The thinking behind it is based on the halving of rewards and the stock to flow model. https://bitblogger.org/demystifying-bitcoins-remarkably-accu...

If you follow that reason then it's rational that there are crashes after peaks (cashing out), and it's still rational that it will keep rising to a point that it reaches its true value (whatever that is).

The peaks and troughs will flatten out as that happens.

Could well all be wrong. But so far that seems to be the pattern.