it's clear bitcoin's market dominance should return to 75 percent of the entire space.
I actually see a 150 percent potential upside in bitcoin for 2018.
Why? Well, BTC is still dominant by it's biggest user base and the biggest industry. Still, it faces a challenge in scaling up for wider use.
Bitcoin now can't handle more than six or seven (or, with the "Segregated Witness" protocol upgrade, it's 12 to 14) transactions a second. Compare that with credit cards, which involve thousands of transactions per second, so the criticism about bitcoin's ability to be useful at larger scales is understandable.
The scalability challenge results in high fees as well.
Exciting projects such as those could cause a significant spike in BTC. I would dare say in the realm of 60 to 70 percent with the potential upside of 100 percent — and maybe even more.
RE: Ethereum (ETH): Breakout! Will Bitcoin Follow Ethereum?