Token balance is not correct. and Trade data?

I have installed Tribler 1 week ago on an old Linux notebook and it works slowly but well.

i have downloaded 3 movies total 4.1 GB and the Token balance is 26,0 GB???
I think something is not right

Than i was poking around and found trade? buying data?

Hmmmm gladly an explanation.

Your Tribler instance constantly serves other users as a relay node, earning you credits. That’s why your balance is up. You don’t have to do anything, just leave it running in the background.