You click "buy" at $42,000, the order fills, and you check the receipt — you actually paid $42,180. That $180 gap is called slippage, and it's one of the most overlooked costs in crypto trading.
Why Slippage Happens
When you place a market order, the exchange matches you against the order book — a list of pending buy and sell orders at different prices. If you're buying, the exchange starts filling your order from the cheapest available sell order, then the next cheapest, then the next. If your order is larger than what's available at the best price, it "eats through" multiple price levels, and your average fill price ends up higher than the price you saw on screen.
Three Things That Make Slippage Worse
- Large orders: Buying $50,000 of a low-cap token? Your order will blow through thin order book levels, and the price you actually pay could be significantly worse than the displayed price.
- Low liquidity: Coins with low trading volume have thin order books — fewer pending orders at each price level. Small orders can still cause big price moves.
- High volatility: During rapid price movements, the order book changes between when you submit and when the exchange processes your order. The price you saw may be gone by the time your order executes.
How to Reduce Slippage
The simplest fix: use limit orders instead of market orders. A limit order lets you set the maximum price you're willing to pay. If the market can't fill your order at that price, it simply waits — you never pay more than you intended. The trade-off is that your order might not fill immediately, or at all. Learn more about order types in our guide to market orders vs limit orders.
For DEX swaps (like Uniswap or PancakeSwap), most interfaces let you set a slippage tolerance — a percentage below which you're okay with slippage. Setting it to 0.5% means if the price moves more than 0.5% before execution, the transaction fails rather than filling at a bad price. The default is usually 0.5-1%, but you may need to increase it for volatile or illiquid tokens.
Slippage on DEXs vs Centralized Exchanges
On centralized exchanges (like Coinbase or Kraken), slippage comes from the order book. On decentralized exchanges (DEXs), it comes from the liquidity pool — a different mechanism but the same result. DEX swaps also include an additional consideration: large trades relative to pool size move the price more, because the pool's pricing formula is curve-based. This is why splitting large swaps into smaller transactions can reduce overall slippage.
The Bottom Line
Slippage isn't a scam or a bug — it's a natural consequence of how markets work. But it's a real cost that adds up over hundreds of trades. If you're placing market orders on small-cap coins without checking the order book, slippage could be quietly eating your returns. The fix is simple: use limit orders when precision matters, check liquidity before large trades, and always set a slippage tolerance on DEX swaps.
For a deeper understanding of how fees and transaction costs work, check our gas fees guide and our guide to crypto exchanges.
CGH Take: Slippage is the tax on impatience. If you're willing to set a price and wait, you don't pay it. If you need it now, you do.