In forex, a swap is the overnight interest charge or credit applied to positions held past the daily close. It results from the interest rate difference between the two currencies in a pair.
Swap Long vs. Swap Short
- Swap Long — Interest for holding a buy position overnight
- Swap Short — Interest for holding a sell position overnight
Either can be positive (you earn) or negative (you pay).
Example
EUR/USD (EUR rate: 3.75%, USD rate: 5.25%):
- Long EUR/USD: You earn EUR interest, pay USD interest → Net: -1.50% → You pay
- Short EUR/USD: You earn USD interest, pay EUR interest → Net: +1.50% → You earn
Swap Calculation
Daily Swap = (Interest Rate Differential / 365) × Position Value
Key Points
- Swap rates are set by brokers and vary
- Triple swap on Wednesday (weekend settlement)
- Swap-free accounts available (Islamic accounts)
- Can be a significant cost or income for swing traders
- Check your broker’s swap rates in the platform specification