Re:Why expat Americans are giving up their passports
by spiralpolitik on Wednesday February 10, 2016 @09:07PM
(#11077779)
Almost all countries tax foreign income of residents. In your example you would be taxed on gains beyond the initial amount in all countries that aren't considered to be tax havens.
(The non-domiciled rule in the UK being one notable exception)
The point being that the US has no business trying to tax income generated from funds that has never entered the country. Residence based taxation (like the rest of the world) would address this immediately.