The spread is the fee everyone compares. The swap is the fee that actually decides whether holding a position for three weeks made sense. Day traders never meet it; everyone else pays (or occasionally earns) it every night — and it's published, per instrument, before you ever open the trade.
What the overnight charge actually is
For leveraged forex, the swap (also called rollover) is the interest-rate differential between the two currencies in the pair, plus the broker's markup. You're effectively long one currency's interest rate and short the other's; the broker passes that difference through with an admin fee added — majors like CMC and Pepperstone describe deriving their rates from interbank tom-next rates plus a markup in the 1–2.5% range.
Two consequences people miss:
- Swap can be a credit. Hold the higher-yielding currency and the differential can pay you — though the broker's markup eats into it, and on some pairs both directions end up negative.
- It's charged on the full position size, not your margin. At 30:1 leverage, a "small" nightly rate applies to a position 30 times your stake.
The Wednesday triple charge
Spot FX settles two business days after the trade (T+2). A position rolled over on Wednesday night gets a new settlement date of Monday — spanning the weekend — so brokers charge three days of swap in one night, usually Wednesday for forex and metals. And it's broker-specific beyond FX: some brokers apply the triple day on Friday for energies, indices and crypto instead. Don't memorise a rule — check your broker's swap schedule per instrument.
Indices, commodities and crypto work differently
- Index CFDs: financing is typically a benchmark interest rate plus an admin markup (around 2.5% annualised at majors), applied to the position value nightly.
- Commodity CFDs: often priced off the gap between the two nearest futures contracts plus an admin fee — so the "swap" partly reflects the futures curve, not interest rates.
- Crypto CFDs: the expensive one. Financing is usually charged in both directions (long and short), applied seven days a week because crypto never closes, at rates the broker sets itself. Holding leveraged crypto CFDs for weeks is one of the most reliably costly things you can do with a trading account.
A worked example
Illustrative numbers — check your broker's live rate. Suppose EUR/USD swap long is −0.70 pips per night on a 1-lot position (100,000 units): that's about $7 per night. A two-week hold is 14 nights, but two of them are triple-charged Wednesdays, so you pay for 18 nights ≈ $126 — on a trade where you may have been celebrating saving $5 on the spread. The swap, not the spread, is the number that matters at that holding period.
"Swap-free" accounts aren't free
Islamic/swap-free accounts remove the interest swap, but brokers replace it: typically a fixed administrative fee per lot after a grace period, wider spreads, or both — Exness, for instance, documents an admin-fee regime on overnight orders alongside its swap-free status. Read the swap-free fee table, not the banner. For how account types change the maths generally, see spread-only vs raw-spread accounts.
Find the exact number before you trade
You never need to guess:
- In MT4/MT5: right-click the instrument in Market Watch → Specification → the live Swap long and Swap short values for that symbol.
- On the broker's site: most publish per-instrument swap values in their contract specifications — XM, for example, lists swap values in its instrument specification pages, and that live figure is the answer to "what does holding this overnight at XM cost."
- Rates change daily with interest rates — a figure from last month is trivia, not a cost estimate.
The swap belongs in your all-in cost the moment your holding period passes a day or two — see the real cost of every trade for how it stacks with spread, commission and conversion fees.
Educational content, not financial advice. Illustrative figures only — your broker's published rates are the real ones.