Outside of being worried about someone knocking you in the head to steal it or our friendly government or police deciding it was drug money and taking it, it would be a lot better holding good old 100 dollar bills cash rather than taking a negative interest rate to allow some bank to gamble with your money.

When you deposit money in a bank it is no longer your money. It is the banks money and you have a demand claim that they will give it back when you want it. But it is THEIRS to loan out and gamble with as they see fit (and the regulations will allow). When you hold 100 dollar bill Federal Reserve Notes, it is your money with no one else having a claim on it. Only problem is, if you hold much cash any more you are automatically deemed a criminal by law enforcement and government until you prove yourself innocent if you are holding very much of it.

Putting money in a financial institution at negative interest rates makes no sense whatsoever. Kind of like asking your deadbeat brother-in-law to keep a hundred dollar bill safe for you till you need it.

John