Futures Calendar Spreads: Define the Legs and Check the Net Result

Name the legs before naming the strategy

A calendar spread uses different maturities of the same futures product with opposite directions. CME's FX calendar-spread FAQ gives exchange examples. Descriptions such as “buy the spread” are incomplete without knowing the venue's quote convention and leg orientation.

For this reference, define spread price as later month minus near month. Define the position as long one later-month contract and short one near-month contract. Under equal multipliers and quantities, that position benefits from an increase in this particular spread price. Reversing the legs reverses the result.

Reconcile the two legs to the spread

Suppose fictional contracts each represent 100 units and are quoted in USD per unit. At entry the near month is 81 and the later month is 83. At exit they are 82 and 85 respectively.

Hypothetical long-later, short-near spread result

Leg	Entry	Exit	P&L before costs
Long later month	83	85	(85 − 83) × 100 = +$200
Short near month	81	82	(81 − 82) × 100 = −$100
Combined	Spread 2	Spread 3	+$100

The spread check is (3 − 2) × 100 = $100. Both outright prices rose, but the later contract rose more. If each had risen by exactly one dollar, the spread would have stayed at two and the paired gross result would have been zero.

This shortcut requires equal quantity and compatible multipliers. If the legs differ, calculate them separately and retain the residual exposure. A visually small quoted spread can still have a substantial money value when multiplied by contract size and quantity.

Execution changes the operational problem

An exchange-listed spread can execute its component legs through the market's spread mechanism. Placing two independent outright orders is a different workflow. One can fill while the other remains pending, leaving temporary directional exposure. CME's simultaneous-execution description for its listed FX spread should not be generalized to every broker interface or copying system.

Record both order acknowledgments, actual quantities, weighted fill prices and remaining orders. Comparing only a net spread price can hide a missing or excess leg. Costs also arise on the transactions in both legs; include the applicable fee schedule rather than assuming one displayed spread means one outright fee.

Maintain the pair through changing dates

Eligible margin offsets can reduce collateral compared with separate outright requirements, but they do not eliminate losses or guarantee a permanent requirement. The broker's account rules and the actual portfolio determine what applies.

As the near month approaches its deadline, the pair needs a deliberate action. If one leg expires or is liquidated, the remaining leg is another exposure. Read notice and last-trade dates alongside the futures-curve guide. Basis is a related but different comparison: it uses a cash or spot reference instead of another futures maturity.