For those that don’t know, you can trade $SPX options from 3am to 9:15am ET weekday mornings, and also from 4p to 4:15p after the market closes. You may need to contact your broker to set up this ability.
What I wasn’t sure about was Monthly expiration options, which stop trading at Thursday’s close but whose settlement price is set after Friday’s open. I just confirmed you CAN trade these until 4:15pm on Thursdays (I closed a 1-lot 1975/1950 put spread that expires in the morning for .10 at 4:05pm)
Options Bistro 