Slippage Explained: Why Your Crypto Trade Almost Never Fills at the Exact Price You Saw
You tap "swap" on your favorite DEX. The screen says you'll get 1,000 USDC for your ETH. You confirm. Ten seconds later, the transaction lands — and you actually got 994 USDC. Nobody stole from you. No hack. No bug.
You just met slippage, one of the most misunderstood concepts in crypto trading. Whether you're swapping on Uniswap, filling an order on a centralized exchange, or aping into a fresh memecoin, slippage is quietly shaping every price you touch. Understanding it is the difference between a trader who feels ripped off and one who knows exactly what happened.
What Slippage Actually Is
Slippage is the difference between the price you expected to get and the price you actually got.
If you expected to buy ETH at $3,000 and you paid $3,015, that's $15 of slippage — half a percent. If you expected to sell 1 SOL for $150 and you received $148.50, that's $1.50 of slippage — one percent.
Slippage can be positive too. Sometimes you get a slightly better price than expected. But in practice, especially when you're the one initiating a trade, slippage almost always works against you. There's a structural reason for that, and we'll get to it.
The key insight: slippage is not a fee. Nobody charges it. It's not a hidden tax collected by the exchange. It's simply a consequence of how markets — and especially blockchain markets — actually work.
Why Slippage Exists
Imagine a farmer's market with one apple seller. She has ten apples at $1 each. You buy two — easy, $2 total. Now imagine you want fifteen apples. You buy all ten at $1, then have to find another seller who might charge $1.50 for the extra five. That $0.50 premium is your slippage.
Every market works this way. There's...