Roll yield: what it means for your returns

Why this matters to European investors

Many Europeans encounter roll yield indirectly through commodity funds, ETPs and leveraged products, not necessarily through a direct futures account. The difference between the spot price and the product's return can then come as a surprise.

An oil headline can say the commodity is flat, while the product falls because the futures curve has produced a negative roll return and costs. Conversely, backwardation can cushion losses or amplify gains. That's why you need to read what the product actually owns, not just the name on the label.

A commodity can be unchanged in the spot market while a futures-based fund loses money. The opposite can also happen: the spot price falls, but a favourable futures curve cushions the loss or lifts the total return. The explanation often lies in roll yield.

The term is used a lot, but imprecisely. Some define roll yield as the price difference between the contract that's sold and the one that's bought. Others use it for the gain or loss that arises when a futures contract converges toward spot. To analyse returns correctly, these two observations need to be kept separate.

Why futures have to be rolled

A futures contract has an expiry date. An investor who wants continuous exposure generally can't own the same contract forever. Before liquidity dries up or the delivery process approaches, the old contract is closed and a later contract is opened.

For a long position, a standard roll means:

1. Sell the contract approaching expiry.
2. Buy a contract with later delivery.
3. Keep the desired notional exposure per the fund's or strategy's method.

The process is described in more detail in futures rollover and expiry. Roll yield is about how this continuous exposure is affected by the futures curve and how the contracts develop.

What is roll yield?

Roll yield is the part of the futures return that can be linked to the contract's price changing relative to spot or other maturities as time passes, and to the exposure being periodically moved to a new contract.

A useful, simplified decomposition of collateralised futures returns is:

This is an economic decomposition, not a perfect accounting identity for every product. The definition of "spot return" and "roll return" varies between index providers. Always read the index methodology before comparing two products.

The most common explanation - and why it's incomplete

Assume the front contract is sold at 70 dollars and the next contract is bought at 72. This is often described as an immediate roll loss of 2 dollars. That's pedagogically tempting, but economically incomplete.

In the roll, the investor swaps one instrument for another with a different delivery date. The purchase at 72 doesn't by itself create a 2-dollar loss; the new contract also starts at 72. If the entire curve stays unchanged in shape and spot remains 70, the new contract can gradually fall toward spot as it approaches expiry. It's this negative convergence - not the swap itself - that creates the headwind.

Likewise, buying the next contract cheaper than the old one in backwardation isn't a free gain at the moment of the roll. The potential positive roll yield is realised through later price movement and convergence, provided the curve and spot don't move unfavourably.

Contango and negative roll yield

In contango, more distant futures are normally more expensive than nearer contracts. A long front-month strategy therefore rolls "up" the curve. If the spot price and curve shape are otherwise stable, the more expensive contract tends toward a lower price as time passes. This produces negative roll yield.

Example:

• Spot price: 70 dollars
• Front contract at purchase: 71 dollars
• The contract approaches expiry and falls to 70
• Spot is unchanged

The futures position loses 1 dollar even though spot doesn't move. When the next contract is bought at 72, a new possible convergence period begins.

With persistent, steep contango, repeated rolls can become a large return headwind. The effect is especially visible in commodity products that mechanically hold the nearest contract.

Backwardation and positive roll yield

In backwardation, more distant contracts are normally cheaper than nearer contracts. If spot and curve shape are otherwise stable, a long contract can rise as it approaches the higher spot price. This produces positive roll yield.

Example:

• Spot price: 80 dollars
• Futures bought at 77 dollars
• At expiry, the contract converges toward 80
• Spot is unchanged

The 3-dollar gain comes from convergence. But if spot simultaneously falls to 72, the contract can still end up lower despite the original backwardation. A positive expected roll yield is never a guarantee of a positive total return.

Read the basic explanation in the guide to contango and backwardation.

A complete numerical example

Assume a product invests 10,000 dollars in an oil contract priced at 100 dollars. For simplicity, we ignore the multiplier and assume 100 price units of exposure.

