The same miners who can't cash out will decide to shut down knowing they'll be mining those coins at < 800k difficulty if they take a break. We've seen this with alt chains -- when it looks like the next difficulty adjustment is severe enough there is a negative feedback loop in computing power. The ones left (free power miners) mine at a disadvantage for a disproportionately long time.
The risk for bitcoin price is a larger % of miners may decide to sell some knowing they'll mine back more coins, cheaper. Going from 15-20% of miners selling their stash to even 30% would be horrific. If I estimate my cost basis to make a bitcoin just went from $2.80 to $.90 I'll have no problems dumping at $2.
If I see a 75% drop in hashing power that'd be my confirmation of a bottom. I will at that point switch strategy from bear to neutral and ready to go bull.
Are you sure? $0.90 is bottom? Please reconsider your decision of dumping at $2.