I am a novice too when it comes to a lot of things related to bitcoins but I am aware how bitcoins are known to be extremely volatile in nature and as such is expected to go up and down, plateau, or whatever from time to time.  It is known to fluctuate in value especially during the last and first quarter of every year, maybe because of activities in the market too and how users behave. Having said that, I don't see 2018 as bitcoin's year of downfall.  It may bring about a whole new set of challenges because of new coins coming and going and with better playforms but I personally feel that bitcoins will continue to surpass these challenges.  Otherwise, should there be a coin that could be at par with bitcoin this year, I think that's ok and it would not mean downfall right away for bitcoins.  It's too early to predict, I know that, but I agree with most comments here that bitcoin will still remain supreme this year.