A month later, spot is still 98 dollars, and the contract has converged from 100 to 98. The futures leg has fallen 2 percent. The product sells the contract and buys the next one at 101. The number of units is adjusted so the capital exposure remains roughly 10,000 dollars.

The next month, the new contract converges from 101 to 99, while spot ends at 99. The product loses around 1.98 percent more. Spot is only up from 98 to 99 in the second period, but the futures exposure loses because it started above spot.

What matters isn't that 98 was sold and 101 bought at the same instant. A proper rebalancing preserves roughly the same dollar exposure. The headwind comes from each new contract again starting above spot and then moving down, if the market stays in contango.

How roll yield can be estimated

A simple ex ante measure between two contracts is:

For 70 dollars in the near contract and 72 in the far contract, this comes to roughly −2.86 percent for a long roll. But the figure is only a curve indication. It is not the same as actual future returns.

For contracts with different time between rolls, the measure can be annualised:

where $d$ is the number of days between the relevant maturities. Annualising can produce dramatic numbers on very steep front spreads and shouldn't be interpreted as a stable annual forecast.

An ex post calculation instead looks at the contract's actual price change through the holding period, checked against a chosen spot or price reference. It's more precise historically, but depends on the methodology.

Roll return, roll yield and roll cost

The terms are used interchangeably in market commentary:

• Roll gap: the price difference between the contract sold and the one bought.
• Roll cost: can mean a negative roll gap, transaction cost, or overall carry headwind.
• Roll return: the index provider's measure of return tied to the futures curve.
• Roll yield: the economic contribution from movement along, and rolling of, the curve.

When someone claims a fund has "lost 10 percent on the roll," you should ask which definition, period and index methodology was used.

Spot return is not futures return

Spot is the price of the commodity for immediate delivery. A financial investor can rarely buy the relevant spot commodity without storage, transport, insurance and quality control. An oil futures contract is therefore not a perfect copy of a physical oil position.

For commodity futures, returns typically come from three sources:

1. changes in the general price level
2. curve and convergence
3. the return on cash collateral

In periods of high short-term rates, collateral yield can offset some negative roll yield. A spot chart alone therefore doesn't explain the product's return.

Futures account versus ETF or ETP

Direct futures

A trader chooses the contract month, roll timing and position size themselves. Gains and losses are marked to market daily. The trader can also close before the roll or trade calendar spreads directly.

Futures-based fund or ETP

The product follows an index or published roll method. The investor doesn't necessarily own the physical commodity or a static futures contract. The result is affected by the index's contract selection, roll window, collateral yield, costs and rebalancing.

Two products with "oil" in the name can therefore end up with very different returns. One can roll the front contract every month, while another chooses the contract with the most favourable implied roll, or spreads the exposure over several months.

Leveraged products

Daily leveraged ETPs also have a compounding effect. In volatile sideways markets, returns can be eroded even before roll yield and costs are considered. Roll yield shouldn't be used as a universal explanation for all tracking difference.

The roll method matters a lot

Common methods include:

• a fixed roll from the first to the second contract on set dates
• exposure several months out on the curve
• spreading across several contract months
• an optimised choice based on curve shape or liquidity
• a dynamic roll window to reduce market impact

A strategy further out on the curve can have milder contango, but also a weaker reaction to changes in the spot market. An "optimal roll" can reduce historical cost, but carries model risk and can crowd investors into the same contract.

Why the curve changes before you get to roll

Ex ante roll yield is observed on today's curve. Actual returns are determined by tomorrow's prices. The curve can:

• steepen: the difference between near and far increases
• flatten: the difference shrinks
• shift from contango to backwardation
• move up or down in parallel
• change only one part because of a season or an event

A trader can therefore profit from a long position in a market that started in contango if the price rise more than compensates for the carry. A calendar spread can simultaneously lose even if the direction on the commodity was right.

