How Equity Option Expiration Cycles Maintain Listed Maturities
Summary
The note explains how exchanges maintain a set of upcoming monthly expirations for listed stock options. Under the described cycle system, each underlying is assigned a quarterly sequence beginning in one of three possible months. As an expiration passes, the exchange lists a new distant month so that several future expiration dates remain available. The IBM example illustrates this process: an option month leaving the listing is replaced by the next month in its assigned cycle, while nearer monthly expirations continue to roll forward.
These cycles are presented as exchange listing conventions rather than pricing rules, and the response emphasizes that the number and timing of listed expirations may change with exchange decisions and customer demand. The examples clarify why months such as March or July appear alongside consecutive near-term months. The excerpt offers a basic historical explanation, not a definitive current calendar; traders should check the applicable exchange’s current listings when selecting a contract.
Key ideas
- Equity options are assigned to quarterly expiration cycles that begin in different months.
- Exchanges introduce new listed expirations as existing contracts expire to keep future maturities available.
- Near-term monthly options can appear alongside later months from the assigned quarterly cycle.
- Listing schedules are exchange conventions and may change, so current listings should be checked.
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Full text
# How should I understand expiration dates? # How should I understand expiration dates? The following is an excerpt from Introduction to the Mathematics of Finance by Roman: > Expiration Dates The last trading day of an option is the third Friday of the expiration month and the option actually expires on the following Saturday. Every stock option is on one of three expiration cycles, which consists of one month per quarter, equally spaced 3 months apart, but starting at different months: 1) January cycle: Jan, Apr, July, Oct 2) February cycle: Feb, May, Aug, Nov 3) March cycle: Mar, June, Sept, Dec If the expiration date for the current month has not passed, then there exist options that trade with expiration dates in the current month, the next month and the following two months of the cycle for that underlying. If the expiration date for the current month has passed, then there exist options that trade for the next month, the month after that and the following two months in the cycle. For example, IBM is on the January cycle. At the beginning of January, there are options that expire in January, February, April and July. Late in January, there are options that expire in February, March, April and July. At the beginning of May, options expire in May, June, July and October. I don't understand the paragraph in bold. Is it a rule for the expiration dates? Would anybody explain the IBM example? I totally don't understand where are those months from. ## Answer by nbbo2 (score 3) https://quant.stackexchange.com/a/27675 Yes, these are rules that the exchange uses to start trading new options as the old ones expire (if no new options are introduced trading will come to a halt...). These rules guarantee that a "reasonable number" (which is subjective, of course) of future expiration dates are in existence at all times. But these rules are not that important (not worth memorizing) and they can change if the Exchange decides they want to offer more (or fewer) options in response to customer demand. My suggestion: don't spend too much effort now on these details... (you can look up the information later if needed). The first example that they give is pretty easy to follow: "For example, IBM is on the January cycle. At the beginning of January, there are options that expire in January, February, April and July. Late in January, there are options that expire in February, March, April and July." What this is saying is "upon expiration of the January 2017 options, the exchange will begin trading IBM options for March 2017", so that as you can see the number of available expiration dates will remain equal to 4. In general these rules determine, upon expiration of an option, if one (or more) new options need to be introduced, and which one(s) it will be.
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This summary was written by Stratmill's research agent from the original; it is not a copy of the source.