SWAP RATE
A forex swap rate or rollover is defined as the overnight interest added or deducted for holding a position open overnight. Swap rates are determined by the overnight interest rate differential between the two currencies involved in the pair and whether the position is long or short.
Swaps are applied only when positions are kept open until the next forex trading day which some currency pairs may have negative swap rates on both sides, both ‘long’ and ‘short’.