I think one of the common reasons for the continued Bitcoin price rise is the positive news about speculations or predictions on the price of Bitcoin in 2018 and/or before the year ends. News headlines, such as, "Bitcoin headed to $100,000 in 2018, says analyst who predicted last year's price rise", "Bitcoin price RISE: Cryptocurrency could top RECORD levels of $50,000 in 2018, says expert", and "Bitcoin could bounce back big-time in 2018: analyst" are gaining 20% or more acceptance rate which I think has contributed to the demand of the cryptocurrency.