To serve as a measure of value, a medium of exchange requires constant inherent value of its own or must be firmly linked to a definite basket of goods and services. Furthermore, constant intrinsic value[dubious ] and stable purchasing power are needed. Gold was long popular as a medium of exchange[dubious ] and store of value because it was inert, meaning it was convenient to move due to even small amounts of gold having a considerable and constant value[dubious ].