On an <a href="/glossary/order-book/">order book</a>, the quoted price applies only to the orders sitting at that level. If you want more than is offered there, the rest of your trade fills at the next-best level, and the next, working up or down the book. Your final price is a blend of everything you consumed. A small order barely notices; a large one in a quiet market can walk through several levels and settle far from the headline number.
Automated market makers behave similarly for a different reason. A <a href="/glossary/liquidity-pool/">liquidity pool</a> prices assets from the ratio of its reserves, so your trade itself shifts that ratio and therefore the price, continuously, as it executes. The bigger your trade relative to the pool, the further along the curve you push, and the worse your average price. Deep pools absorb size gently; shallow ones punish it hard.
This is why liquidity matters so much for real costs. A token can quote an attractive price while having almost nothing behind it, and thin books hurt twice: you pay more going in, and you may find no buyers at a sensible price when you want out. Slippage also grows with volatility, because the price can genuinely move between you signing a transaction and it being included in a block.
Most interfaces let you set a slippage tolerance, which is the worst price you will accept before the trade reverts. Setting it too tight means failed transactions in fast markets; setting it very wide is an open invitation, because bots watching pending trades can trade in front of you and hand back the worst price your tolerance permits. Splitting large orders and using limit orders where available are the usual defences.
How to Read a Crypto Price Chart
Key takeaways
- Slippage is a liquidity cost, not a fee line, and it does not appear on the quote you first see.
- A wide slippage tolerance protects against failed transactions but exposes you to being sandwiched by bots.
- Check depth before size: a thin market can make a modest trade far more expensive than the headline price suggests.
Slippage — frequently asked questions
Is slippage always bad for me?
Not always. Prices can move in your favour between placing and filling, which is positive slippage, and some venues pass that back to you. It is asymmetric in practice, though: the same thin liquidity and fast moves that occasionally hand you a better fill are far more likely to hand you a worse one, especially on illiquid pairs and during sharp market swings.
How do I reduce slippage?
Trade where the liquidity actually is, break a large order into smaller pieces, and use limit orders rather than market orders when the venue supports them. Avoid trading into an obviously thin pool or book, and be cautious during volatile stretches. On-chain, a slightly higher fee that gets you included faster can also reduce how much the price drifts before execution.
New to crypto, or filling in the gaps? Work through the essentials in Learn, browse every term A–Z, or see live prices for the coins these concepts power.