If you are a US citizen, then yes to both questions. Trading any asset for another (which would include spending EUR for goods) creates a taxable event, on whi

If you are a US citizen, then yes to both questions. Trading any asset for another (which would include spending EUR for goods) creates a taxable event, on which you must declare your gain on the sold asset based on its fair market value at the time of exchange. There are exemptions for certain types of property (notably section 1031 like kind exchanges for real property). I am not a tax attorney, and more specifically not your tax attorney, nor a certified accountant. https://www.law.cornell.edu/uscode/text/26 https://www.law.cornell.edu/uscode/text/26