Contango and backwardation describe how futures prices differ across delivery dates. In contango, a later contract trades above a nearer contract. In backwardation, the nearer contract trades above the later one. For a calendar spread trader, that relationship matters more than whether the commodity itself is rising or falling.
The trading question is not simply “Which shape does the curve have?” It is “How will the price difference between these two contracts change?” The broader mechanics of buying one expiry and selling another are covered in our guide to futures calendar spreads. Here, the focus is on reading the curve, choosing the correct trade direction and separating spread profits from roll yield.
What Contango and Backwardation Describe
A futures curve plots contract prices against their delivery or settlement dates at one point in time. It is not a chart showing how one contract has performed over several months.
Contango means later delivery is priced higher; backwardation means nearer delivery is priced higher. These relationships apply to both physically delivered and cash settled futures, as set out in the London Metal Exchange’s explanation of forward curves.
The following hypothetical prices show the difference. All prices use the same units and represent two maturities of the same product.
| Curve shape | Nearby price | Deferred price | Nearby minus deferred |
|---|---|---|---|
| Contango | $70 | $72 | −$2 |
| Flat | $70 | $70 | $0 |
| Backwardation | $72 | $70 | +$2 |
Check the subtraction order before interpreting a quote
Throughout this article:
Calendar spread = nearby futures price − deferred futures price
Under this convention, a negative spread indicates contango between the selected contracts. A positive spread indicates backwardation. A move from −$2 to −$1 is an increase in the quoted spread, even though the gap between the two outright prices has narrowed.
That distinction makes phrases such as “the spread widened” surprisingly unhelpful without context. State the contract months, subtraction order and starting and ending values. A minus sign is small; the trading error it can cause is not.
Also distinguish the spot comparison from the calendar comparison. A futures contract’s premium to spot and the difference between two futures maturities are related measurements, but they are not interchangeable when the curve changes slope.
Why Commodity Curves Take These Shapes
Contango and the cost of holding inventory
Holding a physical commodity can involve financing, storage and insurance costs. A premium for later delivery can compensate inventory owners for carrying material forward. Contango therefore does not, by itself, mean traders expect the cash price to rise.
Backwardation and the value of having supply now
Immediate access to material can also have value. A manufacturer may prefer inventory on hand to a promise of delivery later, particularly when supplies are tight. This benefit is called convenience yield. When it outweighs carrying costs, it can help explain backwardation.
As expiry approaches, a futures contract converges toward its relevant spot or settlement reference. That reference is not necessarily the spot price observed when the trade began. These relationships between carrying costs, convenience yield and convergence are covered in CME Group’s explanation of contango and backwardation.
For analysis, ask what the deferred premium is compensating holders for, or what makes prompt supply more valuable. The curve label identifies the relationship; it does not explain every reason behind it.
How Curve Changes Produce Calendar Spread Profits
Using nearby minus deferred, buying the spread means buying the nearby contract and selling the deferred contract in matching quantities. Selling the spread means taking the opposite position.
For two matching contracts with the same multiplier:
Long spread profit or loss = (closing spread − opening spread) × contract multiplier × number of spreads
This calculation excludes commissions, exchange fees and execution costs. It applies to the stated long nearby, short deferred position, not automatically to every platform’s “buy spread” instruction.
A profitable trade that stays in contango
Assume a hypothetical commodity future is quoted in dollars per unit, with 1,000 units per contract. The nearby contract trades at $70 and the deferred contract at $72, producing a spread of −$2.
A trader buys one nearby contract and sells one deferred contract. Later, the nearby contract reaches $73 and the deferred contract reaches $74. The spread is now −$1.
The nearby long gains $3 per unit, or $3,000. The deferred short loses $2 per unit, or $2,000. The combined position gains $1,000 before costs.
The market remains in contango. No switch to backwardation was required. The trader profited because the nearby contract strengthened relative to the deferred contract.
A losing trade despite rising commodity prices
Keep the same opening prices, but change the closing prices to $73 nearby and $76 deferred. Both contracts have risen, yet the spread has fallen from −$2 to −$3.
The nearby long gains $3,000, while the deferred short loses $4,000. The spread position loses $1,000 before costs.
This is why an outright bullish view is not enough to justify buying a nearby versus deferred spread. “Prices will rise” and “the nearby contract will outperform” are different forecasts.
The reverse position, short nearby and long deferred, would profit from that same spread decline. Neither direction is automatically correct because the starting curve is in contango.
Backwardation is not a profit guarantee either
Suppose a nearby minus deferred spread starts at +$2 and falls to +$0.50. A long spread loses $1.50 per unit even though the selected contracts remain backwardated.
The useful distinction is between the level of the spread and its change. Contango and backwardation describe the level. Your position earns or loses money through changes from its entry price.
