5. Matthew Mellon
NetWorth: $900 million to $1 billion
Heir to one of the greatest fortunes in the American banking world, Matthew Mellon began investing in the world of cryptocurrencies several years ago despite the reluctance of those around him. As an early investor in the Blockchain Ripple token, XRP, he was able to build up quite a small fortune. As a reminder, the Blockchain Ripple sees itself as the replacement for the SWIFT interbank system in the future.