USA expatriation taxes are quite steep. I'm not a lawyer, but I believe that all unrealized gains of all assets are taxed upon exit as if the assets were being

USA expatriation taxes are quite steep. I'm not a lawyer, but I believe that all unrealized gains of all assets are taxed upon exit as if the assets were being sold. Further, I think that income generated by through US companies (like investments) are taxed as US income for ten years after renouncing citizenship. Also, forget about coming back (say for a friend's wedding or an important medical procedure), the laws assume that high net worth individuals are leaving to avoid future taxes.