Cryptocurrency is a digital asset created to be a means of exchanging value, built upon underlying immutable, distributed ledger technology known as blockchain. Cryptocurrency uses complex cryptography to keep transactions secure and transparent, as well as controlling the creation of additional units of the asset. All cryptocurrency, often called crypto tokens, digital currency, or virtual currency, is built on a modified version of the original Bitcoin blockchain. Since the creation of Bitcoin, over 4,000 different cryptocurrencies or altcoins have been created. The rise of cryptocurrency has created a new financial asset class and new unregulated financial market. Popular cryptocurrencies include Bitcoin, Ethereum, Litecoin, Ripple, Stellar, and many more.