What is the swap/rollover in trading?

Swap or rollover refers to the overnight financing adjustment applied when a position remains open into the next trading day. The two terms describe the same mechanism and are used interchangeably across the trading industry. This adjustment accounts for the cost or benefit of maintaining leveraged market exposure beyond the daily settlement cutoff, and it is applied automatically by the platform at a fixed rollover time each trading day.

The swap/rollover exists because leveraged trading positions involve an implicit borrowing arrangement — the trader deposits margin as collateral, and the platform provides the additional exposure needed to reach the full position size. Carrying this arrangement from one day to the next involves a financing cost that reflects prevailing interest rates in the underlying market. In forex, the swap is driven by the interest rate differential between the two currencies in the pair. For other instruments such as stock CFDs, indices, or commodities, the rollover is typically based on a benchmark interest rate plus any instrument-specific adjustments set by the platform.

The swap/rollover amount can vary from day to day as market conditions and interest rates change, and it scales proportionally with the size of the position. Traders should be particularly mindful of the triple swap day, usually Wednesday for forex, when three sessions' worth of financing charges are applied at once to cover the weekend period. For those who actively manage positions held over multiple days, understanding the swap/rollover mechanism is essential for calculating true trading costs, setting realistic profit targets, and deciding whether the expected return on a trade justifies the cumulative financing expense of holding it over the planned timeframe.