I'm building some trading robots for a while already but I keep seing that something is wrong with my end of day balances.
My robot does arbitrage across multiple exchanges and I always take into account the fees but for some reason, the numbers are not always as I expect. I suspect that I am either not applying the fees in the right place in my algorithm or maybe I don't have the right fees up to date.
I want to ask you:
Just to make sure that I have the latest fees, do you know where can I get the most reliable information on the fees for the exchanges Cryptsy, Btce, and Bitfinex?
I would like to understand better, for each exchange from which currency the fees are deducted, when buying and selling. Is it the counter or the base currency, that one is charged from? How could I find out this?