What is MQL5? The Appeal of MT5 Automated Trading EA Development
Basics of MQL5 and the MT5 Platform
MQL5 is a programming language used on the MetaTrader 5 (MT5) platform. MT5 is an FX trading platform used worldwide, and by using MQL5, you can create your own automated trading EAs and custom indicators. EAs monitor the market 24/7 and execute trades automatically based on set rules, enabling efficient trading that is not influenced by emotions. The MT5 platform comes equipped with advanced chart analysis tools, a variety of order types, backtesting capabilities, and more, providing a powerful environment for traders to develop and optimize trading strategies. MQL5 maximizes these features and is key to building sophisticated automated trading systems. MQL5, short for MetaQuotes Language 5, has a syntax similar to C++ and is relatively easy for beginners to learn. Through systematic study, you can acquire the skills needed for automated trading EA development.
Benefits of Developing Automated Trading EAs
The biggest advantage of developing an automated trading EA is the automation of trades. This allows you to execute consistent trading strategies without being bound by time or location. Additionally, by using backtesting, you can evaluate and improve the EA’s performance based on historical data. Eliminating emotional judgment and strictly following pre-set rules leads to consistent trading results. Moreover, running multiple EAs simultaneously can diversify risk and enhance overall portfolio stability. Automated trading has fewer time constraints compared to discretionary trading, allowing you to devote time to other activities, making it suitable for part‑time traders and busy business professionals. System trading maintains calm judgment by operating based on objective data rather than emotions.
Preparing the MQL5 Development Environment
By installing the MT5 platform and launching MetaEditor, you can set up the MQL5 development environment. MetaEditor is an integrated development environment (IDE) for writing, compiling, and debugging MQL5 code. It offers various tools for efficient MQL5 programming, such as syntax highlighting, auto‑completion, and debugging features. The MT5 platform can be downloaded for free from its official website. After installation, start MetaEditor and create a new MQL5 file to begin developing EAs and indicators. MetaEditor also includes the MQL5 reference documentation, making it easy to look up functions and syntax. Numerous sample codes are available, allowing beginners to start learning relatively easily.
Fundamentals of MQL5 Programming
Variables, Data Types, and Operators
We explain variables, data types (integers, floating-point numbers, strings, etc.), and operators (arithmetic operators, comparison operators, logical operators), which are the fundamental elements of MQL5 programming. Understanding these elements enables you to write MQL5 code effectively. A variable is a named storage location for data, and a data type defines the kinds of data a variable can hold. Operators are used to manipulate variables and values. MQL5 supports basic data types such as int, double, string, bool, and you can also define custom data types as needed. Arithmetic operators (+, -, *, /, etc.) are used for numeric calculations, comparison operators (==, !=, >, <, etc.) are used for value comparison, and logical operators (&&, ||, !, etc.) are used to combine multiple conditions. By combining these basic elements, you can describe complex processing.
Functions and Control Structures
This section explains how to define and call functions in MQL5, as well as how to use control structures (if statements, for loops, while loops, etc.). Using functions increases code reusability and allows you to break down complex processes. Control structures are essential for managing the program’s execution flow. A function is a block of code that performs a specific task, can accept arguments, and return a value. Using functions improves code readability and maintainability. An if statement executes a specific code block when a condition is true, a for loop repeats a code block a specified number of times, and a while loop repeats a code block as long as a condition remains true. By combining these control structures, you can implement complex logic. Functions and control structures are very important concepts in MQL5 programming.
Event Handling
In MQL5, you use event handlers such as OnTick(), OnInit(), and OnDeinit() to write code that responds to specific events (price changes, EA initialization, EA termination, etc.). Understanding event handling allows you to run an EA based on real-time market data. The OnTick() event is called every time a new tick (price change) occurs, and the OnTrade() event is called when a trade is executed. The OnInit() event is called once when the EA is attached to a chart, and the OnDeinit() event is called once when the EA is removed from the chart. By writing the EA’s logic inside these event handlers, you can automatically execute trades according to market conditions. Event-driven programming is a key element of EA development in MQL5. Mastering event handling enables you to build advanced automated trading systems.
EA Development Using Technical Indicators
Using Bollinger Bands
This article explains how to calculate Bollinger Band values in MQL5 and generate trading signals based on those values. By using the iBands() function, you can easily retrieve the upper, lower, and middle band values. Bollinger Bands consist of a moving average line with lines added at multiples of the standard deviation above and below it, representing price volatility. When the price approaches the upper band, it can be considered overbought; when it approaches the lower band, it can be considered oversold. Using iBands(), you can calculate Bollinger Band values based on the specified period, type of moving average, and standard deviation multiplier. These values can then be used to generate buy or sell signals and incorporated into an EA. Bollinger Bands can be employed in various trading strategies, such as trend-following and contrarian approaches.
