For centuries, gold has held a unique role: as a form of currency, a store of value and sometimes a speculative or alternative asset to stocks and bonds. No other asset has managed to retain such an allure over time.

And over the centuries, there have been other pretenders for gold's throne (salt, florins or ducats, anyone?) but none has survived. The latest potential competitor for gold may be bitcoin, the cryptocurrency created in 2009 as open-source software for a decentralized form of payment.