It's been some correlation between "neutrality" and "money" for centuries. They go hand in hand.
Sometimes it's really hard to tell the effect from the cause.
Also, it's easy to imagine "Neutrality brings us moneys! Let's stick with it.". Not saying if it's 100% true, of course.
You state still this falsehoods after I pointed out that
* other swiss pecularities (e.g. their banking laws about anonymous number accounts) might be more to blame
* other european neutral countries didn't exhibit any correlation between neutrality and money?
If you talk about correlation, then you need to take in the full data set. You speak general about neutrality, so take in ALL neutral countries. Malta, Ireland, Austria, Liechtenstein. And maybe even neutral microstates like Vatican.
Only THEN can you come to a conclusion. But not by only focusing on one single country, and extrapolating your observation to all of neutrality.