Exchange

An exchange is a marketplace where people buy, sell, and trade cryptocurrencies — the crypto equivalent of a stock brokerage combined with a trading venue. Exchanges match buyers with sellers, publish live prices, and typically let users convert between fiat money (like dollars or euros) and crypto, as well as between different crypto assets.

There are two main types. Centralized exchanges (CEXs), such as Coinbase, Binance, or Kraken, are companies that hold customer funds, run order books, and require identity verification (KYC). Decentralized exchanges (DEXs), such as Uniswap, are smart-contract protocols where users trade directly from their own wallets without an intermediary holding their assets. For example, a newcomer might link a bank account to a centralized exchange, buy 100 euros of bitcoin, and either leave it in the exchange account or withdraw it to a personal wallet.

A common misconception is that assets left on an exchange are as safe as money in a bank; exchange balances are claims on a company, not coins you control, and exchange failures such as FTX's collapse in 2022 showed customers can lose funds when a platform fails — hence the saying "not your keys, not your coins." Centralized exchanges remain the main on-ramp into crypto because of their convenience and fiat support, but many users withdraw significant holdings to self-custody wallets they control.