Okay, let me come at this from a different direction, but first my apology to the OP for butchering his thread! lol If you traded this short strangle, as described, above, you couldn't realistically use a typical, dollar-value stop-loss because this is a 0DTE trade and premium would be eroding fast all day. But you should still be able to make this trade and then... if price takes out one of your short strikes by X points, that is where you would stop yourself out... by buying back that one short option for whatever the price is, even though it might only be a few cents. So you would lose the X points times 100, but sill keep both premiums collected. Now... if you wanted to limit your loss to $100, you could take the $252 in premium collected, add $100 for the stop, then divide $352/100 and get 3.5 points. So a 3.5 point breach of either short strike would take you out of that one side of the trade. So it's not an unlimited loss scenario unless you aren't paying attention. If that is correct, then it seems a short strangle under this, or a similar, scenario, is a reasonably valid trade idea.
I used to trade ICs and flies in 0DTE SPXW quite a bit. It can be a reasonably decent strat - at least in a less-volatile market. The 0DTE fly is one of the few options trades where I use stops.
Yeah... no. Gaps and spikes - and there are plenty of those as you get toward the close - can and will (if you keep trading long enough) put a serious hurt on you. Trust me on this one: don't trade undefined risk in SPX.
Hey, OP... did you see that warning from @BlueWaterSailor? He is one of a number of options traders around here who really know their stuff. So if you intend to continue selling naked SPX 0DTE options, you might want to give his advice/warning some serious consideration.
Eeek. Much as I appreciate the compliment, I have a long way to go before I'm at the level of competence of the really sharp folks here. I'm careful to only assert things that I have tested myself - i.e., I do my best never to mislead anyone - but unlike @MrMuppet, @destriero, or a couple of others here, I'm not anywhere near what I'd consider "knowing my stuff". Working hard at it, though.
Sorry, didn't mean to embarrass you, and there is still time to delete my post if you want me to. But from what I've read from you in the past, I personally consider you an experienced options trader, and will continue to hold you in high regard.
Stop being so modest. You are embarrassing me, because I talked you up to Baron on our last phone call. Eat your damned delicious cookie and like it!