Centralized Exchange

Key points

• A centralized exchange, or CEX, is a platform operated by a company that custodies users' funds and intermediates trades.
• It offers high liquidity, fast execution, and a simple experience, but concentrates custody of the assets on the platform itself.
• It's where most users make their entry into crypto, converting fiat currency into digital assets, and their exit back to a bank account.

What is a centralized exchange?

A centralized exchange is a crypto market operated by a company that acts as an intermediary between buyers and sellers. The user deposits funds on the platform, trades within its system, and withdraws whenever they want. It's the model closest to a traditional brokerage, with registration, an account, and an interface that hides the technical complexity of on-chain operations.

How it works

The CEX maintains an order book with buy and sell orders and matches those orders in its own system, often off the blockchain to gain speed. Users' balances sit in wallets controlled by the company, and the record of who owns what is internal. Only deposits and withdrawals actually cross the blockchain.

Because it operates in a centralized way and connects the banking system to the crypto world, the platform must comply with customer identification and anti-money laundering requirements. Registration, identity verification, and tier-based limits are part of the flow, and access usually depends on that registration being approved.

This structure delivers concentrated liquidity and agile execution, at the cost of the user trusting the company with custody of the assets while they sit on the platform.

Why it matters

The centralized exchange is the most common entry point into the ecosystem. A user who wants to convert reais into a stablecoin typically starts with a CEX or a crypto on-ramp service, and uses the same infrastructure to convert back to local currency. The liquidity these platforms concentrate is what makes conversion predictable.

Risks and limitations

The main risk is counterparty risk: while funds sit on the platform, the user depends on the company's solvency and integrity, and management or security failures have already caused significant losses in the past. Add to that exposure to platform decisions, such as withdrawal suspensions. The maxim that whoever doesn't control the keys doesn't fully control the funds sums up this limitation. That's why many users keep on the platform only what they need to operate and transfer the rest to a wallet under their own control.