Fungibility is the property of a
good or a
commodity whose individual units are capable of mutual substitution. That is, it is the property of essences or
goods which are "capable of being substituted in place of one another." For example, since one ounce of pure
gold is equivalent to any other ounce of pure gold, gold is
fungible. Other fungible commodities include
sweet crude oil, company shares, bonds,
precious metals, and
currencies. Fungibility refers only to the equivalence of each unit of a commodity with other units of the same commodity. Fungibility does not relate to the exchange of one commodity for another different commodity.