For example an ETF in euros that is supposed to mimic gold variations. Because the ETF is in euros, if gold price remains constant, and USD goes up against EUR, the ETF price will go up (since the $x in gold futures the fund has will have more value in euros now). These funds usually hedge EUR/USD so that the ETF mimics gold even in euros, or not? If they don't do that, the ETF price won't mimic gold and it kind of ruins the purpose of an ETF.