I say bitcoin is not fiat currency. Fiat requires a government decree forcing usage of said currency by law. Bitcoin has none of that.
Some people incorrectly refer to bitcoin as fiat currency because nothing "backs it". I say, it needs no backing because like gold it has intrinsic properties that give it value as money, in its purest sense. Idiots will tell you that no, only the us dollar is money, which is a untrue. The USD is fiat currency, while gold and silver are money. Some other commodities have all the properties of money
, but due to their "newness" are not recognized as money. Those are palladium, platinum, and maybe, bitcoin.
Among the major properties of a money are that it can serve as (1) a Numéraire, (2) a means of exchange, (3) a store of value, and (4) a source of liquidity. Among the lesser properties are that it should be easy to transport and identify, it should be durable, easily divisible, hard to counterfeit and easy to store. A possibly desirable property is that it is an anonymous "bearer instrument," but the price of anonymity is that it is hard to recover if it is stolen.