The methodology includes an algorithm for generating fractal noise, hyperbolic tangent activation, and moment optimization.
preview
DoEasy. Service functions (Part 2): Inside Bar pattern

DoEasy. Service functions (Part 2): Inside Bar pattern

In this article, we will continue to look at price patterns in the DoEasy library. We will also create the Inside Bar pattern class of the Price Action formations.
preview
Twitter Sentiment Analysis with Sockets

Twitter Sentiment Analysis with Sockets

This innovative trading bot integrates MetaTrader 5 with Python to leverage real-time social media sentiment analysis for automated trading decisions. By analyzing Twitter sentiment related to specific financial instruments, the bot translates social media trends into actionable trading signals. It utilizes a client-server architecture with socket communication, enabling seamless interaction between MT5's trading capabilities and Python's data processing power. The system demonstrates the potential of combining quantitative finance with natural language processing, offering a cutting-edge approach to algorithmic trading that capitalizes on alternative data sources.
Easy Way to Publish a Video at MQL4.Community
Easy Way to Publish a Video at MQL4.Community

Easy Way to Publish a Video at MQL4.Community

It is usually easier to show, than to explain. We offer a simple and free way to create a video clip using CamStudio for publishing it in MQL.community forums.
preview
Neural Networks in Trading: A Complex Trajectory Prediction Method (Traj-LLM)

Neural Networks in Trading: A Complex Trajectory Prediction Method (Traj-LLM)

In this article, I would like to introduce you to an interesting trajectory prediction method developed to solve problems in the field of autonomous vehicle movements. The authors of the method combined the best elements of various architectural solutions.
preview
Feature Engineering With Python And MQL5 (Part IV): Candlestick Pattern Recognition With UMAP Regression

Feature Engineering With Python And MQL5 (Part IV): Candlestick Pattern Recognition With UMAP Regression

Dimension reduction techniques are widely used to improve the performance of machine learning models. Let us discuss a relatively new technique known as Uniform Manifold Approximation and Projection (UMAP). This new technique has been developed to explicitly overcome the limitations of legacy methods that create artifacts and distortions in the data. UMAP is a powerful dimension reduction technique, and it helps us group similar candle sticks in a novel and effective way that reduces our error rates on out of sample data and improves our trading performance.
preview
Tables in the MVC Paradigm in MQL5: Integrating the Model Component into the View Component

Tables in the MVC Paradigm in MQL5: Integrating the Model Component into the View Component

In the article, we will create the first version of the TableControl (TableView) control. This will be a simple static table being created based on the input data defined by two arrays — a data array and an array of column headers.
preview
Neural Networks Made Easy (Part 95): Reducing Memory Consumption in Transformer Models

Neural Networks Made Easy (Part 95): Reducing Memory Consumption in Transformer Models

Transformer architecture-based models demonstrate high efficiency, but their use is complicated by high resource costs both at the training stage and during operation. In this article, I propose to get acquainted with algorithms that allow to reduce memory usage of such models.
preview
MQL5 Wizard Techniques you should know (Part 72): Using Patterns of MACD and the OBV with Supervised Learning

MQL5 Wizard Techniques you should know (Part 72): Using Patterns of MACD and the OBV with Supervised Learning

We follow up on our last article, where we introduced the indicator pair of the MACD and the OBV, by looking at how this pairing could be enhanced with Machine Learning. MACD and OBV are a trend and volume complimentary pairing. Our machine learning approach uses a convolution neural network that engages the Exponential kernel in sizing its kernels and channels, when fine-tuning the forecasts of this indicator pairing. As always, this is done in a custom signal class file that works with the MQL5 wizard to assemble an Expert Advisor.
preview
Creating a Trading Administrator Panel in MQL5 (Part IX): Code Organization (V): AnalyticsPanel Class

Creating a Trading Administrator Panel in MQL5 (Part IX): Code Organization (V): AnalyticsPanel Class

