In 5 years, it can become stable than now, i think in one condition if it would be regulated. For my opinion, for somehow Bitcoin must be regulated. Hiwever, the total centralization would kill all key features for what we value cryptocurrency. So I think after 5 years we find the way how to regulated it, but keep its features as well. Otherwise, it remain unstable, And it is popularity would grow slowly as well as an investment in it but not mainstream fastly.