Ad user account control bitstamps

It is important to know the direction of the trend. I'm researching Python Coding and there's a question that popped up after watching this video: Once that the code is backtested, where does is it run. Kind Regards, Demo version doesn't require the api from the exchange. The very scheme of the process is simple: we buy a crypt on one exchange (where the lowest price is), sell it on another (where the highest), go back and repeat the process in a circle.