it's intellectual property too right?

Magicians don't patent magic tricks because in doing so, they would have to reveal how the trick is done.
The method magicians use to protect the tricks of their trade is just to keep secrets secret.
but once you performed it, other magicians will figure out how it's done and you've lost the edge.
Not necessarily. Once you perform an original trick, it becomes "yours". It's considered very bad form to steal someone else's trick and if you get caught doing it, your reputation basically goes to shit.
The same reason why Cocal Cola Coke never patended their softdrink