When is FX actually liquid, and what happens when it is not?

FX is described as a 24-hour market. It is 24 hours for five days, and those hours are not equal. Liquidity follows the working day around the planet, and the spread you pay is a direct function of which working day you are in.

The week, and the sessions

The trading week opens around 17:00 New York time on Sunday — Monday morning in Wellington and Sydney — and closes at 17:00 New York on Friday. In between:

• Asia — Sydney into Tokyo, deepest in JPY, AUD and NZD pairs
• London — the largest FX centre by turnover; European pairs come alive
• New York — US data, US flows
• The overlap — roughly 08:00 to 12:00 New York time, when London and New York are both open. This is the deepest liquidity of the day, by a wide margin.

What the spread does across the day

Illustrative shape for EUR/USD, rounded:

Two structural moments deserve naming. The 17:00 New York roll is when value dates step forward and books are handed between desks — liquidity mechanically thins for a few minutes and quoted spreads widen with it. And scheduled data, such as a major inflation print or a central bank decision, produces a widening in the seconds before release, because no market maker wants to be showing a tight two-way price into a number nobody has seen yet.

The arithmetic that makes this concrete

Cost as a share of the move you are trying to capture:

• A 10-pip objective with a 1.0-pip spread: the spread is 10% of the target
• The same objective with a 3-pip spread: 30%
• A 100-pip objective with a 1.0-pip spread: 1%

Nothing about the market changed between the first two rows — only the hour. This is why execution timing is a cost question long before it is a strategy question, and why costs measured against the notional (0.0074% from Unit 1) and against the objective give such different impressions of the same number.

Exotic pairs are a different market

Everything above described the most liquid pair in the world. Move down the liquidity ladder and the spread on a minor or exotic pair can be five to fifty times a major's, all day, with sharper widening in stress. On some pairs the round-trip cost exceeds a typical day's range — the position must be right by an unusual amount simply to cover the cost of having taken it.

The weekend is not a pause

Prices stop; the world does not. Elections, geopolitical events, policy announcements and central bank decisions occur while the market is closed, and they are expressed all at once when it reopens on Sunday evening. That is the subject of the next lesson, and it is the single most important execution fact in this course.

In the data

The weekly shape is visible in the daily history, which for euro-dollar now carries a row for every day of the week. One week of highs and lows is below.

The weekend rows are nothing like a weekday's. Over the twelve months to 28 September 2026 the median high-to-low range was 48 pips on a weekday, 32 on a Sunday, when the week reopens in the evening, and 6 on a Saturday, when almost nothing trades (measured 29 September 2026). A range comparison that treats every row as one session reads the Saturday stubs as unusually calm markets instead of empty ones.

Try it now

1. A month of daily candles is below. Measure the widest session in it and the narrowest, and put the two pip counts side by side. A factor of three between a busy day and a quiet one is ordinary — and the same spread of outcomes exists inside each of those days, hour by hour, at a scale a daily bar cannot show you.

2. Switch to Weekly. Every quiet session and every weekend gap is now folded inside a single bar, and the market looks calm and continuous. Say in one sentence what a trader working a large order loses by looking at the second chart instead of the first.
3. Take a 15-pip objective and compute what fraction of it the spread consumes at 0.8 pips and at 4 pips. Write both percentages down side by side — that is the difference between the overlap and the thin hours, expressed as the only number that matters.