Here is an hourly chart showing day session e-mini trading. After yesterday's close I had a chance to reevaluate the market's action. The last hour break now looks like a clearly defined supply shock (blue oval and arrow). As such it should not be significantly retraced, and I think the 1080 level will act as resistance for the rest of the move down.
How low will we go? During the move up from the early July low at 866 there have been three significant breaks of 40, 47, and 63 points. The average is 50 points. A break of this size from the 1099 electronic high would carry the market down to 1049 (purple rectangle). I expect this down move to last a week or so. By the time the low develops I think the rising lower channel line (green dashes) will have moved up to also provide support near 1050.
I think this initial break will find initial support in the 1060-65 range from which zone a rally to 1080 or so should develop. After that the final break to 1050 or so becomes likely. (purple arrows).