CBOE uses the term "Weeklys" to generally refer to the different types of security options that expire on any Friday other than the third-Friday-of-the-month1.
1. Short Term Option Series Program - These options have a contract duration term of approximately one week and are typically listed on Thursdays to expire on the Friday of the following business week. Settlement is the same as traditional options on the same underlying, e.g., ETF and equity option series are p.m.-settled, OEX option series are p.m.-settled, broad-based index option series in this program are a.m.-settled. For details, product specifications and other information on these options, see http://www.cboe.com/micro/weeklys/ShortTermOptionsSeriesProgram.aspx. See also CBOE Rules 5.5(d) and 24.9(a)(2)(A).
2. End-of-Week Expirations Pilot Program - These options (also referred to as "Week-Ends") may only overlie broad-based indexes and are always p.m.-settled. These options may have a contract duration term of more than a week. For example, an End-of-Week expiration may be listed in May to expire on the last business day of a given week in July. It was noted in Regulatory Circular RG10-112 that on Thursday, December 2, 2010, CBOE commenced trading p.m.-settled End-of-Week SPX Options for expiration on Friday, December 10, 2010. End-of-Week options may be expanded to other classes. For product specifications, see http://www.cboe.com/micro/weeklys/SPXWeeklys.aspx. See also CBOE Rule 24.9(e).
1 If the Exchange is closed on a Friday, option series will expire on the first business day immediately prior to that Friday.
CBOE launched trading in the Extended Trading Hours (ETH) session (from 2:00 a.m. to 8:15 a.m. Central time) on March 9, 2015, for options on the SPX and SPXW (SPX Weeklys and SPX End-of-Month).