ETH is gaining popularity just because of the issues Bitcoins currently having.. like slow transaction, higher fees, etc
once segwit gets activated, then i think it will be difficult for ETH to stay stable with current price
Also ETH have a Scalability problems which probably could solve POS.
But PoS as a method is not secure and we had a security issue before with ETH.
A lot of hacks.
POS could solve scalability ,but will it be secure?
Also after PoS dificulty will be less,so as a price.
Dont forgett that ICO craze is over after SEC regulators come.