It is clear that Bitcoin has two phase behavior, roughly above the mean / median (for ordinary or quantile regressions) trend for a long-term power law fit, and below it. 

The below the median points are the purer power law phase and the above the median points have large shorter term exponential waves (roughly exponential for both rise and fall) superimposed on the underlying fundamental power law behavior.

Storms on a sea. Turbulent layer above laminar flow below. Instability above stability. 

The Yin (bubbles, volatility) and the Yang (power law, stable growth) of Bitcoin.

Thus a mixing of the power law and exponential modes results in lower power law indices and lower R2 values for upper quantiles. The relative strength of these exponential moves has been falling as well as the Bitcoin reservoir (for life) enlarges. 

The chart shows the two phases: a stable phase in green as the purer power law core support and a less stable phase in red with the exponential quasi-periodic bubbles. 

It is the log10 of the residuals after removing a 5.8 index power law; the red and green regions are separately filtered for 26-week moving average and vol window.

The vol of the red Yin zone is nearly 3 x green vol of Yang zone on average. 

The good news is we are just entering the red zone again, so headroom in 2025.