Universal? Not likely. But this will serve: your edge is the knowledge you gain through your research and testing that a particular market behavior offers a level of predictability that provides a consistently profitable outcome over time.
An edge is outside of market behavior. A strategy works within market behavior.
An edge example from the past is 2 different FX dealers with one's prices lagging the other. That was a free money edge while it lasted.
Markets rhyme but they dont repeat-- this is a classic misunderstanding and is a tell tale sign of being tricked. Good luck! Surf