In this discussion, we explore how to retrieve real-time market data and trading account information, perform various calculations, and display the results on a custom panel. To achieve this, we will dive deeper into developing an AnalyticsPanel class that encapsulates all these features, including panel creation. This effort is part of our ongoing expansion of the New Admin Panel EA, introducing advanced functionalities using modular design principles and best practices for code organization.
preview
Low-Frequency Quantitative Strategies in MetaTrader 5 (Part 4): A Volatility-Adjusted Momentum-Based Intraday System

Low-Frequency Quantitative Strategies in MetaTrader 5 (Part 4): A Volatility-Adjusted Momentum-Based Intraday System

We present a timer-based MQL5 EA for Opening Range Breakout aligned to NYSE hours. It screens “Stocks in Play” via opening-range relative volume, enforces price/volume/ATR minimums, sizes positions by risk, and exits at 16:00 ET. A Sharpe-ranked optimization across 30 liquid Nasdaq stocks and a single-symbol test are provided, together with backtest settings and an Excel report for verification.
preview
Developing a Replay System (Part 70): Getting the Time Right (III)

Developing a Replay System (Part 70): Getting the Time Right (III)

In this article, we will look at how to use the CustomBookAdd function correctly and effectively. Despite its apparent simplicity, it has many nuances. For example, it allows you to tell the mouse indicator whether a custom symbol is on auction, being traded, or the market is closed. 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.
preview
Developing a multi-currency Expert Advisor (Part 24): Adding a new strategy (I)

Developing a multi-currency Expert Advisor (Part 24): Adding a new strategy (I)

In this article, we will look at how to connect a new strategy to the auto optimization system we have created. Let's see what kind of EAs we need to create and whether it will be possible to do without changing the EA library files or minimize the necessary changes.
preview
From Basic to Intermediate: Template and Typename (V)

From Basic to Intermediate: Template and Typename (V)

In this article, we'll explore one last simple use case for templates, and discuss the benefits and necessity of using typename in your code. Although this article may seem a bit complicated at first, it is important to understand it properly in order to use templates and typename later.
preview
Neural networks made easy (Part 42): Model procrastination, reasons and solutions

Neural networks made easy (Part 42): Model procrastination, reasons and solutions

In the context of reinforcement learning, model procrastination can be caused by several reasons. The article considers some of the possible causes of model procrastination and methods for overcoming them.
preview
Feature Engineering for ML (Part 3): Session-Aware Time Features for Forex Machine Learning

Feature Engineering for ML (Part 3): Session-Aware Time Features for Forex Machine Learning

The article addresses the loss of temporal information in ML pipelines by encoding periodic time variables with Fourier harmonics and adding forex session structure. It implements session and overlap flags, lagged session volatility, and calendar effects, then prunes features by timeframe. The get time features function returns an index‑aligned, ML‑ready set of time features suitable for integration with price‑based signals.
preview
Python-MetaTrader 5 Strategy Tester (Part 05): Multi-Symbols and Timeframes Strategy Tester

Python-MetaTrader 5 Strategy Tester (Part 05): Multi-Symbols and Timeframes Strategy Tester

This article presents a MetaTrader 5–compatible backtesting workflow that scales across symbols and timeframes. We use HistoryManager to parallelize data collection, synchronize bars and ticks from all timeframes, and run symbol‑isolated OnTick handlers in threads. You will learn how modelling modes affect speed/accuracy, when to rely on terminal data, how to reduce I/O with event‑driven updates, and how to assemble a complete multicurrency trading robot.
preview
Where should your stop-loss really sit? An MAE/MFE excursion analyzer in MQL5

Where should your stop-loss really sit? An MAE/MFE excursion analyzer in MQL5

Stop-loss and take-profit placement is usually the least-measured decision in a trading system. This Expert Advisor reads your closed history, replays M1 price between each entry and exit to measure Maximum Adverse and Favorable Excursion per trade, and splits winners from losers. From the distributions and trade efficiency it derives data-driven stop and target levels - measured from your own account, not a rule of thumb. Analysis only; it does not trade.