I am kinda worried about one factor - rate of Bitcoin adoption. It seems like adoption slowed down significantly during last year, and sometimes even reverted (Steam is no longer accepting BTC)
Metcalfe's law states that the value of a network increases as the number of users on said network increases. So the number of users we have, affect directly the price  BTC
Adoption is somewhat stagnant - no major company is talking about accepting bitcoin as a payment method - because they know that people are not willing to spend their coins anyway.
I am worried that "hodling' mentality of Bitcoin users, in the end, will be a very big problem and the reason for low BTC adoption.