I have been mining off and on using Hashnest. Basically you buy hashpower using bitcoin. The current price is around 0.00007800 btc per hash power. You go on the exchange and put in your own bid for hashpower. When you exit, you put up your own offer. It’s just like trading bitcoin against USD. Except here the trade is BTC to hashpower.

It’s fairly easy to make a profit (in BTC) by trading btc for hashpower. The price rises or falls all the time. Buying hashpower is like buying an Antminer S9, except you may only own a fraction of the machine and can often sell it for more than you paid.

In terms of return you currently make around 7.5% per month after costs, paid in bitcoin. In other words if you invest 1 bitcoin, you should, after one month have 1.075 btc. It does not matter what the price of btc is,

If the price of bitcoin rises, then so should the price of hashpower. So for example you could invest 1 bitcoin, and maybe sell your hashpower for 2 bitcoins later. Of course the opposite would be true if the price of bitcoin falls.