Thanks for this assessment! Another factor to consider are tax implications. I expect more people to cash out to fiat at the beginning of the year in order to defer taxes until 2019. As a result, the price might trend further downward.
Also, there are alot of new investors. Some might start to sell their bitcoin since it's been somewhat of a prolonged period where bitcoin has pretty much been sideways (not hitting ATH on a weekly basis). With this in mind, some might panic sell if we see a significant drop.