I would assume that banks have some cold backups in a mountain somewhere, like this for example: https://www.mount10.ch/en/mount10/swiss-fort-knox/ https://www.

I would assume that banks have some cold backups in a mountain somewhere, like this for example: https://www.mount10.ch/en/mount10/swiss-fort-knox/ https://www.mount10.ch/en/mount10/swiss-fort-knox/ Although I'm not sure if it could withstand a nuke, its in a mountain, so, maybe?