Reverse trend correlation?

You can write a stochastic equation of Y in terms of X if you know the math.

 

IMO, there is no mathematical way to show correlation or causation from your description.

 

https://www.mrci.com/special/correl.php

 

The ordinal *event* of 'trendiness' is correlated with 'DE-trendiness' -- even if the cardinal trendiness is not. It's not as pretty, but it's still an inverse correlation.

I haven't had enough coffee, but I'm thinking (like you, qlai) that there must be a better term for it. I am abashed that I can't bring that better term to mind right now. Sheeesh.

 

Inverse correlation of Fractal Dimension Index.

 

I had to google that. Before I did, all I thought about was,"Mambo dogface to the banana patch."