Is there a useful signal in the dollar price? Price of silver? They are all used in hedging bets. Same for BTC, people with a lot of cash are looking for a safe spot while we have the possibility of hyper inflation.
That seems like a lot, but compare it to Apple -- the market cap of just this one company's stock is currently ~2,238bn.
The market cap of gold, US dollars, Euros, etc. are all many times more than Apple. The value of all BTC is a tiny microscopic speck compared to the amount of USD or gold in the world.
This means (among other things) a few small players (with tiny capital relative to, say, the size of all USD) can swing the BTC market either way with a comparatively tiny amount of value moving around.
That would seem to greatly limit BTC's usefulness as any kind of inflation gauge for the broader economy.
600bn is more than gdp of majority of countries.