Swap costs

In real trading, the swap costs of course can change a lot in different brokers and throughout time but they are an essential part of overall costs in long term strategies. Therefore it's important for the trader to have some way to simulate these costs. Even if the swap costs that one would use in a simulation cannot be totally exact, the total absence of possibility to allocate the costs of having trades open for a long period of time is the worst case scenario and least exact option of all. 


Due to the variable nature of this cost, it would also be important to be able to run robustness costs around this parameter because different strategies will be more or less sensitive to variations of this cost depending on the time range the trades are maintained open.