According to Mark Johnson, in Quora, "It is possible that Ethereums price will increase after the EtherZero (ETZ) hard fork on the 19th of January"
What do you think?
This could be possible going by experience with bitcoin. However, it think the price will first go down a little, before rising once again. The good thing is that ethereum is the most stable cryptocurrency in recent history, so the price would not go down much.