Do you guys use any "risk" metric?

I always struggled to find the balance between completely ignoring markets and knowing its every move. I thought maybe having a "risk metric", even if it's a bit dumb, will allow me to somewhat ballpark know when it's time to pay attention and things are getting really heated/undervalued.

However I've been struggling to find a good one (especially one that would send me notifications and not require me to come back to the dashboard every day/week to check it). Do you guys use one, and if so, which ones?