The recent collapse of FTX got me thinking about the ways that crypto is similar (and dissimilar) to classic get-rich-quick schemes. There’s the suggestion that Sam Bankman Fried was running a ponzi scheme. The full details will I am sure emerge in time.
During the Middle Ages, the "true letter" or "holy letter" became popular with the literate classes. These letters all purported to have magical origins wtih circuitous provenances, and they read a bit like chain letters. So the phenomenon might be as old as writing. If Irving Finkel turns up a chain letter across the Oxus, Indus, and Mesopotamian valleys, I won't be surprised.
Everything old is new again.