Starting Aug 15, the CBOE will have Monday weekly options in the SPX. Looks like they are well on their way to daily expirations. So now we have, Monday, Wednesday, Friday and end of the month expirations in the SPX, in addition to regular expirations.
http://ir.cboe.com/press-releases/2016/07-11-2016-193925310.aspx
http://ir.cboe.com/press-releases/2016/07-11-2016-193925310.aspx
