Exchange

A cryptocurrency exchange is an online platform that allows users to buy, sell, and trade cryptocurrencies. These exchanges serve as intermediaries between buyers and sellers, providing a platform for users to exchange one cryptocurrency for another or for fiat currency such as USD or EUR. At a high level, exchanges work by maintaining order books — lists of outstanding buy and sell orders — and matching buyers with sellers when prices align. When a trade executes, the exchange facilitates the settlement and takes a small fee for the service.

There are two main types of cryptocurrency exchanges: centralized exchanges (CEXs) and decentralized exchanges (DEXs). Centralized exchanges, such as Binance, Coinbase, and Kraken, are operated by companies that hold custody of user funds and manage the matching engine. They tend to offer high liquidity, fast execution, and user-friendly interfaces, but require users to trust the exchange with their assets. Decentralized exchanges, such as Uniswap and dYdX, allow peer-to-peer trading directly from users' wallets via smart contracts, giving users full custody but sometimes at the cost of liquidity or execution speed.

For algorithmic traders, the choice of exchange has significant implications for strategy design. Different exchanges offer different trading pairs, fee structures, API capabilities, and rate limits. HaasOnline integrates with many of the world's leading exchanges, allowing traders to connect their bots directly to exchange APIs and execute automated strategies without manual intervention. Evaluating an exchange's API reliability, order types supported, and historical data availability is an important step when setting up any automated trading system.