I remember earlier in the year Crypto Man Ran (https://twitter.com/cryptomanran) made a prediction that by the end of 2018 BTC dominance would fall to or below 20%. But like so many other predictions it seems like he's going to be wrong on this one. I fully am expecting BTC Dominance to rise, much higher than current levels. I think we will see it rise to at least 90% dominance before this bear market comes to an end, probably over 95% and maybe as high as 99%. How much needs to bleed out of bitcoin to make that happen?
I think the way this market works is that most people who cash out cash out through bitcoin. They sell their alts for BTC (putting downward pressure on that pairing with BTC, but not really doing anything to effect BTC vs USD in my opinion), then they sell their BTC for fiat, pushing BTC down against the fiat pairing. The problem is almost all alts are a complete and utter scam, and most of the ones that aren't are completely over valued.
I think however, what everyone is missing in all of this, is that nothing has changed with Bitcoin. 2017 created this whole narrative around alt coins, and we had the Bitcoin Cash fork, which should really be considered an insignificant event, but it was sensationalized by the crypto media. Dogecoin processes more payments than Bcash. Satoshi's Vision is still alive in the real bitcoin, we're just facing economic pressures beyond the control of hodlers, because of an over inflated bubble market caused in 2017.
I'm not even shook, Bitcoin maximalism should be on the rise by the end of this bear market. Long live bitcoin!