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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Neural Network in Practice: Least Squares

Neural Network in Practice: Least Squares

In this article, we'll look at a few ideas, including how mathematical formulas are more complex in appearance than when implemented in code. In addition, we will consider how to set up a chart quadrant, as well as one interesting problem that may arise in your MQL5 code. Although, to be honest, I still don't quite understand how to explain it. Anyway, I'll show you how to fix it in code.
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Markets Positioning Codex in MQL5 (Part 1): Bitwise Learning for Nvidia

Markets Positioning Codex in MQL5 (Part 1): Bitwise Learning for Nvidia

We commence a new article series that builds upon our earlier efforts laid out in the MQL5 Wizard series, by taking them further as we step up our approach to systematic trading and strategy testing. Within these new series, we’ll concentrate our focus on Expert Advisors that are coded to hold only a single type of position - primarily longs. Focusing on just one market trend can simplify analysis, lessen strategy complexity and expose some key insights, especially when dealing in assets beyond forex. Our series, therefore, will investigate if this is effective in equities and other non-forex assets, where long only systems usually correlate well with smart money or institution strategies.
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Overcoming The Limitation of Machine Learning (Part 1): Lack of Interoperable Metrics

Overcoming The Limitation of Machine Learning (Part 1): Lack of Interoperable Metrics

There is a powerful and pervasive force quietly corrupting the collective efforts of our community to build reliable trading strategies that employ AI in any shape or form. This article establishes that part of the problems we face, are rooted in blind adherence to "best practices". By furnishing the reader with simple real-world market-based evidence, we will reason to the reader why we must refrain from such conduct, and rather adopt domain-bound best practices if our community should stand any chance of recovering the latent potential of AI.
Method of Determining Errors in Code by Commenting
Method of Determining Errors in Code by Commenting

Method of Determining Errors in Code by Commenting

The article describes a method of searching the errors in the MQL4 code that is based on commenting. This method is found to be a useful one in case of problems occuring during the compilation caused by the errors in a reasonably large code.
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From Basic to Intermediate: Variables (II)

From Basic to Intermediate: Variables (II)

Today we will look at how to work with static variables. This question often confuses many programmers, both beginners and those with some experience, because there are several recommendations that must be followed when using this mechanism. The materials presented here are intended for didactic purposes only. Under no circumstances should the application be viewed for any purpose other than to learn and master the concepts presented.
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Visual assessment and adjustment of trading in MetaTrader 5

Visual assessment and adjustment of trading in MetaTrader 5

The strategy tester allows you to do more than just optimize your trading robot's parameters. I will show how to evaluate your account's trading history post-factum and make adjustments to your trading in the tester by changing the stop-losses of your open positions.
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Market Simulation (Part 02): Cross Orders (II)

Market Simulation (Part 02): Cross Orders (II)

Unlike what was done in the previous article, here we will test the selection option using an Expert Advisor. Although this is not a final solution yet, it will be enough for now. With the help of this article, you will be able to understand how to implement one of the possible solutions.
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The MQL5 Standard Library Explorer (Part 2): Connecting Library Components

The MQL5 Standard Library Explorer (Part 2): Connecting Library Components

Today, we take an important step toward helping every developer understand how to read class structures and quickly build Expert Advisors using the MQL5 Standard Library. The library is rich and expandable, yet it can feel like being handed a complex toolkit without a manual. Here we share and discuss an alternative integration routine—a concise, repeatable workflow that shows how to connect classes reliably in real projects.
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From Basic to Intermediate: Arrays and Strings (III)

From Basic to Intermediate: Arrays and Strings (III)

This article considers two aspects. First, how the standard library can convert binary values to other representations such as octal, decimal, and hexadecimal. Second, we will talk about how we can determine the width of our password based on the secret phrase, using the knowledge we have already acquired.
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African Buffalo Optimization (ABO)

African Buffalo Optimization (ABO)

The article presents the African Buffalo Optimization (ABO) algorithm, a metaheuristic approach developed in 2015 based on the unique behavior of these animals. The article describes in detail the stages of the algorithm implementation and its efficiency in finding solutions to complex problems, which makes it a valuable tool in the field of optimization.
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Statistical Arbitrage Through Cointegrated Stocks (Part 8): Rolling Windows Eigenvector Comparison for Portfolio Rebalancing

