i don't think that we will be back to 400$ soon as price now is 650$ and we had halving 1 week ago so i am pretty sure that price won't fall down but will rise only
of course the price is not going to come back down, that would be a huge disaster as a lot of people would be sad about the price dropping and they would sell a lot of bitcoins
I think so. The bitcoin shall not drop below $400. The bitcoin has more users and is more useful than before.