There is no loss, money just go from one bank account to another and Bitcoins from one adress to another.
The amount of money in banks stay the same.
yep this is so true i was a bit stupid...
But I'm asking you that because a friend ask me who is loosing the profit we make?
When i buy a btc with some euro, does it mean euro loose some value? If nobody loose, then there is another problem, it mean we are creating wealth. but i don't think so!
Is the loss on transaction fee an explanation? i doubt that.
[EDIT] i think i answer to myself, we just don't make any profit. We make profit if we sell the bitcoins but if everybody sell, then btc price goes back to 0. And some will loose, some will win.