Statistical Arbitrage Through Cointegrated Stocks (Part 8): Rolling Windows Eigenvector Comparison for Portfolio Rebalancing

This article proposes using Rolling Windows Eigenvector Comparison for early imbalance diagnostics and portfolio rebalancing in a mean-reversion statistical arbitrage strategy based on cointegrated stocks. It contrasts this technique with traditional In-Sample/Out-of-Sample ADF validation, showing that eigenvector shifts can signal the need for rebalancing even when IS/OOS ADF still indicates a stationary spread. While the method is intended mainly for live trading monitoring, the article concludes that eigenvector comparison could also be integrated into the scoring system—though its actual contribution to performance remains to be tested.
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Developing a Replay System (Part 68): Getting the Time Right (I)

Developing a Replay System (Part 68): Getting the Time Right (I)

Today we will continue working on getting the mouse pointer to tell us how much time is left on a bar during periods of low liquidity. Although at first glance it seems simple, in reality this task is much more difficult. This involves some obstacles that we will have to overcome. Therefore, it is important that you have a good understanding of the material in this first part of this subseries in order to understand the following parts.
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MQL5 Wizard Techniques you should know (Part 68):  Using Patterns of TRIX and the Williams Percent Range with a Cosine Kernel Network

MQL5 Wizard Techniques you should know (Part 68): Using Patterns of TRIX and the Williams Percent Range with a Cosine Kernel Network

We follow up our last article, where we introduced the indicator pair of TRIX and Williams Percent Range, by considering how this indicator pairing could be extended with Machine Learning. TRIX and William’s Percent are a trend and support/ resistance complimentary pairing. Our machine learning approach uses a convolution neural network that engages the cosine kernel in its architecture 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.
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Brain Storm Optimization algorithm (Part I): Clustering

Brain Storm Optimization algorithm (Part I): Clustering

In this article, we will look at an innovative optimization method called BSO (Brain Storm Optimization) inspired by a natural phenomenon called "brainstorming". We will also discuss a new approach to solving multimodal optimization problems the BSO method applies. It allows finding multiple optimal solutions without the need to pre-determine the number of subpopulations. We will also consider the K-Means and K-Means++ clustering methods.
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Overcoming The Limitation of Machine Learning (Part 2): Lack of Reproducibility

Overcoming The Limitation of Machine Learning (Part 2): Lack of Reproducibility

The article explores why trading results can differ significantly between brokers, even when using the same strategy and financial symbol, due to decentralized pricing and data discrepancies. The piece helps MQL5 developers understand why their products may receive mixed reviews on the MQL5 Marketplace, and urges developers to tailor their approaches to specific brokers to ensure transparent and reproducible outcomes. This could grow to become an important domain-bound best practice that will serve our community well if the practice were to be widely adopted.
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Causal inference in time series classification problems

Causal inference in time series classification problems

In this article, we will look at the theory of causal inference using machine learning, as well as the custom approach implementation in Python. Causal inference and causal thinking have their roots in philosophy and psychology and play an important role in our understanding of reality.
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Generative Adversarial Networks (GANs) for Synthetic Data in Financial Modeling (Part 2): Creating Synthetic Symbol for Testing

Generative Adversarial Networks (GANs) for Synthetic Data in Financial Modeling (Part 2): Creating Synthetic Symbol for Testing

In this article we are creating a synthetic symbol using a Generative Adversarial Network (GAN) involves generating realistic Financial data that mimics the behavior of actual market instruments, such as EURUSD. The GAN model learns patterns and volatility from historical market data and creates synthetic price data with similar characteristics.
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Overcoming The Limitation of Machine Learning (Part 9): Correlation-Based Feature Learning in Self-Supervised Finance

Overcoming The Limitation of Machine Learning (Part 9): Correlation-Based Feature Learning in Self-Supervised Finance

