Swap in forex is the interest you pay or receive for holding a position past the daily rollover, usually 5:00 p.m. New York time. Every forex trade borrows one currency to buy another, so you owe interest on one side and earn it on the other. The net difference, plus your broker's markup, is debited or credited each night.
Swap is the second of the two quiet costs in this market. The spread charges you once per trade regardless of how long you hold. Swap charges you once per night regardless of how many trades you took. Day traders who close before the roll never meet it. Swing traders meet it every single night, and after a few weeks it is no longer a rounding error.
Where the charge actually comes from
A spot forex trade is not a purchase in the way buying a share is. Conventionally it settles two business days after the trade date — the value date, written as T+2. If you are still holding when that date arrives, you would in principle have to take delivery of the currency.
Nobody in retail wants that, so the broker performs a rollover: it closes the position for the old value date and simultaneously reopens it for the next one. The price difference between those two value dates is the swap. It reflects the interest rate differential between the two currencies over the period being rolled.
This is not a retail invention. It is the mechanics of one of the largest markets on earth. In April 2025 the Bank for International Settlements measured $4 trillion a day in FX swap turnover, 42% of all global FX trading and the single most-traded FX instrument (BIS, OTC foreign exchange turnover in April 2025). The retail rollover on your platform is the smallest possible slice of that machinery.
How the number on your statement is built
Two inputs and one markup:
- The interest rate differential. You are long one currency and short the other. You earn the short-term rate on the one you hold and pay it on the one you borrowed.
- Your position size. The differential is applied to the full notional, not to your margin. This is where leverage quietly enlarges the bill — see what leverage is and how much is too much.
- The broker markup. A spread applied to the differential, and it is applied in both directions. You pay a little more than the raw rate when swap is negative and receive a little less when it is positive.
A worked illustration makes the scale obvious. Suppose you are long one standard lot — 100,000 units of notional — of a pair where the currency you hold yields 4% a year and the currency you borrowed yields 1%. The raw differential is 3%, or $3,000 a year on that notional, which is about $8.20 a night in your favour before markup. Flip the position and you are paying roughly that much, plus markup, every night you stay in.
| Nights held | Approx. swap at $8.20 a night | Equivalent in EUR/USD pips (1 lot) |
|---|---|---|
| 1 | $8.20 | 0.8 |
| 7 | $57.40 | 5.7 |
| 30 | $246.00 | 24.6 |
| 90 | $738.00 | 73.8 |
The right-hand column is the one that reframes the topic. A month of negative swap on a standard lot is worth roughly 25 pips of adverse movement that has nothing to do with your analysis. On a three-month position it is closer to 75. A swing trader who never checks the swap line is running a slow leak underneath an otherwise sound plan.
Why Wednesday is charged three times
Spot settles T+2 and weekends are not business days. A position rolled on Wednesday moves its value date to Friday; the next roll pushes it to Monday. That is three calendar days of interest, collected in a single entry.
So most brokers post a triple swap on Wednesday. Some use Thursday or Friday depending on how they handle their own settlement, and a handful shift it around public holidays in either currency's home market. Check your own broker's swap schedule rather than assuming the convention — it is usually published in the contract specifications, and being wrong about it means one night in seven is three times the size you expected.
Positive carry, and why it is not free money
When you are long the higher-yielding currency you are credited rather than debited. Holding that position to collect the differential is the carry trade, and it is a genuine strategy operated at enormous scale by institutions — not a loophole.
It is also one of the most reliably punished trades in markets, because the credit accrues in a straight line and the exchange rate does not. The BIS estimated yen carry trade positioning at roughly ¥40 trillion, about $250 billion, before the deleveraging episode of early August 2024, and noted that even this figure is biased downward by data gaps (BIS Bulletin No. 90, The market turbulence and carry trade unwind of August 2024). When that unwound, participants lost far more in days of currency movement than the accumulated carry had paid over months.
The lesson is not that carry is bad. It is that a swap credit is a small tailwind bolted onto full directional risk, and sizing a position because of the credit rather than the setup is how traders end up holding something they never wanted. Position size should come from your stop distance and your risk budget — the method is in how to size a position from risk instead of conviction.
Swap-free and Islamic accounts
Swap-free accounts exist so that traders observing Islamic finance rules can participate without paying or receiving interest. The interest component is removed. The cost usually is not.
Brokers typically substitute one of three things: a flat administration fee per lot per night, a wider quoted spread on the account, or a cap on how many days a position may stay open before the fee starts anyway. All are legitimate. None is free. Compare the total holding cost across the number of nights you actually intend to hold, which is the same discipline that applies to choosing a broker in the first place.
When swap should change your decision
Three practical rules fall out of everything above.
- Check the swap line before you enter a multi-day position, not after. It is in your platform's contract specifications, quoted per lot per night for long and short separately. Thirty seconds of checking prices the trade properly.
- Treat negative swap as part of your cost basis. If the plan is to hold for a month and the swap will eat 25 pips, the target needs to clear the entry, the spread and those 25 pips before the trade is worth taking.
- Never let a swap credit choose the direction. If the setup only works because you are being paid to hold it, it is not a setup.
None of this is an argument against holding overnight. It is an argument for pricing it. The larger risk of carrying a position through the close is not financing but overnight and weekend gap risk, where a stop provides no protection because there is no trading between the two prices.
Frequently Asked Questions
What time is swap charged in forex?
At the daily rollover point, which almost every retail broker sets at 5:00 p.m. New York time. If you are flat at that moment you pay and earn nothing, and if you are holding a position you are debited or credited. Holding a trade for six hours across rollover incurs a full night of financing, while holding one for fourteen hours entirely inside a session incurs none at all. The clock matters more than the duration.
Why is forex swap charged three times on Wednesday?
Because spot forex settles two business days after the trade date and weekends are not business days. A position rolled on Wednesday moves its value date to Friday, and the next roll pushes it to Monday, which is three calendar days of interest rather than one. Brokers collect that in one entry, so most show a triple charge or credit on Wednesday. A few use Thursday or Friday instead, so check your own broker.
Can you earn money from forex swap?
You can be credited rather than debited when you are long the higher-yielding currency and short the lower-yielding one, and that is the basis of the carry trade. It is not free money. The broker markup is applied in both directions, so you earn less than the raw differential, and the currency you are paid to hold can move against you far faster than the credit accumulates. Positive carry is a small tailwind attached to full directional risk.
Do swap-free Islamic accounts really have no cost?
No. Swap-free accounts remove the interest component to comply with Islamic finance rules, but brokers usually replace it with a flat administration fee per lot per night, a wider spread, or a limit on how long a position can stay open. The cost is restructured rather than removed. Compare the total holding cost over the number of nights you actually intend to hold, not the swap line alone.
Bottom line
Swap is the interest bill for keeping a forex position alive overnight, produced by rolling a T+2 value date forward and priced off the gap between two countries' short-term rates plus your broker's markup. Day traders who flatten before 5:00 p.m. New York never pay it; swing traders pay it every night, roughly 25 pips a month on a standard lot in the illustration above, and three times over on Wednesday. Check the number before you enter, treat it as part of the cost basis, and never let a credit pick the direction. The wider market mechanics are in the forex trading guide, and the unit all of this is measured in is explained in what a pip is.