Why do my swap rates triple for positions held over a Wednesday?

If you hold open a position over Wednesday night, the amount added or subtracted to your account as a result of the swap rate charged is three times the usual amount. Triple swap rates are charged in the roll-over period on Wednesday night to account for the settlement of trades over the weekend where no swap rates are charged due to the market being closed. Please note this comes into effect regardless of whether your trade was open during the weekend.