[sowbug]

Money supply (M0, M1, M2, etc.) is an important concept, no citation needed.

Your quarrel seems be with the broad application of the term "market capitalization." From context, it's clear what people mean, much as it's clear what it means to "dial" a phone number on a phone that doesn't have a dial. Surely there's a better response against digital currencies than stating that Bitcoin's $607B aggregate value isn't technically called a "market cap."

[wpietri]

It is clear what it means: a bunch of grifters are trying to pretend their magic beans are an actual investment like equities are. So they want a big and impressive sounding numbers, especially one that can be easily manipulated by wash trades and the like.