A cryptocurrency exchange is a business that enables customers to trade digital currencies for other assets, such as fiat money or other cryptocurrencies, typically earning revenue through bid-ask spreads or transaction fees. These platforms vary in operation: some are centralized and allow withdrawals to personal wallets, while decentralized exchanges (like Etherdelta and IDEX) facilitate peer-to-peer trading without storing user funds, though they suffer from low trading volumes. The industry has a notable history of regulatory crackdowns, beginning in 2004 when three Australian exchanges shut down after the ASIC deemed they required a financial services license. In 2006, the U.S. Secret Service shut down Gold Age Inc., whose operators, Arthur Budovsky and Vladimir Kats, were indicted for transmitting over $30 million without a license and later sentenced to probation in 2007. That same year, the U.S. government ordered the digital currency system E-Gold to lock approximately 58 accounts linked to various gold-backed exchanges. To sidestep such regulations, many exchanges operate outside Western countries while still maintaining bank accounts there to handle fiat currencies.