To calculate your profit or loss for a Long trade, please use the following formula:
PL = S * M * ( Ec / E0 – 1 ) – C , where:
PL is your profit or loss
S is your investment amount
M is the multiplier value in use
Ec is the close price
Eo is the open price
C is commission charged for your transaction
To calculate your profit or loss for a Short trade, please use the following formula:
PL = S * M * ( 1- Ec / E0) – C
Let's assume you have opened a long Dow Jones trade worth 1,000 USD with multiplier at 10, at 15,345 and closed it at 15,515, your transaction fee being 1.70 USD, and the rollover fee at - 3.80 USD.
Thus, what we get is: 1,000 * 10 * ( 15,515 / 15,345 – 1) – 1.70 – 3.80 = 105.28 USD.
Your transaction profit is 105.28 USD.
Now let's assume we open an identical trade, but a short one:
1,000 * 10 * (1 – 15,515 / 15,345) – 1.70 – 0.20 = -112.68 USD
Here, your loss would be 112.68 USD.