Because compilation discards information that is important for human readability — variable names, comments, formatting, and some structural hints. A decompiler can only guess at reconstructing these elements.
Include explicit terms in your EULA that prohibit decompilation, reverse engineering, and redistribution.
Source: GridinSoft malware analysis of the file Ex4 To Mq4 V4 Decompiler Version 4.0 5 Full Version
The story of EX4 to MQ4 V4 Decompiler Version 4.0.5 is a tale of a digital arms race within the world of algorithmic trading. It represents a specific era in the history of the MetaTrader 4 (MT4) platform when the wall between proprietary secrets and open source was briefly torn down. The Origins of the Decompiler
And above all, protect your computer. Many "full versions" floating online are traps. When in doubt, write your own code from scratch. The best strategies come not from theft, but from genuine understanding. Source: GridinSoft malware analysis of the file The
Capability to process multiple files simultaneously. Use Cases for the Decompiler
Years ago, MetaTrader 4 used an older, less secure compiler. During that era, functional decompilers could easily reconstruct accurate .mq4 source code from an .ex4 file. Many "full versions" floating online are traps
An contains the source code written in MetaQuotes Language 4 (MQL4). This is the human-readable code you write and edit in MetaEditor, the integrated development environment that comes with MetaTrader 4. MQ4 files include functions, variables, trading logic, comments, and all the instructions that define how Expert Advisors (EAs), indicators, or scripts behave. If you want to understand, modify, or maintain a trading program, you need access to its MQ4 source file.
files. Furthermore, many files marketed as "full version" or "cracked" versions of these decompilers are flagged as or containing malware by security analysts. Google Groups Risks and Limitations Malware Threat
: Numerous users on community forums like Forex Peace Army and GitHub report that sites selling or offering this "full version" are scams, often taking payment without delivering a working product.
This article is for educational and informational purposes only. Decompiling software may violate copyright laws and software licenses in your country. The author does not provide or link to any decompilation tools. Always consult a legal professional before reverse engineering any software.