5th wave can fail to reach the 3rd wave peak - in the SPX case 1730.
A failure to break above 1730 now that the SP-500 has reached 1721ish will likely send the SP-500 price falling rapidly back down toward were the ending diagonal began at 1560.
The maximum ED target for completion is at 1749. To the up-side a move above 1749 would invalidate the ED count. To the down-side watch for a move below the SP-500 50-day SMA (1679) to signal that the ED is complete.
I am watching the same thing, Today the spx printed 1745 1-18 I am looking for a slight up move on monday to 1647-8 to short. Looking for a test of 1710 with a breakdown targeting 1686. Below that brings your 1600 into target.