Cryptocurrencies only seem to "work” when prices are going up. On the way down, nothing functions as it should — a trait common to Ponzi schemes throughout history.

In the current market carnage, the exchanges that have promoted digital currencies have a lot to answer for.

Bitcoin, supposedly a store of value and inflation hedge in the eyes of luminaries such as Jack Dorsey or El Salvador’s Nayib Bukele, is failing at both. It’s down about 56% in six months as investors dump it for the traditional fiat money that crypto was supposed to disrupt.