Price Impact
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Key Takeaway
Price impact is the percentage change in a token's exchange rate caused by a specific trade, resulting from the shift in pool token ratios produced by the transaction.
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What Is Price Impact?
Price impact is the percentage change in a token's exchange rate caused by a specific trade, resulting from the shift in pool token ratios produced by the transaction.
How Price Impact Works
Frequently Asked Questions
What is price impact on a DEX swap?
Price impact on a DEX swap is the percentage by which your trade moves the token's exchange rate against you during execution. On AMM-based decentralized exchanges, token prices are set by the ratio of assets in the liquidity pool. When your trade shifts that ratio, it worsens your effective exchange rate for the portion of the trade executed at each successive price level. Price impact is displayed as a percentage on most DEX interfaces before you confirm, allowing you to assess whether the trade is cost-effective before committing to the transaction.
What is considered a high price impact on a DEX?
Price impact above 1% is generally considered notable on a DEX swap, signalling that your trade is meaningfully large relative to the pool's available liquidity. Impact above 2%–3% represents a significant execution cost that many experienced users would seek to reduce by splitting the trade or using an aggregator. Some DEX interfaces display a warning when price impact exceeds a threshold — typically 1% to 5% depending on the platform. Impact above 5% is generally considered high and warrants serious consideration of alternative execution strategies before confirming the swap. Always treat price impact as a direct cost, not just an informational warning.
How is price impact different from slippage on a DEX?
Price impact and slippage are related but measure different things. Price impact is the predictable, deterministic price movement caused specifically by your own trade shifting the pool's token ratio during execution — it is calculated before you submit the transaction. Slippage is the total difference between the price quoted when you submitted the transaction and the price at which it actually executed, which includes your price impact plus any additional price movement from other trades that were processed in the same blockchain block. Price impact is one component of slippage; external block-level price movement is the other.
Common Misconceptions About Price Impact
Price impact is the same as the swap fee charged by the protocol.
Price impact and swap fees are separate costs that both reduce the value received from a DEX trade but operate through entirely different mechanisms. The swap fee is a fixed percentage charged by the protocol on each transaction and distributed to liquidity providers. Price impact is an additional cost that arises from your trade shifting the pool's token ratio, and it scales with trade size relative to pool liquidity. Both costs should be added together when calculating the true total cost of executing a swap on a decentralized exchange.
Setting a high slippage tolerance on a DEX reduces price impact.
Slippage tolerance and price impact are different concepts. Slippage tolerance is the maximum percentage difference between the quoted price and execution price that you are willing to accept before the transaction automatically reverts. Increasing it does not reduce the price impact your trade causes — it simply widens the boundary within which the transaction is allowed to complete. A high slippage tolerance means you accept more total price deviation, which increases the risk of a worse outcome, particularly in fast-moving markets where front-running bots can exploit high slippage tolerances to extract additional value from your transaction.
Price impact only applies to DEX trades, not to centralized exchange orders.
Price impact occurs on both centralized and decentralized exchanges, though the mechanism differs. On centralized exchanges, market impact arises from large orders sweeping through stacked limit orders at progressively worse prices in the order book. On AMM-based DEXs, price impact arises from the pool ratio shift caused by the trade. The term price impact is most commonly used in the DEX context because it is explicitly calculated and displayed before execution, whereas on centralized exchanges the equivalent concept is usually referred to as market impact or simply slippage within the order book.