Great question.
Another question that will help figure this out is why is Bitcoin so volatile? First cryptocurrency is inherently volatile due to its commodity style supply and demand model coupled with small markets and according to Investipedia, technology is the most volatile sector of trading.
https://www.investopedia.com/financial-edge/0712/the-8-most-volatile-sectors.aspx
With that in mind some of the volatility can be ameliorated with a larger market and the end of proof of work. But it will still be a technology so some volatility will always remain?