Seasonality Can Create More Than One Curve Shape
A curve does not have to slope consistently upward or downward. Different delivery months can face different supply, demand and storage conditions.
Natural gas provides a useful example. Winter heating demand, summer electricity demand and the amount placed into storage can affect different parts of the curve. The U.S. Energy Information Administration’s research on natural gas price drivers examines how weather, inventories and expected winter requirements interact with spot and futures prices.
Consider a hypothetical natural gas curve with January at $4.20, April at $3.20 and July at $3.60 per unit. January versus April is backwardated. April versus July is in contango. Calling the entire curve “backwardated” would conceal the relationship relevant to the April/July trade.
Contract selection therefore belongs inside the trading thesis. A view about winter scarcity should identify which winter month is expected to strengthen, relative to which other month, and why.
Historical comparisons should also match the seasonal pair and its stage of life. Comparing an approaching winter/spring spread with a summer pair can mix different economic exposures. Even for the same pair, compare observations taken at a similar distance from expiry before treating an old spread level as a useful benchmark.
Convergence Does Not Force a Calendar Spread to Zero
Convergence concerns a contract and its own settlement reference. It does not require two contracts with different expiry dates to become equal before the earlier one expires.
When the nearby contract reaches expiry, the deferred contract still represents a later delivery period. A price difference can remain because the two dates represent different economic conditions.
In the earlier hypothetical example, suppose the nearby contract settles at $73 while the deferred contract remains at $74. The nearby contract has reached settlement, but the calendar spread is still −$1.
A trade based only on “the two prices must meet” therefore starts with the wrong assumption. Write down which relationship should converge and which relationship the position actually trades. Those may not be the same thing.
Roll Yield Is Not the Same as Calendar Spread Profit
Rolling a long futures position means closing the nearer contract and opening a later one. In contango, the replacement contract has a higher quoted price. In backwardation, it has a lower quoted price.
That gap does not itself create an immediate trading loss or gain. The contracts are different instruments. Roll yield reflects the relationship between futures returns and spot returns over time, rather than a cash windfall or penalty generated at the moment of switching contracts. This distinction is demonstrated in the research paper Deconstructing Futures Returns: The Role of Roll Yield, hosted by CME Group.
Suppose a trader buys a nearby future at $78 and closes it at $80. The position has gained $2 per unit before costs. Opening a deferred future at $82 does not erase that gain. Subsequent profit or loss on the replacement position is measured from its own entry price.
Persistent contango can create a drag relative to spot exposure as contracts age, while persistent backwardation can provide a benefit. Neither determines total returns on its own.
A calendar spread trade is different again: both legs remain open together, and the trader is exposed to the changing difference between them.
How to Assess a Contango or Backwardation Trade
Write the expected relative move
Replace “contango should disappear” with a testable statement: “I expect the nearby minus deferred spread to rise from −$2 to −$1 because prompt availability will tighten relative to later supply.”
Then write the opposite case. What development would make the deferred contract outperform instead? If the explanation works equally well for either outcome, it needs more work.
Separate curve analysis from execution
A calculated spread based on two displayed prices is not necessarily an executable price for the intended quantity. Assess the available spread order, the prices needed to trade both legs and the size available at those prices.
Our guide to order book depth and the cost of large trades covers why displayed quotes may not support the full order. For a calendar spread, allow for execution costs on entry and exit rather than treating the theoretical price difference as money already earned.
Set an exit condition in spread terms
A practical trade plan should record:
- The exact contracts, quantities and subtraction order.
- The entry spread and the expected change.
- The spread level or market development that invalidates the thesis.
- The latest acceptable exit date before expiry or delivery obligations become relevant.
Keep monitoring the actual contract pair. Substituting a continuous front contract chart partway through the analysis changes the instrument being measured.
Lower Margin Does Not Mean a Capped Loss
Do not treat the margin deposit as the maximum amount at risk. Futures losses in an individual account can exceed the initial margin, requiring further funds. The CFTC’s guidance on futures contractual obligations makes that funding responsibility explicit.
Translate adverse spread moves into money before sizing the position. With the hypothetical 1,000 unit multiplier used earlier, a $0.50 adverse move costs $500 per spread. Ten spreads turn that into $5,000 before costs. The arithmetic does not become gentler because one leg offsets part of the other.
Assess the cash needed to withstand an adverse move separately from the amount needed to open the position. Our guide to futures spread margin and risk covers that distinction in more detail.
Contango and backwardation are useful descriptions, not automatic trading instructions. A sound calendar spread thesis identifies the two maturities, explains why their relationship should change and measures the loss if that expectation is wrong. The curve is a snapshot, it is not a promise.