I crunched some numbers on the profit of GTX 1070, 1070ti and 1080 average hash rate at a price of $0.093 watt.
At each graphics cards average hash rate given the possibility of BTC dropping to $1000, the GTX 1080 and 1080ti are the only cards that will turn a profit at .093 cents per watt. They will return about $0.11 profit after the cost $0.29 to run.
A GTX 1080 cost $550+ that doesnt include the other hardware needed to run the GPU. That means it will take over 5000 days to get your ROI, return on investment.
TLDR: My hypothesis based on this observation is, if BTC drops below $1000 threshold Alt coin mining will become nothing more than a hobby and most Alt coin markets will die. Leaving mostly Proof of Stake Alt coins. These are interesting times.
Max drop will be 6000, no chance to go any lower. But a strategy would be to sell BTC and buy early ICOs at whitepaper state as DIW which I support in my signature. When the whales return and new people start reinvest their money, will invest to new ICOs with solid projects, DIW for ex and Trade.io.
This ICOs will have huge hype, mark my words. x10 the min and x100 in the first 6 months