Inventory and convenience yield

Academic research on commodity futures ties the futures curve and risk premia to physical inventory. When stockpiles are high, convenience yield is often low and contango more likely. When inventories are scarce, the value of owning the commodity now rises, and backwardation becomes more likely.

This is an economic mechanism, not a mechanical trading rule. Official inventory data can lack quality, location or commercial holdings detail. A scarcity that's expected can also already be fully priced in.

Markets where roll yield is especially important

Oil and refined products

Storage cost, terminal capacity, OPEC+, geopolitics and seasonality can make the front curve steep. Front-month products can deviate significantly from spot headlines over time.

Natural gas

Strong seasonality makes a simple month-to-month comparison misleading. Winter contracts can be expensive because they carry cold-weather risk. Roll yield must be assessed against the normal seasonal curve.

Grains

Old and new crop are economically different inventory situations. Harvest can create contango, while low old-crop stock can produce backwardation before the new crop.

Metals

Financing rates and inventory play a large role. For precious metals, physically storable volume is large; for industrial metals, inventory scarcity and delivery location can create sharp front spreads.

Financial futures

Carry also exists in index, currency and interest rate futures, but "roll yield" is most often used in commodity analysis. For equity indices, the basis reflects, among other things, interest rates and expected dividends. The price drop on ex-dividend dates shouldn't be confused with commodity-based convenience yield.

Roll yield for long and short

For a long front-month strategy, backwardation is normally favourable and contango unfavourable, all else equal. For short exposure, the sign flips economically, but the risk isn't symmetric in practice. A physical scarcity shock can produce explosive price increases and sharply negative short returns.

Short ETPs also have their own daily reset and compounding rules. It's insufficient to simply "invert" the expected long roll yield and assume the rest follows automatically.

Common mistakes

Booking the entire roll gap as a same-day loss. The new contract has a new starting price and a different maturity. Assuming contango always produces a negative total return. Spot movement and collateral yield can dominate. Assuming backwardation guarantees a gain. The curve can change and spot can fall sharply. Comparing a fund with a spot headline. The product may follow an entirely different futures index. Ignoring currency. A European-listed product can have dollar exposure with or without currency hedging. Using an annualised front spread as a forecast. It's a snapshot, not a promised annual return. Overlooking fees and tax. The net result is more than just the futures curve.

A checklist before you buy commodity exposure

1. Does the product own the physical commodity, futures, swaps or shares?
2. Which index does it follow?
3. Which contract months can the index hold?
4. When, and over how many days, is the position rolled?
5. Is today's relevant curve in contango or backwardation?
6. How steep is it after annualisation and seasonal adjustment?
7. What is the cost, spread, collateral yield and currency exposure?
8. Does the product have daily leverage or an inverse reset?
9. How large a deviation has the product historically had versus the index?
10. What scenario would invalidate the investment idea?

Conclusion

Roll yield explains why futures-based commodity returns can diverge sharply from the move in the spot market. In persistent contango, a long investor normally faces a headwind; in persistent backwardation, the curve can provide a tailwind. But the roll gap is not an instant loss or a free gain, and the curve shape is never a guarantee.

The right analysis begins with the product's actual contracts and roll rule. Then spot change, convergence, collateral yield and costs are separated. Only once all the parts are visible do you know what the "commodity return" actually consists of.

Capital risk: Futures trading carries a high level of risk and is not suitable for everyone. Losses can exceed deposited capital. This article is general information, not investment advice.

Sources and further reading

• CME Group: What is Contango and Backwardation?
• Gorton and Rouwenhorst: Facts and Fantasies about Commodity Futures
• Gorton, Hayashi and Rouwenhorst: The Fundamentals of Commodity Futures Returns
• Frankfurter and Accomazzo: Term Structure and Roll Yield
• CFTC: Futures Market Basics

Frequently asked questions about roll yield

Short answers on roll yield, contango, backwardation, commodity ETPs, roll methods and actual futures returns.