Swap and rollover: the cost of holding a trade overnight
So, what is swap / rollover in forex? A swap — also called rollover or an overnight financing charge — is the small interest amount that is either credited to or debited from your account whenever you hold a position past the broker's daily cut-off time. That cut-off is typically 5pm New York time, the point at which one trading day rolls over into the next.
Every forex trade involves two currencies, and each currency has its own short-term interest rate set by its central bank. When you hold a pair overnight, you are effectively borrowing one currency to buy the other. The swap reflects the difference between the interest rate of the currency you are buying and the one you are selling. If the currency you hold pays a higher rate, you may receive a small credit; if it pays a lower rate, you pay a small charge.
If you open and close a trade within the same day — before the cut-off — no swap applies at all. Rollover only ever affects positions carried from one session into the next, which is why it matters far more to swing and position traders than to intraday traders.
Why the interest rate differential drives the swap
The engine behind every swap is the interest rate differential between the two currencies in a pair. Imagine, as an illustrative example, a pair where the base currency's central bank rate is 5% and the quote currency's rate is 1%. A trader holding the higher-yielding currency long sits on the favourable side of that 4% gap and may earn a positive swap, while a trader on the other side pays it.
This long-versus-short distinction is important: the swap on a buy position and a sell position in the same pair are not the same number, and they usually have opposite signs. Buying a pair where you hold the higher-rate currency tends to produce a credit, while selling that same pair tends to produce a charge.
In practice, though, traders rarely receive the full theoretical differential. Brokers apply their own markup to overnight financing, so the swap you actually receive when it is positive is smaller than the rate gap implies, and the swap you pay when it is negative is larger. The headline differential tells you the direction; the broker's published rate tells you the real figure.
Triple swap and how rollover is timed
Swaps are applied once per day at the rollover point, but there is one quirk worth knowing: triple swap day. Because spot forex settles two business days after the trade date, the weekend has to be accounted for during the week. Most brokers do this on Wednesday, charging or crediting three days of swap in a single night to cover Saturday and Sunday.
That means a position held over the Wednesday rollover can incur roughly three times the usual swap, in whichever direction applies to your trade. If you are paying a negative swap, a Wednesday hold is your most expensive night of the week; if you are receiving a positive swap, it is your largest credit. Some brokers use a different day, so check your provider's schedule rather than assuming.
Holidays can shift settlement too, occasionally adding extra swap days around market closures. None of this changes the underlying logic — it simply accounts for days the market is closed but interest still accrues.
How to check the swap before you place a trade
You should never be surprised by a swap, because every regulated broker publishes the figures in advance. On most platforms you can right-click a symbol and open its specification or contract details, where the current long and short swap rates are listed. They are usually quoted in points or in the account currency per lot, per night.
The size of the charge or credit scales with your position size, just like your profit and loss does. A larger lot size means a proportionally larger swap each night, which is why overnight financing can quietly erode the returns on a big, long-held position. Because position size and margin are closely linked, it helps to confirm your exposure first — our margin calculator shows how much margin a given lot size ties up, and our guide to leverage and margin explains how that exposure is built in the first place.
Swap also varies meaningfully from one broker to another, since each adds its own markup. If you trade strategies that routinely hold positions for days or weeks, comparing the overnight rates between brokers is a real cost saving, not a rounding error. It is one of the line items worth checking when you compare brokers.
Swap-free accounts and managing overnight cost
Many brokers offer swap-free, or Islamic, accounts that replace interest-based rollover for clients whose faith prohibits paying or receiving interest. These accounts typically substitute a fixed administration fee on positions held beyond a certain number of days, so they are not necessarily cost-free — they simply restructure how the overnight cost is applied. Read the terms carefully before assuming a swap-free account is cheaper.
If you are not eligible for or interested in a swap-free account, the most direct way to avoid swaps entirely is to close positions before the daily rollover, which is what pure intraday traders do by design. For longer-term traders, the practical approach is to factor the swap into the trade from the outset: a strategy that aims to hold a negative-swap pair for several weeks needs an expected move large enough to absorb the accumulated financing.
Treat swap as one input among many, not a reason to trade. A small positive swap is not a free income stream, because the price of the pair can move against you by far more than any rollover credit. Leveraged forex and CFD trading carries a high risk of loss, and overnight financing is a cost to understand and plan for, never a strategy in itself.