Most people think of the forex spread as a fixed number, like the price tag on a shirt. It's not. It's more like the price of a taxi: cheap and easy at noon, surprisingly expensive in a storm or at 3 a.m. when there are hardly any drivers around. To really understand it, let's spend a whole day with the world's most traded currency pair, EUR/USD, and watch how its spread changes from hour to hour. All times below are in London time, and the spreads are illustrative, not quotes from any specific broker. Sunday, 10 PM: The Nervous Open The market reopens after the weekend. Banks in Sydney and Wellington are waking up, but most of the world is still asleep. Liquidity is thin. Prices may jump, or "gap," from where they closed on Friday. The spread is at its widest of the week. Something that m ...