The centralised exchange
A CEX is a company that holds your coins and keeps an internal ledger. Binance, Bybit, OKX and KuCoin all work this way. When you trade there, no blockchain is involved — rows change in the exchange database. That is why trades are instant and nearly free, and why the order book is deep.
The price of that convenience is trust. While your coins sit on the exchange, the exchange controls them. Hence verification requirements, the ability to pause withdrawals, and the risk of losing everything if the venue collapses.
The decentralised exchange
A DEX is a smart contract on a blockchain. Uniswap, PancakeSwap and Curve never hold your funds: you connect your own wallet and swap directly from it. No registration, no verification, open to anyone.
On most DEXs the price comes not from an order book but from an automated market maker formula: a pool holds two coins and the rate between them depends on their ratio. The larger your trade relative to the pool, the more it moves the price — that is slippage.
The substantive differences
- Custody. A CEX holds your coins; on a DEX they stay in your wallet.
- Speed. CEX trades settle instantly; a DEX swap waits for block confirmation.
- Cost. A CEX charges a percentage; a DEX charges a pool fee plus network gas, which is flat and makes small swaps uneconomic.
- Coverage. On a DEX a new token appears on launch day; on a CEX only after a listing that may never come.
- Risk. On a CEX you carry venue risk; on a DEX, smart-contract bugs and your own mistakes — a transfer to a wrong address is irreversible.
Why CEX–DEX gaps last longer
Between two centralised exchanges a gap closes fast, because bots sit with capital on both venues at once. Between a CEX and a DEX everything is slower. Closing such a gap means withdrawing coins to a wallet or depositing them back, paying gas and waiting for confirmations. That is why a few percent difference on freshly listed tokens can persist for hours.
The flip side is preparation: a wallet funded with the native coin for gas, knowledge of which networks the exchange supports for deposits and withdrawals, and readiness for gas to spike several-fold exactly when activity peaks.
What this service covers
SpreadRadar currently aggregates centralised venues: nine exchanges for futures and spot, and five P2P marketplaces. That is a deliberate choice — CEX data is uniform, sizes are verifiable and the routes are understandable for newcomers. The DEX material here is theory, so you can see the whole picture and understand why prices on decentralised venues may differ noticeably from exchange quotes.