When you are in the trade section, there is an option where you pick flat fee or the default which is the %'s fee. You click the (i) and there is an explanation. And there is also an ROI calculator which you can play around with and you can find out how it works. Basically it answered my question. There are no fees pretty much as long as you lose the trade.

Now here is another question. When I try and put in a stop loss, it seems that the stop loss (even though the trade will be a loss) it seems to register a fee if its triggered. Basically if you are looking at your PnL and you put the stop loss at the current price you will see its much higher than getting out at the market right now. Can anyone confirm what %'s is this stop loss exactly?