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Calendar spread vs. diagonal spread
Understand calendar and diagonal spreads, the decision it supports, and the pricing and execution risks to check before acting
Prepared by Mark · Primary sources below
Direct answer
A calendar spread uses options of the same type and strike with different expirations, while a diagonal spread also changes the strike. Both separate near-term and longer-term options, but the diagonal adds directional and strike-width choices to the term-structure trade. Their value depends on two expirations, potentially different implied volatilities, theta, vega, stock movement, and the price of closing both legs.
Calendar and diagonal spreads: the core structure
A calendar spread uses options of the same type and strike with different expirations, while a diagonal spread also changes the strike. Both separate near-term and longer-term options, but the diagonal adds directional and strike-width choices to the term-structure trade.
Calendar and diagonal spreads: the variables to compare
Their value depends on two expirations, potentially different implied volatilities, theta, vega, stock movement, and the price of closing both legs. Compare the complete position at the near-term expiration instead of applying a simple final-expiration payoff diagram.
Calendar and diagonal spreads: the risk that remains
The short option can be assigned before the long option expires, and the remaining long leg can change the risk after the front expiration. Check dividends, exercise style, liquidity across both maturities, margin treatment, and the exact plan to close or roll the short leg.
Common questions
What does calendar and diagonal spreads help explain?
A calendar spread uses options of the same type and strike with different expirations, while a diagonal spread also changes the strike. Both separate near-term and longer-term options, but the diagonal adds directional and strike-width choices to the term-structure trade.
What should I check before using calendar and diagonal spreads?
Their value depends on two expirations, potentially different implied volatilities, theta, vega, stock movement, and the price of closing both legs. Compare the complete position at the near-term expiration instead of applying a simple final-expiration payoff diagram. The short option can be assigned before the long option expires, and the remaining long leg can change the risk after the front expiration. Check dividends, exercise style, liquidity across both maturities, margin treatment, and the exact plan to close or roll the short leg.
Sources and further reading
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