one indicator I talked about briefly on the weekend was the DMI and ADX indicator, which you see at the bottom of the daily SPX. This doesn't happen often so it's rare, it only happens when you have a strong momentum run up when the ADX continues to expand and expand and get into the mid 60's, and the DMI is trending up. 

Here's an example the last time we had that in early 2019 Jan.  during that time the ADX got up to 73 at its peak. Currently the ADX is 66.2 so it's high however it can easily keep going. Notice on the 2019 Jan ADX expansion you started to have the +DI part of the indicator (cyan line) sloping down. However on our current time frame this +DI indicator is still sloping strongly, thus I could easily see this push higher still if it wanted to like another week or so

anyway just pointing some observations out.  To see that ADX indicator expansion is rare on the SPX daily, it only happens in those strong trending conditions, sometimes where you get a blow off top afterwards