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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Better Programmer (Part 03): Give Up doing these 5 things to become a successful MQL5 Programmer
Better Programmer (Part 03): Give Up doing these 5 things to become a successful MQL5 Programmer

Better Programmer (Part 03): Give Up doing these 5 things to become a successful MQL5 Programmer

This is the must-read article for anyone wanting to improve their programming career. This article series is aimed at making you the best programmer you can possibly be, no matter how experienced you are. The discussed ideas work for MQL5 programming newbies as well as professionals.
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Larry Williams Market Secrets (Part 14): Detecting Hidden Smash Day Reversals with a Custom Indicator

Larry Williams Market Secrets (Part 14): Detecting Hidden Smash Day Reversals with a Custom Indicator

This article develops a practical MQL5 indicator that identifies Hidden Smash Day bars by strict numeric criteria and optional confirmation on the following session. We cover detection routines, buffer registration, and plot configuration to place arrows at valid bars. The approach delivers stable, non-repainting signals for historical testing and real-time monitoring.
Alternative Log File with the Use of HTML and CSS
Alternative Log File with the Use of HTML and CSS

Alternative Log File with the Use of HTML and CSS

In this article we will describe the process of writing a simple but a very powerful library for making the html files, will learn to adjust their displaying and will see how they can be easily implemented and used in your expert or the script.
Graphical Control of External Parameters of Indicators
Graphical Control of External Parameters of Indicators

Graphical Control of External Parameters of Indicators

External variables of indicators are controlled using a special window where parameters can be changed and the indicator is then run again. The obvious inconvenience of these manipulations has given rise to the need for displaying the required parameters on the screen and controlling the indicator graphically.
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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.
Graphics in DoEasy library (Part 90): Standard graphical object events. Basic functionality
Graphics in DoEasy library (Part 90): Standard graphical object events. Basic functionality

Graphics in DoEasy library (Part 90): Standard graphical object events. Basic functionality

In this article, I will implement the basic functionality for tracking standard graphical object events. I will start from a double click event on a graphical object.
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Population optimization algorithms: Bacterial Foraging Optimization (BFO)

Population optimization algorithms: Bacterial Foraging Optimization (BFO)

E. coli bacterium foraging strategy inspired scientists to create the BFO optimization algorithm. The algorithm contains original ideas and promising approaches to optimization and is worthy of further study.
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Creating a Dynamic Multi-Symbol, Multi-Period Relative Strength Indicator (RSI) Indicator Dashboard in MQL5

Creating a Dynamic Multi-Symbol, Multi-Period Relative Strength Indicator (RSI) Indicator Dashboard in MQL5

In this article, we develop a dynamic multi-symbol, multi-period RSI indicator dashboard in MQL5, providing traders real-time RSI values across various symbols and timeframes. The dashboard features interactive buttons, real-time updates, and color-coded indicators to help traders make informed decisions.
Effective Averaging Algorithms with Minimal Lag: Use in Indicators and Expert Advisors
Effective Averaging Algorithms with Minimal Lag: Use in Indicators and Expert Advisors

Effective Averaging Algorithms with Minimal Lag: Use in Indicators and Expert Advisors

The article describes custom averaging functions of higher quality developed by the author: JJMASeries(), JurXSeries(), JLiteSeries(), ParMASeries(), LRMASeries(), T3Series() and MASeries(). The author considers the hot substitution of these functions in indicators using the call of the SmoothXSeries() function.
Interview with Leonid Velichkovsky: "The Biggest Myth about Neural Networks is Super-Profitability" (ATC 2010)
Interview with Leonid Velichkovsky: "The Biggest Myth about Neural Networks is Super-Profitability" (ATC 2010)

Interview with Leonid Velichkovsky: "The Biggest Myth about Neural Networks is Super-Profitability" (ATC 2010)

The hero of our interview Leonid Velichkovski (LeoV) has already participated in Automated Trading Championships. In 2008, his multicurrency neural network was like a bright flash in the sky, earning $110,000 in a certain moment, but eventually fell victim to its own aggressive money management. Two years ago, in his interview Leonid share his own trading experience and told us about the features of his Expert Advisor. On the eve of the ATC 2010, Leonid talks about the most common myths and misconceptions associated with neural networks.
Trend-Hunting
Trend-Hunting

Trend-Hunting

The article describes an algorithm of volume increase of a profit trade. Its implementation using MQL4 means is presented in the article.
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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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Parallel Particle Swarm Optimization

Parallel Particle Swarm Optimization

The article describes a method of fast optimization using the particle swarm algorithm. It also presents the method implementation in MQL, which is ready for use both in single-threaded mode inside an Expert Advisor and in a parallel multi-threaded mode as an add-on that runs on local tester agents.
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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.
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Category Theory in MQL5 (Part 1)

Category Theory in MQL5 (Part 1)

Category Theory is a diverse and expanding branch of Mathematics which as of yet is relatively uncovered in the MQL community. These series of articles look to introduce and examine some of its concepts with the overall goal of establishing an open library that attracts comments and discussion while hopefully furthering the use of this remarkable field in Traders' strategy development.
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MQL5 Trading Tools (Part 19): Building an Interactive Tools Palette for Chart Drawing

