I have been studying trends in MACD, they show up a lot of times in certain patterns, particularly megaphone patterns, or the inverse. Usually these start in one direction, and then when this is broke, the opposite takes place. So convergence is followed by divergence, or vice versa. I also notice there is usually no clean break between the two, but there is a transition where both trends overlap. Contacting the trend line, particularly in an overbought or oversold condition often indicates turns with great accuracy. Note also there are shorter trends within the larger trends, but I will not look at that here.
So with that said, I present the trends in the SP500. There was a convergent trend from the 2009 bottom into about 2014. Then a divergent trend occurred which we are in now. So you will notice the MACD hit that upper trend line at the recent market turn point. I would not have imagined it could get up that high to reach that resistance line again, but it sure did.