Here I am trying to understand the firm option expiration cycle:
When I read Investopedia, it says:
Most of stock options are on one of three expiration cycles, which consists of one month per quarter:
1) January cycle: Jan, Apr, July, Oct
2) February cycle: Feb, May, Aug, Nov
3) March cycle: Mar, June, Sept, Dec
With single stock options, a given strike price that once seemed valuable can quickly become obsolete. For this reason, single stock options are on regular expiration cycles.
The above paragraph seems to suggest that for a firm, its options only have four expiration months each year. However, when I check the OptionMetrics database, I found that nearly all SP500 firms have 12 expiration months each year.
Questions:
- How should I understand the firms' option expiration cycle?
- How could I identify which cycle the firm is on?