Self-supervised learning is a powerful paradigm of statistical learning that searches for supervisory signals generated from the observations themselves. This approach reframes challenging unsupervised learning problems into more familiar supervised ones. This technology has overlooked applications for our objective as a community of algorithmic traders. Our discussion, therefore, aims to give the reader an approachable bridge into the open research area of self-supervised learning and offers practical applications that provide robust and reliable statistical models of financial markets without overfitting to small datasets.
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Reimagining Classic Strategies (Part 14): High Probability Setups

Reimagining Classic Strategies (Part 14): High Probability Setups

High probability Setups are well known in our trading community, but regrettably they are not well-defined. In this article, we will aim to find an empirical and algorithmic way of defining exactly what is a high probability setup, identifying and exploiting them. By using Gradient Boosting Trees, we demonstrated how the reader can improve the performance of an arbitrary trading strategy and better communicate the exact job to be done to our computer in a more meaningful and explicit manner.
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Integrating MQL5 with data processing packages (Part 3): Enhanced Data Visualization

Integrating MQL5 with data processing packages (Part 3): Enhanced Data Visualization

In this article, we will perform Enhanced Data Visualization by going beyond basic charts by incorporating features like interactivity, layered data, and dynamic elements, enabling traders to explore trends, patterns, and correlations more effectively.
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Applying Localized Feature Selection in Python and MQL5

Applying Localized Feature Selection in Python and MQL5

This article explores a feature selection algorithm introduced in the paper 'Local Feature Selection for Data Classification' by Narges Armanfard et al. The algorithm is implemented in Python to build binary classifier models that can be integrated with MetaTrader 5 applications for inference.
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MQL5 Wizard Techniques you should know (14): Multi Objective Timeseries Forecasting with STF

MQL5 Wizard Techniques you should know (14): Multi Objective Timeseries Forecasting with STF

Spatial Temporal Fusion which is using both ‘space’ and time metrics in modelling data is primarily useful in remote-sensing, and a host of other visual based activities in gaining a better understanding of our surroundings. Thanks to a published paper, we take a novel approach in using it by examining its potential to traders.
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MQL5 Wizard Techniques you should know (Part 47): Reinforcement Learning with Temporal Difference

MQL5 Wizard Techniques you should know (Part 47): Reinforcement Learning with Temporal Difference

Temporal Difference is another algorithm in reinforcement learning that updates Q-Values basing on the difference between predicted and actual rewards during agent training. It specifically dwells on updating Q-Values without minding their state-action pairing. We therefore look to see how to apply this, as we have with previous articles, in a wizard assembled Expert Advisor.
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Analyzing weather impact on currencies of agricultural countries using Python

Analyzing weather impact on currencies of agricultural countries using Python

What is the relationship between weather and Forex? Classical economic theory has long ignored the influence of such factors as weather on market behavior. But everything has changed. Let's try to find connections between the weather conditions and the position of agricultural currencies on the market.
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Neural Networks in Trading: Memory Augmented Context-Aware Learning for Cryptocurrency Markets (Final Part)

Neural Networks in Trading: Memory Augmented Context-Aware Learning for Cryptocurrency Markets (Final Part)

The MacroHFT framework for high-frequency cryptocurrency trading uses context-aware reinforcement learning and memory to adapt to dynamic market conditions. At the end of this article, we will test the implemented approaches on real historical data to assess their effectiveness.
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MQL5 Wizard Techniques you should know (Part 52): Accelerator Oscillator

MQL5 Wizard Techniques you should know (Part 52): Accelerator Oscillator

The Accelerator Oscillator is another Bill Williams Indicator that tracks price momentum's acceleration and not just its pace. Although much like the Awesome oscillator we reviewed in a recent article, it seeks to avoid the lagging effects by focusing more on acceleration as opposed to just speed. We examine as always what patterns we can get from this and also what significance each could have in trading via a wizard assembled Expert Advisor.
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Neural Networks in Trading: Hierarchical Dual-Tower Transformer (Final Part)

Neural Networks in Trading: Hierarchical Dual-Tower Transformer (Final Part)

We continue to build the Hidformer hierarchical dual-tower transformer model designed for analyzing and forecasting complex multivariate time series. In this article, we will bring the work we started earlier to its logical conclusion — we will test the model on real historical data.
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Data Science and ML (Part 44): Forex OHLC Time series Forecasting using Vector Autoregression (VAR)

