Direct answer: what “interest rate” means in forex
In forex, what people call an “interest rate” is usually not a bank-style interest paid on your account balance. It is typically the swap (also called rollover or carry) that reflects the interest-rate difference between the two currencies in the pair, applied to an open position over time.
If a platform like forex.com shows an “interest rate,” it generally describes the rule that turns that currency-rate difference into a daily (or otherwise periodic) cash adjustment for holding the position.
How it works in principle (mechanics)
A common way to think about forex swap/carry is:
- A currency pair has two currencies (for example, Currency A and Currency B).
- Each currency is associated with an interest-rate expectation.
- The platform’s calculation uses the difference between the two currencies’ rates, then applies it to your open exposure.
- Your contract’s specifics determine how that differential becomes money: whether the position earns or costs (credit vs. debit), and the periodicity (how often the swap is applied).
Material assumptions and limitations:
- The “rates” behind carry are not identical across every provider; they can be based on the provider’s internal referencing and instrument terms.
- The conversion from the differential to the final amount depends on trade details such as direction (long/short), the base/quote currency of the pair, and the contract sizing.
Example checks you can do without assuming provider-specific formulas
Because no live provider documentation is included here, you should treat the exact numeric formula as provider-specific. You can still verify the concept independently:
- Compare holding a position versus being flat. If the account shows a periodic adjustment tied to time, that supports the “swap/carry” interpretation.
- Check sign changes. Swapping a position from long to short (keeping everything else constant) often flips whether the adjustment is a cost or credit.
- Look for the disclosed adjustment line item (the swap/rollover entry) that corresponds to your position’s instruments and time.
Relevant limitations and risks
- “Interest rate” labels can be ambiguous. Some pages show a rate differential, while others show a monetized swap amount; mixing them can lead to misunderstandings.
- Carry is not predictable in a simple way. If the underlying currency-rate expectations move, the swap adjustment can change even if you do nothing.
- Swap affects the long-run profitability differently from the price move. A position can be profitable on price movement while still incurring meaningful carry costs, or vice versa.
- Any precise statement about forex.com’s exact inputs, timing, and sign conventions requires provider-specific documentation; without that, only the general mechanism can be described.