If you need to program Forex strategies, then you may encounter .ex4 files. These are compiled files of MetaTrader 4 Expert Advisors, which can be used to automate trading strategies on the popular Forex trading platform. To open .ex4 files, you’ll need to have the MetaTrader 4 software installed, as this is the only program that can be used to open these files. If the file is encrypted, you may need an unlock code to access the content. Once opened, you’ll have the ability to view the programming code and view how the strategy operates.