So the bitcoin market cap is currently at $1.8 trillion.
You can compare that to USD M0 which is $5 trillion or EUR M0 which is around €4 trillion.
Not bad for an "extremely inconvenient database".
Slippage yo. Market cap means jack shit if the true order book is thin like a slice of carpaccio.
South Sea Company at its height was worth almost 3x British GDP. Not bad for a company "with negligible business activities"!
Market cap is pretty hypothetical though - if somebody actually tried to liquidate $50bn of bitcoin into fiat money you'd probably send the BTC price to about zero...