Reference Sites
Using RSI
This section explains how to calculate the RSI (Relative Strength Index) value in MQL5 and generate trading signals based on that value. By using the iRSI() function, you can easily obtain the RSI value. RSI is an indicator that measures the strength of price movements over a given period and is expressed on a scale from 0 to 100. Generally, an RSI above 70 indicates overbought conditions, while an RSI below 30 indicates oversold conditions. Using iRSI(), you can calculate the RSI value based on the specified period and price type. These values can then be used to generate buy or sell signals and incorporated into an EA. RSI can be used to assess trend strength and turning points. Combining RSI with other technical indicators can produce more reliable trading signals.
Combining Multiple Indicators
This section explains how to combine Bollinger Bands and RSI to generate more reliable trading signals. By combining multiple technical indicators, you can reduce false signals and achieve higher precision in trades. For example, you might generate a buy signal when the price approaches the lower Bollinger Band while RSI falls below 30. Conversely, a sell signal could be generated when the price nears the upper Bollinger Band and RSI exceeds 70. Combining indicators helps offset each one’s weaknesses and leads to more accurate trade decisions. However, it is important to consider the correlation between the combined indicators and avoid over‑optimization. Using multiple indicators allows you to build more complex trading strategies.
Creating and Backtesting an EA
Basic Structure of an EA
We explain the basic structure for creating an EA in MQL5. Using event handlers such as OnInit(), OnTick(), and OnDeinit(), you describe EA initialization, processing during price changes, and EA termination. The OnInit() function runs once when the EA is added to the chart, performing initial settings. The OnTick() function runs each time a new tick (price change) occurs, describing the main logic such as checking trade conditions and placing orders. The OnDeinit() function runs once when the EA is removed from the chart, freeing resources. Proper use of these event handlers allows efficient and stable EA development. Understanding the basic structure of an EA is the first step in EA development. By thoroughly understanding the structure, you can develop more complex EAs.
Placing and Managing Orders
We explain how to place and manage orders in MQL5. Use the OrderSend() function to place buy or sell orders, and use OrderClose() to close positions. For order management, functions such as OrderSelect(), OrderModify(), and OrderDelete() are used. The OrderSend() function is used to place new orders, specifying parameters such as order type (buy or sell), volume, price, stop loss, take profit, etc. The OrderClose() function is used to close existing positions, specifying the ticket number and closing price. The OrderSelect() function selects a specific order from the order history, and OrderModify() modifies an existing order. OrderDelete() deletes unfilled orders. Proper use of these functions allows accurate control of automated trading by the EA. Placing and managing orders is a very important element in EA development.
Running Backtests and Optimization
We explain how to evaluate an EA’s performance based on historical data using MT5’s Strategy Tester. By analyzing backtest results and optimizing EA parameters, you can achieve higher profitability. The Strategy Tester is a tool that simulates EA performance using past price data. Running a backtest lets you understand how the EA behaved in past markets and identify potential issues and improvements. When analyzing backtest results, it is important to check metrics such as total profit, profit factor, and maximum drawdown. When optimizing EA parameters, using optimization methods such as genetic algorithms can help find the optimal parameter combination. However, excessive optimization can cause the EA’s performance to deteriorate in future markets, so caution is needed. Backtesting is an essential process in EA development.
Summary: Let’s Start Developing Automated Trading EAs with MQL5
MQL5 is an essential language for developing automated trading EAs on the MT5 platform. By mastering the basics and incorporating technical indicators, you can achieve efficient trading. Challenge yourself to develop EAs with MQL5 and experience the world of automated trading. Learning MQL5 programming may feel difficult at first, but by understanding the fundamental concepts and gradually building on sample code, you will definitely master it. Developing automated trading EAs requires advanced skills, but mastering it can unlock the potential to earn stable income without being tied to time or location. So, take on the challenge of developing EAs with MQL5 and experience the world of automated trading.
Reference Sites
＜はじめに＞ このサイトはプログラミング言語MQL5で、MT5用のEA(自動売買プログラム:エキスパートアドバイザー)を…
MQL5: MetaTrader 5取引プラットフォームにビルトインされた取引ストラテジーの言語があれば、ご自分の自動売…
