TL;DR

Slippage is the difference between the price you expect for a trade and the price you actually receive when it executes. In DeFi, slippage comes from two sources: the price impact of your trade moving along the AMM curve, and price changes caused by other transactions executing before yours. Larger trades relative to liquidity experience more slippage.

How It Works

When you go to swap tokens on a DEX, the interface shows you an expected output (say, 1,000 TOKEN for your 1 ETH). But by the time your transaction actually executes on-chain, you might receive 985 TOKEN instead. That difference is slippage.

In an AMM context, slippage has two components. The first is price impact: the inherent cost of your trade moving along the pricing curve. In a constant product AMM (x * y = k), buying tokens reduces the token reserve and increases the base asset reserve, which pushes the price up with every unit purchased. The larger your trade relative to the pool, the further along the curve you travel, and the worse your average price.

The second component is timing. When you submit a transaction, it enters a mempool and waits to be included in a block. During that waiting period, other traders’ transactions might execute first, changing the pool state. MEV bots (maximal extractable value) can also front-run your trade: they see your pending transaction, execute a trade before yours to move the price, let your trade execute at a worse rate, then reverse their position for profit.

DEX interfaces let you set a slippage tolerance (e.g., 1%). If the actual execution price is worse than your expected price by more than this percentage, the transaction automatically reverts. Setting tolerance too low means frequent failed transactions in volatile markets; setting it too high means you accept larger losses and become a more attractive target for sandwich attacks.

A common misconception is that slippage is purely an AMM artifact. While price impact from the curve is often the dominant factor, the timing and MEV components can be significant, especially on chains with slow block times or high bot activity.

Try It Yourself

See exactly how much slippage different trade sizes cause: the Token Launch Simulator generates a slippage table showing price impact at $1K, $5K, $10K, and $50K trade sizes for your configured liquidity. Adjust the liquidity budget and watch the numbers change. Try the Token Launch Simulator →

Related Concepts

• Price Impact: The deterministic component of slippage caused by your trade size relative to pool reserves
• Liquidity: The amount of capital in the pool, which directly determines how much slippage occurs
• Constant Product AMM: The formula that creates the curved pricing relationship causing price impact
• Liquidity Pool: The reserve pool that your trade executes against
• Spot Price: The starting reference price before slippage is applied

Frequently Asked Questions

What is slippage in DeFi?

Slippage is the gap between the price shown when you submit a trade and the price you actually get when it executes on-chain. In AMM-based DEXs, it comes from your trade’s price impact on the pool curve, plus any price movement caused by other trades or MEV bots executing between when you submit and when your transaction is mined.

What is the difference between slippage and price impact?

Price impact is the theoretical price change your trade causes in the pool, calculated from the AMM formula and current reserves. Slippage includes price impact plus any additional price movement that happens during the time between submitting your transaction and it being included in a block. In a quiet market, slippage roughly equals price impact plus fees. In busy markets, slippage can be significantly worse.

How do you reduce slippage on a DEX trade?

The most effective way to reduce slippage is to trade on pools with deeper liquidity or to break large trades into smaller ones. You can also set a slippage tolerance in your DEX interface: if the actual price moves beyond this threshold, the transaction reverts instead of executing at a bad rate. Trading during periods of lower network activity can also reduce the timing component of slippage.

Why does slippage matter for token launches?

At launch, the liquidity pool is often shallow because it’s brand new. This means even moderate-sized trades can cause significant slippage, which discourages buyers and makes price discovery volatile. The Token Launch Simulator’s slippage table shows exactly how much slippage traders would experience at different trade sizes for a given liquidity.

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