MQL5 Trading Tools (Part 19): Building an Interactive Tools Palette for Chart Drawing

In this article, we build an interactive tools palette in MQL5 for chart drawing, with draggable, resizable panels and theme switching. We add buttons for tools like crosshair, trendlines, lines, rectangles, Fibonacci, text, and arrows, handling mouse events for activation and instructions. This system improves trading analysis through a customizable UI, supporting real-time interactions on charts
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Developing a trading Expert Advisor from scratch (Part 22): New order system (V)

Developing a trading Expert Advisor from scratch (Part 22): New order system (V)

Today we will continue to develop the new order system. It is not that easy to implement a new system as we often encounter problems which greatly complicate the process. When these problems appear, we have to stop and re-analyze the direction in which we are moving.
Enhancing the Quality of the Code with the Help of Unit Test
Enhancing the Quality of the Code with the Help of Unit Test

Enhancing the Quality of the Code with the Help of Unit Test

Even simple programs may often have errors that seem to be unbelievable. "How could I create that?" is our first thought when such an error is revealed. "How can I avoid that?" is the second question which comes to our mind less frequently. It is impossible to create absolutely faultless code, especially in big projects, but it is possible to use technologies for their timely detection. The article describes how the MQL4 code quality can be enhanced with the help of the popular Unit Testing method.
Technical Analysis: How Do We Analyze?
Technical Analysis: How Do We Analyze?

Technical Analysis: How Do We Analyze?

This article briefly describes the author's opinion on redrawing indicators, multi-timeframe indicators and displaying of quotes with Japanese candlesticks. The article contain no programming specifics and is of a general character.
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Introduction to MQL5 (Part 25): Building an EA that Trades with Chart Objects (II)

Introduction to MQL5 (Part 25): Building an EA that Trades with Chart Objects (II)

This article explains how to build an Expert Advisor (EA) that interacts with chart objects, particularly trend lines, to identify and trade breakout and reversal opportunities. You will learn how the EA confirms valid signals, manages trade frequency, and maintains consistency with user-selected strategies.
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Creating Custom Indicators in MQL5 (Part 9): Order Flow Footprint Chart with Price Level Volume Tracking

Creating Custom Indicators in MQL5 (Part 9): Order Flow Footprint Chart with Price Level Volume Tracking

This article builds an order-flow footprint indicator in MQL5 that aggregates tick-by-tick volume into quantized price levels and supports Bid vs Ask and Delta display modes. A canvas overlay renders color-scaled volume text aligned with the candles and updates on every tick. You will learn sorting of price levels, max-value normalization for color mapping, and responsive redraws on zoom, scroll, and resize to read volume distribution and aggressor dominance inside each bar.
CCI indicator. Three transformation steps
CCI indicator. Three transformation steps

CCI indicator. Three transformation steps

In this article, I will make additional changes to the CCI affecting the very logic of this indicator. Moreover, we will be able to see it in the main chart window.
Selection and navigation utility in MQL5 and MQL4: Adding "homework" tabs and saving graphical objects
Selection and navigation utility in MQL5 and MQL4: Adding "homework" tabs and saving graphical objects

Selection and navigation utility in MQL5 and MQL4: Adding "homework" tabs and saving graphical objects

In this article, we are going to expand the capabilities of the previously created utility by adding tabs for selecting the symbols we need. We will also learn how to save graphical objects we have created on the specific symbol chart, so that we do not have to constantly create them again. Besides, we will find out how to work only with symbols that have been preliminarily selected using a specific website.
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Modified Grid-Hedge EA in MQL5 (Part IV): Optimizing Simple Grid Strategy (I)

Modified Grid-Hedge EA in MQL5 (Part IV): Optimizing Simple Grid Strategy (I)

In this fourth part, we revisit the Simple Hedge and Simple Grid Expert Advisors (EAs) developed earlier. Our focus shifts to refining the Simple Grid EA through mathematical analysis and a brute force approach, aiming for optimal strategy usage. This article delves deep into the mathematical optimization of the strategy, setting the stage for future exploration of coding-based optimization in later installments.
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Encoding Candlestick Patterns (Part 1): An Alphabetical System for Signal Detection

Encoding Candlestick Patterns (Part 1): An Alphabetical System for Signal Detection

We present a rule‑based alphabet for candlestick price action that maps measurable shape and direction to letter codes (A/a, H/h, E/e, G/g, D). The article shows an MQL5 implementation: classifying candles, building two‑bar sequences via permutations, and scanning charts with an indicator and alerts. Readers gain a practical template for objective pattern detection and systematic testing.
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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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Introduction to MQL5 (Part 24): Building an EA that Trades with Chart Objects

Introduction to MQL5 (Part 24): Building an EA that Trades with Chart Objects

This article teaches you how to create an Expert Advisor that detects support and resistance zones drawn on the chart and executes trades automatically based on them.
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Experiments with neural networks (Part 5): Normalizing inputs for passing to a neural network

