Bitcoins can be bought on bitcoin exchanges such as Okcoin, Coinbase, Kraken and expresscoin that trade them for real money using instruments such as credit and debit cards as well as wire transfers. The bitcoins can be stored in a secured wallet that can be located either on the hard drive of your computer or on your mobile phone. Special hardware devices called physical bitcoin wallets are also available. Users can also store bitcoins online with providers offering the service, but they must be wary of security breaches and the fact that the holdings are unlikely to be insured. Additionally, one can receive bitcoins as payment for services provided. Bitcoins can also be bought from individuals who own them.