I'm going to guess that we have a pretty firm bottom somewhere in the region of what it actually costs to mine one Bitcoin. Anything below that would suggest (at least to me) a loss of confidence not in the market, but in the entire crypto concept.
Unless somehow the entire world production of Bitcoin moves to Venezuela (which doesn't have the electrical infra structure to support such a thing) I'm guessing $4000-ish would represent an absolute bottom, although I don't like words like "absolute," when it comes to markets... people are fickle.