From lurking around on this community, I learned that optimal investing strategies diverge from one EU Member State to another due to differences in taxation. I am a 20 something and I already lived and worked in 2 EU MS, possibly adding a third in the mix soon and not excluding the possibility that there will be more following. Taxation seems to be designed for people staying in one place, though. Any tips or advice to make investments waterproof to cross-border situations? What happens, for example, if a broker you have been working with is not available in the Member State you are moving to; can you keep investing through them?