The interchangeability which characterizes a futures contract. More precisely, futures contracts for the same commodity and delivery month and which also trade on the same market are deemed mutually substitutional due to their standardized specifications in terms of quality, quantity, delivery date, and delivery locations.

In more general words, fungibility implies the ability to substitute one unit of a financial instrument for another unit thereof. Notwithstanding, in trading, fungibility usually refers to the ability to purchase or sell the same financial instrument on a different exchange with the same monetary effect.