Physical Bitcoins

Physical bitcoins are tangible objects, usually metal coins or bars, that carry a private key for a bitcoin address hidden beneath a tamper-evident hologram or seal. The matching address is visible, so anyone can check the balance on the blockchain, but only someone who peels off the seal can spend the coins, and doing so leaves visible damage. The best-known examples are Casascius coins, made in the United States from 2011 by Mike Caldwell, who stopped selling funded coins in 2013 after FinCEN indicated the business could count as money transmission. Other makers have produced similar items since. Unopened early coins are now valued as collectibles, sometimes above the bitcoin they hold. Buyers must trust that the maker did not keep a copy of the key, and counterfeits exist. Many decorative "bitcoin" coins contain no bitcoin at all. Also see paper wallet and cold storage.