$400 plus when?
I do not think the price of bitcoins will ever fall back to $400 ever again. It has passed that stage a short while ago, we are looking forward to a stable price of $800 in 2020.
I am agree with you, that bitcoin would not be under $400 at least. In this time bitcoin faces the up and down, but instead of these crises bitcoin have maintain his position. So it has a clear mean that bitcoin never under $400, even his downing period.