Fixed spread shows that the difference between the bid and the ask prices of security remains the same amidst the changing of market conditions. For instance, the spread on the EURUSD will be fixed as 2 even though market condition fluctuates. On the contrary, floating spread shows that the difference between the bid and the ask prices of a security fluctuates from time to time. Fluctuation of spread depends most on the market circumstances, notably during high-impact news release in which the spread could widen significantly.