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?
The worst case scenario for Bitcoin? That's a really tough answer to give, as there are several determining factors that could easily spell the end for any crypto currencies. Here are a few that I can think of off of the top of my head.
1.
Regulation: To many regulations can really hinder the blockchains innovation, severely crippling progress for growth, both economically and socially.
2.
Tax: The governments can easily kill crypto simply by taxing it to death. No one would bother with using a useless medium as an investment vehicle.
3.
Adoption: Bitcoin and other cryptos simply take a back seat, as a new medium that's backed by a central authority, one that the common man will trust. Unless crypto becomes easier to use, people will use something else, following the path of least resistance (mediums with simpler interfaces).