The forex market is open twenty-four hours a day, five days a week — but it is not the same market all day. Trading activity moves around the planet with the business day: Asia hands off to Europe, Europe overlaps with North America, and each handoff changes how much money is actually at the table. Spreads, volatility, and the character of price movement all follow this schedule with remarkable regularity.
Understanding the rhythm matters twice: once for reading any chart honestly, and once more for automation, because a strategy that behaves beautifully in one session can bleed in another for reasons that have nothing to do with its logic.
Three sessions, three personalities
- Tokyo (roughly 00:00–09:00 UTC) — the quietest major session. Ranges compress, spreads on non-yen pairs widen slightly, and price often drifts sideways. Range-trading systems are typically built here.
- London (roughly 07:00–16:00 UTC) — the largest session by volume. The London open frequently produces the day's first genuine directional move, and the deepest liquidity in EUR, GBP, and CHF pairs.
- New York (roughly 12:00–21:00 UTC) — overlaps London for about four hours, and that overlap is the deepest, most liquid window of the entire day. Late New York, after London closes, thins out noticeably.
The setting almost nobody checks: broker server time
Your MetaTrader charts are not stamped in your local time, and usually not in UTC either — they run on the broker's server clock, which commonly sits at GMT+2 or GMT+3 precisely so that the daily candle closes with the New York session. Two traders discussing "the 08:00 candle" on different brokers may be describing different hours of the market. Every session-based rule, backtest, and robot input must be translated into server time before it means anything.
This one detail quietly invalidates more backtests and forum conversations than any other in retail algorithmic trading.
Why the edges cost more than the middle
Session boundaries are where liquidity is thinnest: the minutes around the daily rollover at five o'clock New York time see spreads widen dramatically on many brokers, and the gap between Friday close and the Asian open on Monday can jump straight over stop-losses. Costs concentrate at the edges of the day, which is why many automated strategies simply refuse to trade them. A strategy's session filter is not decoration — it is often the difference between the backtest and the live result.