# roll

One of the ongoing research projects inside the Robot Wealth community involves an FX strategy with some multi-week hold periods. Such a strategy can be significantly impacted by the swap, or the cost of financing the position. These costs change over time, and we decided that for the sake of more accurate simulations, we would incorporate these changes into our backtests. This post shows you how to simulate variable FX swaps in both Python and the Zorro trading automation software platform. What is Swap? The swap (also called the roll) is the cost of financing an FX position. It is typically derived from the central bank interest rate differential of the two currencies in the exchange rate being traded, plus some additional fee for your broker. Most brokers apply it on a daily basis, and typically apply three times the regular amount on a Wednesday to account for the weekend. Swap can be both credited to and debited from a trader's account, depending on the actual position taken. Why is it Important? Swap can have a big impact on strategies...