It's not too challenging for bitcoin because there are worst cases than this and I have read through the bitcoin forum it has dropped like 90% of the original price where it rolled back from $ 32 to $ 2. I think you should be happy with the current situation because it's only ~ 40% drop and it's also the most expensive coin on the blockchain. I'm sure every drop that you see now and so on will look very small to you as an example that I give far more strongly to believe this. All is an intelligence test for Bitcoin, 2018 is not the worst, it can only be better, we have seeing that Bitcoin has strong support at 6k plus, I don't see it going further down, but when it will bounce back is what we are not sure of. Maybe if SEC rules support EFT.