I will not say unstoppable. But Bitcoin is really performing well now stable in it's high price that was reached for the past 5 years. But someday, if some negative big factor will come, it will really bring down the price.
the closest is the upcoming fork, I think the bitcoin price will decrease a little because people tried to buy the bitcoin to receive BTG and at which they will sell the bitcoin. It seems like people buying up BTC to get as much Bitcoin Gold from the upcoming fork is playing a huge part in the price increase. However it will reduce slightly and then back to strong growth. $7000 at the end of the year is feasible