Hi there,
Metatrader 4 and 5 both require Wine to run on Linux. If you or someone else enabled Wine to work easily with Flatpak then these apps could be added to Flathub and be available for Endless users. I’d love to see this happen but doing this work isn’t a high priority for Endless engineers.
There’s an older thread discussing Wine on the forum which has a little bit more info (note, since then we’ve enabled Steam on Endless OS).