The (RTH closing basis only) rule is that if SPX breaks back over the 5DMA after a decline of more than 2%, then SPX must close at or over the 5DMA on the following two days to avoid a fast retest of the low just made. That retest will usually result in a lower low and I have found no exceptions to this rule as far back as the start of 2007, which is as far as I have looked.
In effect this means if bulls fail to close SPX over the 5DMA today or tomorrow, then the 2067.91 low will very likely be retested this week, and likely broken at that test. Stan has a possible scenario back into the 2040s if that happens and was talking about that in his post last night. You can see that here: SPX 5DMA chart:
Bulls need to hold the 5DMA at the close today. That closed yesterday at 2092 and will most likely close a bit lower today. Intraday I'd be looking for support in the 2087 area and the chances of a bullish resolution for today will be considerably lower if intraday support isn't found there.