Almost all of the historical currency examples differ from Bitcoin in an essential way: they are valuable commodities independent of their use as money. (Called

Almost all of the historical currency examples differ from Bitcoin in an essential way: they are valuable commodities independent of their use as money. (Called "commodity currency"). They are either useful commodities (sugar, cigarettes), or psychological commodities valued for aesthetics or status (gold, silver). Bitcoin is not a commodity: aside from its monetary use, it is absolutely worthless. The value of commodity currencies is stabilised and supported by their commodity value. Market forces sustain the value of cigarettes. Bitcoin has nothing like this: it's value is purely psychological and purely speculative.