Capital at risk. Leveraged forex is a high-risk product and most retail accounts lose money on it. Nothing here is advice or a trading recommendation.
Forex is sold as the market that never sleeps, and the phrase does real damage. It is technically true and practically misleading: the market is continuously open from Monday morning in Asia to Friday afternoon in New York, and it is nothing like uniformly liquid across that window.
The same pair, the same broker, the same order — at two different hours — will cost you different amounts and behave differently. That is not a broker problem. It is the market having a schedule.
Why sessions exist at all
There is no forex exchange. There is a network of banks, brokers and electronic venues quoting prices to each other, and those participants are staffed by people in offices who go home.
When a financial centre's trading day begins, its banks start quoting in size, and the currencies they deal in most get deeper and tighter. When it ends, that depth leaves. The market stays open because somewhere else is awake, but the set of participants — and therefore the price you can actually get — has changed.
Three centres do most of the work, and their hours are usually described roughly as follows.
- Asia-Pacific, anchored on Tokyo, Singapore, Hong Kong and Sydney. Deepest in the yen, the Australian and New Zealand dollars, and regional pairs.
- London, the largest single centre by turnover. This is when European currencies and the majors are most active.
- New York, overlapping London's afternoon and carrying on after it closes.
The exact clock times shift with daylight saving in each region, and they shift independently, so the overlaps get longer and shorter through the year. Your platform's server time is usually not your local time either. Work in one reference — your broker's server clock — rather than converting on the fly.
The overlap is where the market actually is
The single most useful thing to know is that liquidity is not spread evenly. It concentrates in the hours when two large centres are open simultaneously, and above all when London and New York are both trading.
In that window there are more participants quoting, more quoted depth at each price, and the tightest spreads of the day on the major pairs. It is also when the largest moves tend to happen, for the same reason: that is when the volume is there to make them.
The reverse holds in the quiet hours between the New York close and the Asian session properly getting going. Spreads on the majors are typically at their widest, quoted depth is thinnest, and a modest order can move the price more than it would at midday in London.
Rollover: the same widening, every night
There is one predictable disruption in every trading day, and it catches people out constantly.
Once a day, brokers roll open positions to the next value date and settle swap. Most use around 17:00 New York time, though this is a broker setting rather than a market rule, so check yours. For a few minutes around it, liquidity thins and spreads can widen sharply — sometimes to several times their normal level on pairs that are otherwise cheap to trade.
Two consequences follow, and both cost real money.
A stop placed close to the market can be triggered by the widening alone. Nothing happened to the exchange rate. The quote simply widened around it, touched your level, and closed the position. This is legitimate — the price genuinely was there — and it is entirely avoidable by not leaving tight stops sitting inside the rollover window.
Entering a position during rollover pays the widened spread. If the trade is not time-critical, it is close to free money to wait ten minutes.
The swap itself, and why one day of the week carries a triple charge, is covered in forex swap and rollover fees explained.
The weekend gap
The market closes on Friday afternoon in New York and reopens on Sunday evening. In between, the world does not stop: elections happen, central banks speak, conflicts escalate.
When it reopens, the price simply appears where the first quotes are. It does not trade through the intervening levels, so a stop-loss sitting in that range does not execute at its level — it executes at the first available price, which can be far away.
This is the same mechanism that made the 2015 Swiss franc shock so destructive, in miniature and on a schedule. Anyone holding leveraged positions over a weekend is accepting gap risk, and the question is whether the position is sized so that a gap is survivable.
The first hour of the Sunday open is also unusually thin, with wide spreads and erratic quotes as participants come back. It is one of the worst times of the week to open a position and one of the more common times for a badly-placed stop to be filled at a bad price.
Practical rules that follow from all this
- Trade a pair when its own centres are open. Yen pairs have their deepest market in Asia; European crosses in London. This is about the spread you pay, not about which pairs are good.
- Concentrate on the overlap if you are cost-sensitive. The London-New York window is where the majors are cheapest to trade.
- Keep stops away from rollover, or accept the widening. Know your broker's rollover time and treat the minutes around it as a hazard.
- Compare spreads at the hour you actually trade. An advertised average is an average across the day, including hours you will never use. How to read forex spreads explains what the quoted number contains.
- Size weekend positions for a gap. Or do not hold them.
- Do not force a session. A market that is quiet because everyone has gone home is not an opportunity.
The point underneath
Most retail traders think about what to trade and give almost no thought to when. But the cost of the trade, the reliability of the execution and the meaning of the stop distance all change by the hour, and those three things are a large part of what separates a strategy that works on paper from one that works in an account.
The clock is one of the few variables in trading you control completely. Broker execution quality and what slippage costs covers the other half of the same problem.
Session boundaries shift with daylight saving in each region and rollover time is a per-broker setting. Confirm both against your own broker's server clock rather than a generic table.
Frequently Asked Questions
Is the forex market really open 24 hours?
It runs continuously from the Asia-Pacific open on Monday morning local time to the New York close on Friday afternoon, but it is not uniformly liquid across that window. Spreads, depth and the size of a typical move all vary substantially by hour, so "open" and "worth trading" are different questions.
When are forex spreads tightest?
Generally during the overlap when London and New York are both trading, because that is when the largest number of participants and the deepest quoted volume are present simultaneously. Spreads on major pairs are typically widest in the thin hours after the New York close and before Asia is fully active.
Why does my spread widen at the same time every night?
That is the daily rollover, when brokers settle swap and liquidity briefly thins as positions are rolled to the next value date. Most brokers use around 17:00 New York time. Spreads can widen sharply for a few minutes around it, which is why a stop placed close to the market can be triggered by nothing more than the clock.
Should I trade the session that matches my own currency?
Liquidity in a currency is usually deepest while its home market is open, so a pair tends to trade with tighter spreads and more depth during its own sessions. That is a reason to prefer certain hours for certain pairs, not a rule about which pairs to trade.
