Only about 10% of USD physically exists: https://www.quora.com/How-much-US-currency-physically-exists-What-percentage-of-the-US-money-only-exists-as-data-on-ban

Only about 10% of USD physically exists: https://www.quora.com/How-much-US-currency-physically-exists-What-percentage-of-the-US-money-only-exists-as-data-on-banks-computers https://www.quora.com/How-much-US-currency-physically-exists... 'M0' is cash. 'M1' are bytes in bank computers. It's really not a big mental leap from USD that doesn't physically exist (which is 90% of USD) to crypto which doesn't physically exist.