Yet he argues that new forms of cash often emerge by accident from unexpected places, rather than by design, as is the case with cryptocurrencies. For this reason, I would have liked a chapter on underground and https://wallstreethack.com informal currencies. These shadow monies too are social, unofficial and come to the fore where the mainstream system fails. Deriving from the Latin word fiducia, to trust, fiduciary money works on the promise and trust that it will be exchanged for fiat or commodity money by the issuer . People are not required to take it as a form of payment because it is not a government-ordered legal tender. In economics, money is simply something generally accepted as a medium of exchange for goods and services (Merriam-Webster).