A crypto exchange is a platform where you can buy and sell digital assets. The word is used broadly enough to cover very different kinds of operations: huge centralised spot exchanges like Binance, Coinbase, Kraken and OKX; regulated US-focused venues like Gemini and Bitstamp; derivatives-focused platforms like Bybit and Deribit; and, by extension, decentralised exchanges like Uniswap and Jupiter even though they work completely differently under the hood. When someone says “an exchange” without qualification, they almost always mean a centralised one.
Centralised exchanges do roughly what a stock brokerage does. You open an account, deposit fiat or crypto, and trade against an order book that the exchange operates. The exchange holds custody of your assets while you use the platform, matches your orders against other users’ orders (or against its own market makers), and charges a fee per trade. Withdrawals of crypto go to an address you specify; withdrawals of fiat go through a bank.
The Centralised Exchange Landscape
Binance is by a wide margin the largest exchange in the world by volume and has been for years. Coinbase is the largest US-regulated platform and is publicly traded on NASDAQ. Kraken, OKX, Bybit, Upbit (in Korea), Bitget, KuCoin, HTX (formerly Huobi), and Bitstamp fill out the rest of the top tier. Between them they handle the overwhelming majority of spot and derivatives trading globally.
Regulation varies enormously between jurisdictions. Coinbase, Kraken, Gemini and Bitstamp operate under US state and federal licences and are treated by US regulators as similar to money transmitters or securities brokerages. Binance has had a complicated relationship with US law and now runs Binance.US as a separate entity for American users. Several jurisdictions — Japan, Singapore, the EU under MiCA — have explicit licensing regimes for crypto exchanges. Others do not, and the exchange operates in a grey zone that has historically been fine right up until it was not.
The Obvious Risk
Exchanges are custodial. When you have a balance on an exchange, what you actually have is a claim on the exchange — they hold the underlying crypto on their books (they might be custodying it themselves, or using a third-party custodian like BitGo, or running a hot wallet they control). If the exchange fails — bankruptcy, hack, internal fraud, regulator seizure — your ability to recover the crypto depends on the insolvency process, which historically has been slow, partial, or catastrophic.
Mt. Gox (2014), QuadrigaCX (2019), FTX (2022) and Celsius (2022) are the headline examples. Each of them had billions of dollars of customer assets on the books that turned out to be mismanaged, stolen, or nonexistent. Each of them felt completely safe right up to the moment they did not. The lesson everyone eventually learns is that exchange balances should be treated as operational liquidity, not as storage — move the bulk of your holdings to self-custody and leave only what you need to trade on the platform.
This advice is repeated constantly and is still ignored constantly. Each new cycle brings a new wave of users who leave serious balances on exchanges because it is convenient and then get taught the lesson the hard way.