This is the difference between the Bid price (see) and Ask price (see), it is constantly changing, depending on market conditions: increased demand price or offer price. In a quiet market, floating spread may be less than fixed (which is usually more than 2 points), and in fast-paced, volatile (see) market ir can be significantly higher than it. Trade with floating spread in exactly the same on the real Forex market. However, under these conditions is much harder to test trading strategies. For these purposes it is better to choose accounts with fixed spreads. Select the account with the most comfortable conditions for trade here.