Note: EOM options expire on the last business day of the month. Looking for Year, month when they came into existence! Nevermind! Found it. July 2014!
Yes! For example, examine the January 31, 2017 SPX series. This is last trading day of the month, and occurs on Tuesday, which is one of the EOM options! These are infrequent, since we now have the Monday, Wednesday, and Friday expirations, so they only seem odd when they occur on Tuesday or Thursday, which occurs on Jan 31, 2017 (first occurrence for a while). Difference being the expiration day (not Mon PM, Wed PM, Fri PM, or Fri AM) Can be Tue PM or Thur PM.
Hmmmm interesting. Do you have a bloomberg ticker or an URL ? I trade weekly options all the time because of the huge theta price mismatch and that would seem like a similar instrument.
Same OPRA coding as the Weeklies: Here is a PUT opra: SPXW170131P2175 URL from CBOE from the initial launch: "http://www.cboeoptionshub.com/2014/05/29/new-sp-500-end-month-options-launch-july/" I don't have access to Bloomberg, so am unfamiliar with that! I primarily use TOS.