Bitcoin is valuable because it is useful as a form of currency. Bitcoin has the mathematical characteristics of money (persistence, portability, interchangeability, scarcity, separability and identifiability), rather than relying on physical characteristics (such as gold and silver) or the trust of central authorities (such as legal tender). In short, Bitcoin is supported by mathematics. With these characteristics, the value that a currency form needs is trust and use. For Bitcoin, this can be reflected in its growing base of users, merchants and start-ups. Like all currencies, the value of Bitcoin comes directly from people who are willing to accept it as a payment method, which is the only source.