Roll Yield

A futures position has a finite life, so an investor who wants continuous exposure must periodically close the contract nearing expiry and open a position in a later-dated contract. The economic result of that exchange depends entirely on the price relationship between the two contracts at the moment of the roll. A long investor sells the expiring contract at its price and buys the deferred contract at its price; if the deferred contract is cheaper, the same notional exposure is re-established at a lower entry price, which is favourable. If the deferred contract is more expensive, fewer contracts are obtained for the same capital, or the position is re-established at a higher entry price, which is unfavourable.

Expressed in words, the roll return over one cycle is the price of the contract being sold minus the price of the contract being bought, divided by the price being sold. Because the near contract converges toward spot as expiry approaches, a downward-sloping curve mechanically pulls the deferred contract up toward spot over time, and an upward-sloping curve mechanically pulls it down. Short positions experience the mirror image of these outcomes.

At Level I it is standard to decompose the total return of a fully collateralised long futures position into three parts: the change in the spot price of the underlying, the roll return earned or paid as contracts are replaced, and the yield earned on the cash collateral posted against the position. Only the first component reflects a directional view on the commodity or asset itself; the second is a structural feature of the curve and the third is essentially a money-market return.

This decomposition explains why a futures-based product and the spot price of the same underlying can diverge substantially over long horizons. Steep contango can absorb a large portion of a favourable spot move, while sustained backwardation can deliver a positive return even when spot prices are flat. Candidates should be able to reason in both directions: a negative roll component does not determine the sign of total return, and a positive one does not guarantee a profit if spot falls.

The slope that produces roll yield is not arbitrary. Under the cost-of-carry framework, a futures price reflects the spot price plus financing and storage costs, less the convenience yield that accrues to holders of the physical good. When financing and storage dominate, the curve slopes upward and deferred contracts trade above nearby ones. When immediate physical availability is highly valued, typically during supply disruptions or inventory shortages, the convenience yield dominates and the curve inverts.

Market structure reinforces this. Producers seeking to hedge forward output exert downward pressure on deferred prices, while the insurance-theory view holds that speculators must be compensated for absorbing hedging demand. Roll yield is therefore best understood as payment for supplying that service and for bearing inventory and financing conditions, rather than as an anomaly. It appears most visibly in energy, agricultural and industrial metals markets, and also in VIX futures, where persistent upward slope has historically penalised long volatility positions.

Expect to compute a one-period roll return from two quoted contract prices, to assign the correct sign for both long and short positions, and to combine the roll component with spot and collateral returns to obtain total return. Questions frequently test whether a stated curve shape helps or hurts a specified position, and whether an observed divergence between a fund's performance and the spot price is attributable to the curve rather than to fees or tracking error.

Beyond calculation, the concept supports qualitative judgements. Index providers manage roll exposure through calendar rules, laddered maturities and optimised roll schedules, and commodity index returns are commonly reported on an excess-return basis that embeds this effect. Being able to explain why a long-only front-month strategy is structurally exposed to curve shape, and how deferred or spread positioning mitigates that exposure, is the practical payoff.