A swap/rollover fee is charged when you keep a position open overnight. A forex swap is the interest rate differential between the two currencies of the pair you are trading, and it is calculated according to whether your position is long or short.
Swap calculation
You can use the following formula to calculate your Daily Overnight Interest amount:
No Of nights * Swap (buy or sell) *No of Lots*Point value
❗️Point value = Contract size *No of Decimals in the Pair.
***Depending on the symbols, on either Wednesday or Friday at 23.59 server time, triple/weekend swap occurs. This means if you have a position open it is charged 3 times***
The reason for this is that most instruments have a two-day settlement period. For example, a trade that occurred on Monday settles on Wednesday, a trade that occurred on Tuesday settles on Thursday, a trade that occurred on Wednesday settles on Friday, but a trade that occurred on Thursday settles on the following Monday.
In this example, the trade that occurred on Thursday rolled through the weekend because the banks are closed on Saturday and Sunday. Triple rollover interest is applied to positions held open at 5 pm New York time on Wednesday as this time marks the beginning of the new 24-hour trading day (Thursday).