You can install MetaTrader 4 on Mac OS via a free software application PlayOnMac. PlayOnMac is a tool that helps Mac users easily install and run applications that were originally designed to work in Microsoft Windows via Wine. Wine works as a front-end. Please be aware that Wine, like much freeware, does not guarantee absolute stability. Some functions in applications that you run under it may not work correctly or the application may fail to work.
How to install PlayOnMac
To install PlayOnMac: