First, let me make a distinction between a Bitcoin and a bitcoin. Yes, there is a difference, besides the obvious upper and lower case letter B. Bitcoin (with uppercase B) is a software that enables the creation and transfer of digital money called bitcoin (with lowercase b). And bitcoin is the first decentralized cryptocurrency, a form of electronic cash. It is a digital currency designed to work without the need for a third party such as a Central bank or other intermediaries. Stock symbol for bitcoin is BTC, and its subunits are called millibitcoin (1⁄1000) and satoshi (1⁄100000000). Satoshi is a pseudonym of the creator of both Bitcoin and bitcoin, but his true identity is still unknown.