Bloomberg reported, citing unnamed sources, that a secret Bitcoin vault is located in a former military base in the Swiss mountains. The cryptocurrency's stockpiles are reportedly preserved in offline mode on the servers of the company Haro and it's currently worth some 10 billion dollars which, according to Bloomberg, is almost 98% of some 5,670 US banks' capital.
Haro provides a theft-proof system for storing its clients' Bitcoins, but it takes 2 days in order to withdraw your savings from this vault, which is a significant amount of time for markets. During this period the company checks the client's credentials, the legitimacy of the transfer request and then manually signs private transaction keys. However, it is currently one of the safest methods for storing cryptocurrencies.