The underlying, when describing the terms of a future, refers to what?

A futures contract is a standardised agreement to buy or sell an item at a specified future date at a price agreed today. The underlying is the item whose value the futures contract references. Depending on the contract, the underlying can be a physical commodity such as oil or wheat, a financial instrument such as a government bond, an equity index, a currency, or an interest rate instrument. The contract’s price moves as market expectations about the value of that underlying change. The expiry date is a term of the contract, but it is not the underlying. The futures price is the quoted contract price, which is derived from the underlying’s expected value, funding, income, and convenience yield or storage where relevant. The difference between the spot price of the underlying and the futures price is commonly referred to as the basis, not the underlying. CISI exam questions typically focus on ensuring candidates can distinguish the referenced asset from contract terms such as expiry and pricing measures. Therefore, the underlying refers to the asset that the future is based on.