This box has occurred as soon as the SPX convincingly broke thru the upward trendline from the Dec18 lows when it fell off ATH at 3020.
This pattern is very similar to the boxed in range that was evident between Oct and Nov18, when it was breaking through the upward trendline from the 2009 low, (the start of this huge 10 year bull-run ). The ranging in the previous instance resulted in the plunge to the Dec18 lows. This current ranging could result in a test of the June19 lows and possibly a test of the same Dec18 lows but maybe not before a slight bounce.
The difference between the 2 boxes is that in the first instance the SPX was below the 200 day MA and was using that resistance whilst now it is above the 200 day MA and is using that as a strong support, which suggests that it will attempt to break thru it at 2800.
2800 was the line of resistance throughout 2018 and now it is the support. Will it break thru? I think it will and that is why it is ranging and waiting for an opportune moment to take the plunge.
The reason why the SPX is ranging, is that it has now convincingly broken the Dec18 upward trendline on its way down from ATH at 3020 and is challenging the 200 day MA at 2800, (and the fact that 2800 was the line of resistance for all of 2018) and also; most importantly it is targeting the Dec18 lows with clear intent.