‘Swap’ is the term used to represent the interest that is received/given for keeping a trade open past end of day (5pm EST). Swap rates are derived from the interest rates of the central banks of the two currencies in a pair.
Swap short is when you keep a short position (Sell) open overnight. Swap Long is when you keep a long (Buy) position open overnight.
To calculate the swap fee, you can use the following formula:
Swap Long: One Point x Trade Size x Swap Long in Points
Swap Short: One Point x Trade Size x Swap Short in Points
Here are two examples to show how this calculation works. It will show how you can lose, but also gain money through swaps.
0.01 x 100 x 2.5272 = 2.53 USD
This means that you would receive $2.5272 in swap fees for keeping 1 lot short of XAUUSD past end of day.
0.00001 x 100,000 x -4.98 = -4.98 USD
This means you'd pay $4.98 in swaps for keeping 1 lot short of USDCAD past end of day.
If you are unsure of what the figures in the above equations are, or where they can be found, here is a short explanation on each:
One Point = 0.00001 in EURUSD as point is the last digit in the price
Trade Size = Lots * Contract Size = 100,000
Swap Long in Points = -4.98on a Long position on USDCAD
Something to note is that with pairs that close on weekends, there will be a triple swap charged. This is charged on a certain day, usually a Wednesday but in some cases can be another day, to make up for the 2 days that the market is closed.
You can check the swap values, contract sizes, swap long, swap short and triple swap days for different instruments in the Symbol properties window on the mobile app. On desktop app right click on a symbol in the Market Watch window and select "Specification".