Option Expiration – the final trading day that an option contract can be traded. There are significant differences for option expiration across underlying products like ETF and futures, so it is important to know the exact dates.

For example for stocks and ETFs this is usually for a monthly option this the 3rd Friday of every month. For weekly options this usually every Friday. If exchange holidays (such as New Years Day) fall on a usual option expiration Friday, then typically the previous trading day Thursday is used as option expiration.

For futures options their option expiration date does not always have an established pattern for week day OR crucially expiration time. For example Crude oil /CL futures options expire on Wednesday at 14.30CST on same day as oil inventory report. Best advice is to check the cme group website for contract specs which gives exact expiration dates.