A cryptocurrency exchange, or a digital currency exchange (DCE), is a business that allows customers to trade cryptocurrencies or digital currencies for other assets, such as conventional fiat money or other digital currencies. Exchanges may accept credit card payments, wire transfers or other forms of payment in exchange for digital currencies or cryptocurrencies. A cryptocurrency exchange can be a market maker that typically takes the bid–ask spreads as a transaction commission for is service or, as a matching platform, simply charges fees.
The exchanges can send cryptocurrency to a user’s personal cryptocurrency wallet. Some can convert digital currency balances into anonymous prepaid cards which can be used to withdraw funds from ATMs worldwide while other digital currencies are backed by real-world commodities such as gold.
The creators of digital currencies are often independent of the digital currency exchange that facilitate trading in the currency. In one type of system, digital currency providers (DCP) are businesses that keep and administer accounts for their customers, but generally do not issue digital currency to those customers directly. Customers buy or sell digital currency from digital currency exchanges, who transfer the digital currency into or out of the customer’s DCP account. Some exchanges are subsidiaries of DCP, but many are legally independent businesses. The denomination of funds kept in DCP accounts may be of a real or fictitious currency.
A digital currency exchange can be a brick-and-mortar business or a strictly online business. As a brick-and-mortar business, it exchanges traditional payment methods and digital currencies. As an online business, it exchanges electronically transferred money and digital currencies.
Often, the digital currency exchanges operate outside the Western countries to avoid regulation and prosecution. However, they do handle Western fiat currencies and maintain bank accounts in several countries to facilitate deposits in various national currencies.
Decentralized exchanges such as Etherdelta, IDEX and HADAX do not store users’ funds on the exchange, but instead facilitate peer-to-peer cryptocurrency trading. Decentralized exchanges are resistant to security problems that affect other exchanges, but as of mid 2018 suffer from low trading volumes.