Cex.io was always a bad investment. Only affiliates won from it.
Now it is profitable. I made some through mining and trading. Just give it a try. Buy at much lower price and sell it at higher price. Will take a few hours to execute the order. Need to be patient.
~~MZ~~
The problem with this plan is that the price of GHs will always decline over the long term as they have a finite amount of time before they will stop (when maintenance costs exceed mining revenue). You may get lucky and have the price of Ghs lower then it would normally be and be able to sell it later at a higher price due to changes in supply and demand however the same can be done with every other kind of asset.