I buyed 250 GHS and realise he mines only with 16%, 84% goes for costs to cex where is logic!!!!!
U loose money 100% take calc in hand!
How did you get the 84% figure?
I don't use cex.io, but from my calculation, it seems the fee is about 30% now (the fee% went down considerably because of the price rise in the past few days).
You are correct that the current fee is ~30%. The algorithm is here: