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2002issue C101-5

Calendar-spread construction from time decay and implied volatility

An options calendar spread uses two options of the same type and strike with different expiration months. Construction is set by the deferred leg, the movement expected through the near-term window, and the implied-volatility and interest-rate components that stay inside the spread.

  • An options calendar spread pairs the same type and strike across two expiration months so the position can exploit the difference in time value between those months.
  • Long or short is defined by the deferred leg, and a long calendar places strikes near the forecasted trading range of the nearer window when little or no movement is expected through that expiration.
  • Calendar value depends on expected movement between the two expirations and on changes in implied volatility, not only on underlying direction.
  • Call calendars typically price richer than put calendars because longer-dated options are valued off a higher forward, so the interest-rate component must be included in construction.
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Current trackOptions calendar spread30 readings

Two expirations, one strike

A calendar spread uses two options of the same type and strike with different expiration months so the position can exploit the difference in time value between those months.

Whether a calendar is called long or short is defined by the deferred leg. A long deferred option makes a long calendar, and a short deferred option makes a short calendar.

How the near-month window is set

A long calendar is constructed when little or no movement is expected through the near-term expiration, with strikes placed near the forecasted trading range of that nearer window.

A short calendar is constructed for extreme volatility during the near-term option's life and reaches its most favorable payoff when price moves sharply away from the shared strike.

Value beyond underlying direction

Calendar value is not just underlying direction. It also depends on expected movement between the two expirations and on changes in implied volatility.

If the underlying stays near the strike through the near-term expiration, faster decay of the shorter option can widen a long calendar. A large move away from the strike can shrink that value and turn the structure into a loss.

Strike character and the interest-rate component

Relative to the strike, a long calendar takes on bullish character when price is below the strike and bearish character when price is above it, because maximum value occurs when price finishes at the strike.

Call calendars typically price richer than put calendars because longer-dated options are valued off a higher forward, but the interest-rate component remains embedded in the spread and must be included in construction.

Educational research material, not investment advice. Historical source context does not establish present-day performance.
4 of 21 in the Options calendar spread track
20031-4 pp.Next on Options calendar spreadCalendar ratio backspread construction for range and breakout regimesThe overlay sells fewer shorter-dated options and buys more longer-dated options, combining a ratio backspread with a diagonal calendar.
All readings on this track · 21 readings
  1. 1994Competing-bid calendar spreads and implied volatility
  2. 2001Calendar spreads as range overlays with wing repairs
  3. 2002Covered-call premium budgets and calendar-style rolls
  4. 2002Calendar-spread construction from time decay and implied volatility
  5. 2003Calendar ratio backspread construction for range and breakout regimes
  6. 2005Read the implied-volatility regime before calendar-spread assignment
  7. 2005Constructing calendars and straddles around implied volatility
  8. 2005Short option coverage through calendars, rolls, and expiration
  9. 2006Calendar spread expiration, assignment and time skew
  10. 2008The two clocks that close a calendar or a stock-plus-put
  11. 2010Cheap back-month implied volatility is a regime question, not a shopping rule
  12. 2010Calendar-spread assignment as a volatility regime shift
  13. 2010Uncapped collar overlays and earnings-week short calendars
  14. 2011Sequencing verticals, straddles, and calendars as construction tests
  15. 2012Executing conversion and ratio calendar option packages
  16. 2015Near-expiry options on new-crop grain futures
  17. 2018Calendar spreads as range and volatility regime trades
  18. 2019A directional put calendar after a failed resistance breakout
  19. 2019Sizing short-option risk with calendar puts
  20. 2019Limited-risk reversal construction
  21. 2020Covered-call writing versus a calendar call diagonal
By fieldOptions and volatility435 readingsBy year2002145 readings
All 30 readings tagged Options calendar spread
Also on Options calendar spread5 readings
1994Competing-bid calendar spreads and implied volatility2001Calendar spreads as range overlays with wing repairs2001Straddles, strangles, and calendars in an index portfolio context2002Calendar income from volatility skew and time stops2002Covered-call premium budgets and calendar-style rolls