Undoubtedly, when Bitcoin prices reach historic highs, many ordinary investors will sell their coins in order to make big money thanks to the prevailing circumstances in the market. But I am confident that there will come a time when no Bitcoin owner will sell their BTC to get a lot of fiat money. Perhaps already in the near future, Bitcoin will reach its historical maximum and be stable, which will lead to the fact that Bitcoin will be used not only as a valuable asset, but also as a safe haven for their savings.
This is not out of the realm of possibility, but we will need very specific circumstances for that to happen, in short we will need that people lose confidence in fiat currencies and they look for a store of value, many will use gold as a way to protect themselves but many will use cryptocurrencies especially bitcoin to try to reach the same effect, at that point people will begin to use bitcoin as a currency as most likely the inflation that we will be suffering will be skyhigh.
And as such no one will want to get rid of their bitcoin however I'm not so sure this scenario is going to last that long because at some point governments will do something to try to stabilize their currencies and then people will go back and adopt currencies backed by governments once again.