Factors that can influence the forex spread include market volatility, which can cause fluctuation. Major economic indicators, for example, can cause a currency pair to strengthen or weaken – thus affecting the spread. If the market is volatile, currency pairs can incur gapping, or the currency pair becomes less liquid, so the spread will widen.
Keeping an eye on our economic calendar can help prepare you for the possibility of wider spreads. By staying informed as to what events might cause currency pairs to become less liquid, you can make an educated prediction as to whether their volatility might increase, and thus whether you might see a greater spread. However, breaking news or unexpected economic data can be difficult to prepare for.
During the major forex market sessions, such as in London, New York and Sydney, there are likely to be lower spreads. In particular, when there is an overlap, such as when the London session is ending and the New York session is beginning, the spread can be narrower still. The spread is also influenced by the general supply and demand of currencies; if there is a high demand for the euro, the value will increase.