Experiments with neural networks (Part 5): Normalizing inputs for passing to a neural network

Neural networks are an ultimate tool in traders' toolkit. Let's check if this assumption is true. MetaTrader 5 is approached as a self-sufficient medium for using neural networks in trading. A simple explanation is provided.
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Introduction to MQL5 (Part 8): Beginner's Guide to Building Expert Advisors (II)

Introduction to MQL5 (Part 8): Beginner's Guide to Building Expert Advisors (II)

This article addresses common beginner questions from MQL5 forums and demonstrates practical solutions. Learn to perform essential tasks like buying and selling, obtaining candlestick prices, and managing automated trading aspects such as trade limits, trading periods, and profit/loss thresholds. Get step-by-step guidance to enhance your understanding and implementation of these concepts in MQL5.
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Price Action Analysis Toolkit Development (Part 66): Developing a Structured Head and Shoulders Scanner in MQL5

Price Action Analysis Toolkit Development (Part 66): Developing a Structured Head and Shoulders Scanner in MQL5

Head and Shoulders patterns are difficult to identify consistently in live market data due to noise and structural ambiguity. This article presents a structured, triangle-based MQL5 indicator that isolates pattern components, constructs the neckline, and validates formations using ATR, symmetry, and slope constraints. The system detects and draws standard and inverse patterns, assigns a quality score, and confirms breakouts with optional alerts, enabling consistent and rule-based chart analysis.
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Data Science and ML (Part 37): Using Candlestick patterns and AI to beat the market

Data Science and ML (Part 37): Using Candlestick patterns and AI to beat the market

Candlestick patterns help traders understand market psychology and identify trends in financial markets, they enable more informed trading decisions that can lead to better outcomes. In this article, we will explore how to use candlestick patterns with AI models to achieve optimal trading performance.
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Data Science and Machine Learning (Part 06): Gradient Descent

Data Science and Machine Learning (Part 06): Gradient Descent

The gradient descent plays a significant role in training neural networks and many machine learning algorithms. It is a quick and intelligent algorithm despite its impressive work it is still misunderstood by a lot of data scientists let's see what it is all about.
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Population optimization algorithms: Grey Wolf Optimizer (GWO)

Population optimization algorithms: Grey Wolf Optimizer (GWO)

Let's consider one of the newest modern optimization algorithms - Grey Wolf Optimization. The original behavior on test functions makes this algorithm one of the most interesting among the ones considered earlier. This is one of the top algorithms for use in training neural networks, smooth functions with many variables.
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From Novice to Expert: Automating Base-Candle Geometry for Liquidity Zones in MQL5

From Novice to Expert: Automating Base-Candle Geometry for Liquidity Zones in MQL5

This article implements an MQL5 module that analyzes the lower‑timeframe bars inside each liquidity‑zone base candle. It detects swing points and applies objective rules to classify the internal structure as an ascending, descending, or symmetrical triangle; a rectangle; M; W; or undefined. The indicator displays geometry labels on the chart and adds the pattern to alerts, reducing manual lower‑timeframe inspection.
Electronic Tables in MQL5
Electronic Tables in MQL5

Electronic Tables in MQL5

The article describes a class of dynamic two-dimensional array that contains data of different types in its first dimension. Storing data in the form of a table is convenient for solving a wide range of problems of arrangement, storing and operation with bound information of different types. The source code of the class that implements the functionality of working with tables is attached to the article.
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Price Action Analysis Toolkit Development (Part 10): External Flow (II) VWAP

Price Action Analysis Toolkit Development (Part 10): External Flow (II) VWAP

Master the power of VWAP with our comprehensive guide! Learn how to integrate VWAP analysis into your trading strategy using MQL5 and Python. Maximize your market insights and improve your trading decisions today.
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News Trading Made Easy (Part 2): Risk Management

News Trading Made Easy (Part 2): Risk Management

In this article, inheritance will be introduced into our previous and new code. A new database design will be implemented to provide efficiency. Additionally, a risk management class will be created to tackle volume calculations.
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DoEasy. Controls (Part 13): Optimizing interaction of WinForms objects with the mouse, starting the development of the TabControl WinForms object

DoEasy. Controls (Part 13): Optimizing interaction of WinForms objects with the mouse, starting the development of the TabControl WinForms object

In this article, I will fix and optimize handling the appearance of WinForms objects after moving the mouse cursor away from the object, as well as start the development of the TabControl WinForms object.
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Neural networks made easy (Part 67): Using past experience to solve new tasks

Neural networks made easy (Part 67): Using past experience to solve new tasks

In this article, we continue discussing methods for collecting data into a training set. Obviously, the learning process requires constant interaction with the environment. However, situations can be different.
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Neural Networks in Trading: An Agent with Layered Memory

Neural Networks in Trading: An Agent with Layered Memory

Layered memory approaches that mimic human cognitive processes enable the processing of complex financial data and adaptation to new signals, thereby improving the effectiveness of investment decisions in dynamic markets.