Slippage

Slippage is the difference between the price you expect when you submit a swap and the price you actually receive when the trade executes. On a decentralized exchange, the quote you see reflects the pool's state at that instant, but other transactions can land before yours and move the price in either direction. The result is that your executed price can be worse than quoted (negative slippage) or occasionally better (positive slippage).

Slippage is often confused with price impact, but they are distinct. Price impact is the price movement caused by your own trade and is predictable from pool depth, while slippage covers the additional, unpredictable deviation caused by everyone else's activity between quote and execution. Most interfaces let you set a slippage tolerance, the maximum deviation you will accept before the transaction reverts. Set it too tight and legitimate trades fail in volatile markets. Set it too loose and you invite sandwich attacks, where bots front-run and back-run your trade to capture the gap you allowed.

You can reduce slippage by trading in deep, liquid pools, splitting large orders, and using routers that aggregate liquidity across venues. Aggregated routing, such as Tessera's single-trade routing across DEXs and ERC-4626 vaults, spreads a trade across venues instead of pushing it all through one pool, which can help on multi-asset baskets. Slippage never disappears entirely, so treat it as a real trading cost, especially for volatile or thinly traded assets.