Where do millionaires keep their money safe?

How do millionaires ensure the safety of their vast wealth? Do they rely solely on traditional banking systems or have they embraced alternative methods such as cryptocurrency and blockchain technology for secure storage? What measures do they take to protect their assets from potential threats, both physical and digital? Are there specific security protocols that they adhere to, or do they customize their approach based on their unique circumstances? How do they weigh the risks and benefits of different storage options, and how do they stay informed about the latest advancements in the field?