If you invested 18,500.00 MXP in a USD bank account, it will show on the balance sheet as a 18,500.00 MXP asset. Changes in the exchange rate don't change that fact. The change is only realized as a gain/loss when you buy or sell some or all of the USD. If you want to show changes before then, then the JE is in MXP, with a USD value of zero so it does not change the USD value. QBO USA has a tool for this