A Forex rollover rate is defined as the interest added or deducted for holding a currency pair position open overnight. These rates are calculated as the difference between the overnight interest rate for two currencies that a Forex trader is holding whether long (buying a currency pair) or short (selling a currency pair). Knowing the rollover or swap rate can be important for calculating profits and losses for any positions held overnight. Educate yourself to find out which rate is being charged and the base currency the interest rate is using. Rollover/swap rates may change frequently, so review this page often if considering holding several currency pair positions overnight. Holding positions overnight can cause debits or credits in interest posted to an account and during the rollover period; the interest is automatically added.