This is a known fact if the price goes up it will surely go down. What happens if the price of Bitcoin falls to $1000 in 2018, will this be considered as a Worst Case Scenario or something else?
Worst case scenario is the US bans it, causing a huge dip and killing tons of companies who have to liquidate abroad. This however is extremely unlikely since the US is actually pretty damn open about Bitcoin and the jobs it creates, they don't want to lose a silicon valley 2.