I don't understand why people say you loose money at cex.io, If you purchase $500 in GHash and let them mine for you, any and all btc they mine is profit!  If it looks like the bottom is going to fall out of the market, Just sell the GHash and get your $500 back, You may get a little less or a little more depending on the Price of the GHash when you sell.. You are still making $$$$ while the GHash you purchased is mining for you!!!  This is the way I see it anyway! But everyone has their own ideas about things!