https://www.bloomberg.com/news/articles/2018-05-09/bunkers-for-the-wealthy-are-said-to-hoard-10-billion-of-bitcoin

Behind the guards, the blast doors and down corridors of reinforced concrete, sit the encrypted computer servers – connected to nothing – that hold keys to a vast digital fortune.

Argentine entrepreneur Wences Casares has spent the past several years persuading Silicon Valley millionaires and billionaires that Bitcoin is the global currency of the future, that they need to buy some, and that he’s the man to safeguard it. His startup, Xapo, has built a network of underground vaults on five continents, including one in a decommissioned Swiss military bunker.

Wences Casares

Photographer: Daniel Acker/Bloomberg

In the rarefied world of wealth management, Xapo is known for a client list studded with family offices, and for occasionally letting a journalist peek into a stronghold to write about its security. But one secret has proven elusive: how much digital cash does it really hold?

Two Xapo clients said it houses roughly $10 billion of Bitcoin. Another person close to the venture called the figure an accurate approximation. Bitcoin’s price, after all, is hardly steady.