You can change your default currency between USD, AUD, CAD, GBP, EUR, HKD and SGD. Click the USD icon in the navigation bar at the top of the screen, then select another currency from the drop-down menu to change your default currency. You can also change your default currency on the Funding Sources Page by hovering over "Currency Options" under "Default Currency", then click "Change Default Currency" and select another currency from the drop-down menu.

On the Gemini App, you can change your default currency by navigating to the account tab, then tap on the currency under “Default Currency”.