Bubbles or Regime-Switching in Gold and Bitcoin?

I don’t have the answer, but the two series do make quite a picture (all in logs since five years ago):

Figure 1: Log difference from 6/29/2021 in bitcoin (green, left scale), in gold (blue, right scale). Source: TradingEconomics.com.

On equities, note the Nasdaq is down, while the SP500 is below peak, but not yet falling drastically.

Figure 2: Log difference from 6/29/2021 in Nasdaq (green), in SP500 (blue). Source: TradingEconomics.com.

For economists, a bubble occurs when the price deviates from the present discounted value of the returns from an asset (including being able to evade regulations, taxation, etc.); that is when the discounted expected price in the infinite future does not equal zero. There are other looser descriptions of bubbles. You could call those Shillerian “fads”, etc.

Anyway, I’m going to say that some of these asset prices are looking like they’re coming down, for whatever reason.