Reference

Rollover: the overnight cost most retail traders forget.

Holding a forex position past the daily 22:00 GMT cut-off triggers a swap charge or credit based on the interest-rate differential between the two currencies. Over weeks and months, the cumulative effect on P&L is substantial.

What rollover is

Spot FX trades settle T+2. A position held past the daily 22:00 GMT cut-off is technically rolled forward by one day — the broker's settlement system extends the settlement date. The interest-rate differential between the two currencies in the pair is applied as a credit or debit, calibrated to the 1-day forward rate.

Mechanism: when you're long the higher-interest-rate currency in a pair, you receive the differential as a daily credit. When you're long the lower-interest-rate currency, you pay the differential as a daily debit. Brokers typically add a markup of 0.5–2 % on the differential, in their favour either way.

Worked example

Long 1 standard lot of AUD/JPY. RBA cash rate 4.10 %, BoJ rate 0.50 %. Differential: AUD over JPY by 3.60 percentage points.

  • Daily rollover credit ≈ position notional × differential / 365 = AUD 100,000 × 0.036 / 365 ≈ AUD 9.86/day.
  • Per month (~22 trading days): ~AUD 217.
  • Per year: ~AUD 3,600 if held continuously.

Same position held short (long JPY, short AUD) would pay roughly the same amount each day. The carry differential dominates the P&L of long-held positions in pairs with large rate differentials.

The carry trade

The classic FX carry trade: borrow in a low-interest-rate currency (historically JPY, recently CHF), convert to a high-interest-rate currency (AUD, NZD, MXN, ZAR), pocket the differential. The strategy works for years, then collapses spectacularly in a single risk-off episode when the high-yield currency depreciates and wipes out accumulated carry. Famous examples: 2008 (JPY repatriation), 2015 (CHF unpegging), early 2020 (broad EM selloff).

Retail traders running unintentional carry trades — long positions in carry-positive pairs held for weeks — are exposed to the same dynamic. The position generates daily credit until the day the cross moves 5–10 % against them in 24 hours and wipes out all accumulated carry plus principal.

Wednesday triple-swap

Spot FX settles T+2. A position held over Wednesday's daily cut-off would settle on Friday; rolled to Thursday-settlement, settle Monday; rolled to Friday-settlement, settle Tuesday. To bridge the weekend, brokers charge or credit triple swap on Wednesday (covering Wednesday, Saturday, Sunday). Holding a carry-negative position over a Wednesday is therefore three times as expensive as a normal day.

Reference: typical daily swap rates (May 2026, indicative)

PairLong swap (per std lot)Short swap (per std lot)Implied annual carry
AUD/JPY+$10/day−$13/day~+3.6% long
NZD/JPY+$11/day−$14/day~+4.0% long
USD/JPY+$15/day−$18/day~+5.5% long
EUR/USD−$1.5/day+$0.5/day~−0.5% long
GBP/USD−$1/day−$1/day~−0.4% long
EUR/CHF+$3/day−$5/day~+1.1% long
USD/MXN+$30/day−$35/day~+11% long (volatile)

What the calculator does not include

The position-size calculator on this site computes pip value and P&L assuming a same-day round-trip. Rollover/swap is not modelled. For positions held overnight, add the daily swap (positive or negative) to the P&L. For multi-week positions, the swap accumulation is often material relative to the pip P&L — particularly for high-rate-differential pairs.