I often need to argue with people that pretends that the equities bull market is at the edge of a crash. And now for years...
Just have a look at Google "most hated bull market", headlines are countless and even since 2011! Lot of noise, lot of bodies in the graveyard.
So I often tell them to just stick to what you can see technically, and to be honest, the bull market has been steady growing. So basically this chart can give an answer to people that spend a lot energy at arguing whether we will see a bear market or no.
I don't pretend the ratio is a great indicator for a bear market, but at least I think it can gives a signal and some food for thoughts.