How to compare two non stationary time series

Question

I have searched a long time for comparison between non stationary time series but I'm a bit lost.

I have two time series (black and red below) and I want to prove statistically they are very similar.

This is the plot of my time series:

Could someone help me on the steps I need to perform please?

Answer 1

If you want to compare two series you can count correlation coefficients from them, I think this is what you need.