It would be best if you'll click the chart and blow it up to its full size. It's fairly huge and it's fun to look at.
This chart was produced last year in NFTRH as MACD was rounding into a topping situation. What I found interesting was that in the last two instances (Humps 1 & 2) a down-triggered monthly MACD served to drop SPX to the EMA 20, providing the refreshment that gave fuel to the dynamic final upside for the stock market as the ultimate down-trigger and liquidation came well over a year later and from a much higher price.
What is different this time is that price has not done squat (save for the hard stab down during last October's flash correction and reversal), doing all it can do to touch the EMA 10 while MACD makes a stronger looking initial bearish signal than it did on the two previous cycles.
The way I interpret it is that in resisting any price destruction while MACD continues to roll it is probably a good idea to view 2000 and 2007 as cool comps but to realize this thing, built by will of man (and woman) per the chart below, is its own animal fully capable of attaining its targets, which once seemed ridiculous, or imploding for a test of major support or worse.
Humps 1 & 2 were attended by at least some semblance of monetary stewardship. Hump #3? Not so much.
So our post concludes, hey SPX can either rise a long way or drop a long way. Sounds about right because we are in uncharted territory. But as it stands now, that is an ugly looking MACD.