Bitcoin - Digital Currency, trading at US$7/BTC
Bitcoin is a digital currency created in 2009 by Satoshi Nakamoto. The name also refers to the open source software he designed that uses it, and the peer-to-peer network that it forms. Unlike most currencies, bitcoin does not rely on trusting any central issuer. Bitcoin uses a distributed database spread across nodes of a peer-to-peer network to journal transactions, and uses cryptography to provide basic security functions, such as ensuring that bitcoins can only be spent by the person who owns them, and never more than once.