Rollover is a process in forex trading where an open position is extended to the next trading day, which involves the simultaneous closing of the existing position and the opening of a new position for the same currency pair, but with a new value date. The difference in interest rates between the two currencies in the pair is the cost or benefit of rolling the position over to the next day. Rollovers are executed automatically by most brokers at a specific time of day and are subject to rollover interest charges or credits. Rollover can also refer to a swap transaction, which is a financial instrument used to hedge or speculate against currency fluctuations.