“The forex market is open 24 hours” is true and misleading in the same breath. The market is open; the market you actually get — the spread, the depth, the character of movement — changes completely across the day. Knowing the map is one of the cheapest edges available, because it costs nothing but attention.
The three sessions
Forex follows the sun through three financial centres. Times shift with daylight saving, so think in terms of centres rather than fixed hours.
Asia (Tokyo, with Sydney leading in). The quietest major session. Ranges are narrower, and pairs without a regional anchor tend to drift. Yen pairs are the local exception — Japanese data lands here, and USDJPY can be genuinely active while EURUSD sleeps.
London. The largest single centre. Liquidity arrives like a tide: spreads compress, ranges expand, and the day’s direction frequently gets its first honest vote. European data lands in this window.
New York. Overlaps London for its first hours — more on that below — then carries the afternoon alone. US data dominates the calendar here, and the late New York hours thin out toward the daily rollover.
The overlap that matters
For roughly four hours, London and New York trade simultaneously. That window concentrates the deepest liquidity and the tightest spreads of the day, and it hosts a disproportionate share of the day’s meaningful moves — both because the participation is there and because the US data calendar aims at it.
If a trading routine can only cover one window, this is the window. Analysis can happen anywhere in the day; execution benefits from happening where the liquidity is.
The hours that cost money
The rollover hour. After the New York close, liquidity providers step back, spreads widen sharply for a short window, and swap is applied. A stop resting close to price can be executed by the widened spread alone, with no real move behind it. Avoid holding tight-stopped positions through this hour; better, avoid the hour.
Friday’s close and Sunday’s open. Positions held over the weekend meet Monday’s opening price wherever it is — the gap mechanics apply to forex too, and political weekends produce the largest ones. Sunday’s first hours are thin; chasing the open is paying the week’s worst spreads for the week’s least reliable prices.
Pre-news minutes. Before major releases, spreads widen in anticipation. The calendar playbook covers this in full.
Matching the session to the strategy
- Range approaches suit Asia, where mean reversion has statistics on its side — but position for the range to end when London arrives.
- Momentum and breakout approaches want London and the overlap, where a break has participation behind it.
- Swing entries are session-agnostic on analysis but still benefit from executing in liquid hours: entry cost is entry cost.
None of this requires trading at 3am. It requires knowing what 3am is — a thin market with wide spreads and drifting prices — and not applying conclusions formed there to a market that behaves differently eight hours later. The calendar and the clock are the two cheapest instruments in trading; most of what they offer is collected simply by looking.