Probably the easiest way of understanding how a CFD works is to follow an example. Lets assume that you want to trade Ericsson B CFDs and that Impeo's price is 23.3 / 23.4

Example 1 (long position)

You believe that Ericsson will rise in the near future and decide to go long and buy at the price 23.4. You want to buy 10000 CFDs at a value of 234000 SEK. Since the margin is only 10% you only need to pay 23400 SEK in order to open your position. A provision of 0.15% is paid upon opening the position.

Contrary to what you believed the price drops in the coming days to 22.1 / 22.2. You decide to minimize your loss and close your position at the price 22.1. Your loss is (22.1 - 23.4)*10000 = -13000 SEK (price difference * the number of contracts). A provision of 0.15% is withdrawn upon closing the position as well making the total loss -13000 - 0.15%*234000 - 0.15%*221000 = -13683 SEK.

Example 2 (short position) 

You believe that Ericsson will fall in value in the near future and decide to go short and sell at the price 23.3. You want to trade 10000 CFDs at a value of 233000 SEK. Since the margin is only 10% you only need to pay 23300 SEK in order to open your position. Again a  provision of 0.15% is paid upon opening the position.

Your assumptions turn out to be true and the price drops. You wait until the price seems to level out at the price 21.4 / 21.5 and then buy at the price 21.5 in order to close your position. Your profit is (23.3 - 21.5)*10000 = 18000 SEK (price difference * the number of contracts). Taking into account the provision for opening and closing the position the total profit is 18000 - 0.15%*233000 - 0.15%*215000 = 17328 SEK.

Since you held your positions over one or several nights there is also financing to take into account, which is debited from your account for long positions and credited to your account for short positions.

For more information on financing click here.