NEO may correspond with this question, not only by the future volume of the market, but also by the possibilities imposed for this currency.
but NEO is not the only one that maybe can replace Ethereum in popularidade, like this: Waves, EOS, Qtum, Stratis, may match the demand, though i believe nothing will beat Ethereum.
I think that with time the third will be EOS in many respects, if the team does everything that it promises, then this coin certainly will be very high!