What generally happens when mining becomes unproffitable is the miners themselves refuse to sell bitcoins at a loss.
This drives up the price of bitcoin.
Then more miners come in when profitability increases.
So on and so forth.
There is generally a 3 month delay in the shifting of the bitcoin price,
It happened when the reward halved. It happened when difficulty increased when ASICs arrived on there scene.
Believe me guys, it'll happen again. SO INVEST ALL YOUR SPARE CASH IN BITCOINS! NOW!!
![Grin](https://bitcointalk.org/Smileys/default/grin.gif)
That's quite interesting. I wonder how far this is true. The total amount of mined bitcoins is very small in comparison with the total amount of bitcoins in circulation. If most people hold bitcoin, then most bitcoins on the market will be from these miners, the greater this effect. If prices go up, people that are willing to sell bitcoins at a slightly higher price come in the market and this 'smoothens' the price.