None of them. Buy and hold bitcoins
Yes it seems to be the best option atm. The only way to make profit atm with mining is to get a good BTC/GH miner instant on ebay or so ant then instantaneously sell all hash power on cex.io. However it could be risky since affaik you are obligated to offer this hashrate forever. However its likely that you can buyback the hashpower almost free in a few months. So you have the profit of the beginning margin - the elec costs - buyback costs = which is most likely profitable...
Else I didn't find anything which seems to be profitable. Please inform me when you find a way, since I really wanna make profit with mining :-)
I don't think you can sell your own hashpower on cex.io yet..
of course you can. theres a sell option right beside the buy option lol
Can you explain how it works with selling on cex.io?
Cuz I don't get it. So theoretically I could make acc sell all my hashpower, withdraw all funds - stop hashing. create new account sell again etc..... Making huge profits.
How does cex.io prohibit this behavior?? (To be exact: What do you have to do in order to sell and what are the penaltyes if you fail to deliver the sold hash rate?)