What Is CEX-DEX Arbitrage? Gas, Price Impact and Bridges

CEX-DEX arbitrage is trading the price or funding difference for the same asset between a centralized exchange (CEX) and a decentralized exchange (DEX). The logic is the same as any crypto arbitrage: buy low, sell high, or hold opposite positions to collect a funding gap. What changes is the cost structure, because a DEX adds gas fees, pool price impact, and often a bridge between chains.

Key takeaways

• There are two main types: spot DEX (AMM pools) vs CEX, and perp DEX vs CEX.
• AMM prices move only when someone trades, so they often lag CEX prices.
• On a DEX, price impact is set by pool size and grows quickly with trade size.
• Gas fees are paid per transaction, even when the transaction fails.
• Moving funds often requires a bridge, which adds time, fees and smart contract risk.
• Perp DEXs usually pay funding hourly, so normalize rates before comparing with CEXs.

Two kinds of CEX-DEX arbitrage

A CEX vs DEX comparison is the starting point. A centralized exchange matches orders in an order book and holds your funds. A decentralized exchange runs on a blockchain, and you trade from your own wallet.

	Spot DEX vs CEX	Perp DEX vs CEX
DEX side	Token swap in an AMM pool	Perpetual futures on an on-chain venue
Typical edge	Price gap between pool and order book	Funding rate spread, sometimes price gap
Main DEX costs	Pool fee, price impact, gas	Trading fee, funding, deposit bridge
Holding time	Seconds to minutes	Hours to weeks
Typical venues	Uniswap, Jupiter, other AMMs	Hyperliquid, dYdX and similar

Spot DEX vs CEX: how price impact works

Most spot DEXs use an automated market maker (AMM). A basic constant-product pool keeps x × y = k, where x and y are the pool's two token balances. The price is simply the ratio of the balances, and it only changes when someone trades. When a CEX price moves, the pool keeps the old price until an arbitrageur trades it back into line. That lag is the opportunity.

Your own trade moves the pool price, which is slippage caused by price impact. The larger the trade relative to the pool, the worse your average price.

Worked example: buy on a DEX, sell on a CEX

Assume these illustrative numbers:

• AMM pool: 1,000 ETH and 3,000,000 USDC, so the pool price is $3,000 and k = 3,000,000,000.
• Pool fee: 0.3% of the input.
• CEX best bid: $3,030, with enough depth for your size.
• CEX taker fee: 0.05%. Gas: $5 per swap.
• You hold USDC in a wallet and ETH on the CEX already (pre-positioned inventory).

Buying 5 ETH from the pool:

• ETH left in the pool: 995
• USDC the pool must hold: 3,000,000,000 ÷ 995 = 3,015,075.38
• USDC added to the pool: 15,075.38, and with the 0.3% fee you send 15,075.38 ÷ 0.997 = $15,120.74
• Average price: 15,120.74 ÷ 5 = $3,024.15

Item	Amount
Sell 5 ETH on the CEX at $3,030	+$15,150.00
CEX fee (0.05%)	−$7.58
Buy 5 ETH on the DEX	−$15,120.74
Gas	−$5.00
Net profit	+$16.68

After your trade, the pool price is 3,015,075.38 ÷ 995 ≈ $3,030, the same as the CEX bid. Your trade closed the gap.

Now try 10 ETH. The pool would need 3,000,000,000 ÷ 990 = 3,030,303.03 USDC, so you add 30,303.03 plus the fee, or $30,394.21 in total. That is an average of $3,039.42, above the $3,030 CEX bid, so the larger trade loses money. On a DEX, the right size is often smaller than it looks, and the arbitrage profit calculator helps find it.

Perp DEX vs CEX

Perp DEXs such as Hyperliquid and dYdX offer perpetual futures with on-chain or hybrid settlement. The usual trade is a funding rate arbitrage: short where funding is higher and go long where it is lower.

Two details matter:

• Funding intervals differ. Many CEXs pay every 8 hours, while Hyperliquid pays hourly. Convert to APR first: APR = rate ÷ interval hours × 8,760.
• Collateral must reach the DEX. Perp DEXs often take USDC on a specific chain, so you may need to withdraw from a CEX to that chain or bridge from another one.

Many perp DEXs charge a trading fee instead of gas on every order, but the venue still carries smart contract and oracle risk.

Gas, bridges and MEV

Gas is the fee paid to the blockchain for each transaction. It depends on network demand, not on trade size, so it hurts small trades most, and you still pay it if a swap fails because the price moved past your slippage tolerance.

Bridges move tokens between chains. They add fees and waiting time, and bridge contracts have been a frequent target of exploits. Many traders avoid bridging during a trade and pre-position funds on each chain instead.

MEV (maximal extractable value) is profit that block builders and bots take by reordering transactions. A visible arbitrage swap can be front-run or sandwiched. Private transaction relays and tight slippage settings reduce, but do not remove, this risk.

Risks and common mistakes

• Same ticker, different token. A token on a DEX may share a ticker with an unrelated CEX listing. Always match the contract address.
• Wrong network. Sending a token over a network the receiving exchange does not support for it can delay or lose funds.
• Ignoring pool depth. A gap in a small pool may support only a tiny trade.
• Counting gas once. A round trip may need approvals, swaps and a transfer, each with its own gas.

See arbitrage risks for the full list.

How ArbTide helps

ArbTide compares prices and funding rates across CEXs and perp DEXs on its live arbitrage scanner and funding rate pages. The CEX-DEX arbitrage strategy page explains how to evaluate these routes.