"Reversion to mean" - most often used in stocks and financial discussions. Is it more universal? Does everything ultimately "revert to mean"?

I was listening to a financial podcast yesterday where they discussed that a particular stock would “revert to mean” – basically that while the stock was unusually high today, it would eventually lose value to a more ‘normal’ level.

Is “reversion to mean” (or sometime “regression to mean”) only relevant to financial markets?

Or is it generally applicable, for things like weather, behavior, economies, – anything that can be measured over time?

How applicable is it, in general?