SPX breaking the 21 day moving average

SPX is trading below the 21 day moving average as of writing. We haven't seen the SPX futs below it since late May. 4400 is the short term must hold. This is the lower part of the big trend channel that has been in place since March lows. If that is broken, 4360 should come into play. 500 day is currently at 4308. So far this is just a much needed mini pullback, but does it grow?