Data Science and ML (Part 44): Forex OHLC Time series Forecasting using Vector Autoregression (VAR)

Explore how Vector Autoregression (VAR) models can forecast Forex OHLC (Open, High, Low, and Close) time series data. This article covers VAR implementation, model training, and real-time forecasting in MetaTrader 5, helping traders analyze interdependent currency movements and improve their trading strategies.
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From Basic to Intermediate: Operator Precedence

From Basic to Intermediate: Operator Precedence

This is definitely the most difficult question to be explained purely theoretically. That is why you need to practice everything that we're going to discuss here. While this may seem simple at first, the topic of operators can only be understood in practice combined with constant education.
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Population optimization algorithms: Whale Optimization Algorithm (WOA)

Population optimization algorithms: Whale Optimization Algorithm (WOA)

Whale Optimization Algorithm (WOA) is a metaheuristic algorithm inspired by the behavior and hunting strategies of humpback whales. The main idea of WOA is to mimic the so-called "bubble-net" feeding method, in which whales create bubbles around prey and then attack it in a spiral motion.
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From Basic to Intermediate: Overload

From Basic to Intermediate: Overload

Perhaps this article will be the most confusing for novice programmers. As a matter of fact, here I will show that it is not always that all functions and procedures have unique names in the same code. Yes, we can easily use functions and procedures with the same name — and this is called overload.
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Mutual information as criteria for Stepwise Feature Selection

Mutual information as criteria for Stepwise Feature Selection

In this article, we present an MQL5 implementation of Stepwise Feature Selection based on the mutual information between an optimal predictor set and a target variable.
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Ensemble methods to enhance classification tasks in MQL5

Ensemble methods to enhance classification tasks in MQL5

In this article, we present the implementation of several ensemble classifiers in MQL5 and discuss their efficacy in varying situations.
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Visualizing Strategies in MQL5: Laying Out Optimization Results Across Criterion Charts

Visualizing Strategies in MQL5: Laying Out Optimization Results Across Criterion Charts

In this article, we write an example of visualizing the optimization process and display the top three passes for the four optimization criteria. We will also provide an opportunity to select one of the three best passes for displaying its data in tables and on a chart.
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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.
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From Novice to Expert: Market Periods Synchronizer

From Novice to Expert: Market Periods Synchronizer

In this discussion, we introduce a Higher-to-Lower Timeframe Synchronizer tool designed to solve the problem of analyzing market patterns that span across higher timeframe periods. The built-in period markers in MetaTrader 5 are often limited, rigid, and not easily customizable for non-standard timeframes. Our solution leverages the MQL5 language to develop an indicator that provides a dynamic and visual way to align higher timeframe structures within lower timeframe charts. This tool can be highly valuable for detailed market analysis. To learn more about its features and implementation, I invite you to join the discussion.
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Population optimization algorithms: Evolution of Social Groups (ESG)

Population optimization algorithms: Evolution of Social Groups (ESG)

We will consider the principle of constructing multi-population algorithms. As an example of this type of algorithm, we will have a look at the new custom algorithm - Evolution of Social Groups (ESG). We will analyze the basic concepts, population interaction mechanisms and advantages of this algorithm, as well as examine its performance in optimization problems.
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Artificial Tribe Algorithm (ATA)

Artificial Tribe Algorithm (ATA)

The article provides a detailed discussion of the key components and innovations of the ATA optimization algorithm, which is an evolutionary method with a unique dual behavior system that adapts depending on the situation. ATA combines individual and social learning while using crossover for explorations and migration to find solutions when stuck in local optima.
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DoEasy. Controls (Part 33): Vertical ScrollBar

DoEasy. Controls (Part 33): Vertical ScrollBar

In this article, we will continue the development of graphical elements of the DoEasy library and add vertical scrolling of form object controls, as well as some useful functions and methods that will be required in the future.
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Role of random number generator quality in the efficiency of optimization algorithms

Role of random number generator quality in the efficiency of optimization algorithms

In this article, we will look at the Mersenne Twister random number generator and compare it with the standard one in MQL5. We will also find out the influence of the random number generator quality on the results of optimization algorithms.