Slippage
The difference between the price you're quoted when you place an order and the price at which it actually fills. It grows with the size of the order and with how fast the market moves.
Slippage comes from two things. The market can move between the moment you’re quoted a price and the moment your order fills: FINRA, the US brokerage industry’s regulator, warns that with an order at the market price “you might not get the price you saw or were originally quoted, especially in fast-moving markets.” And a large order, or one in a thin market, moves the price against itself as it fills. On a decentralized exchange, Uniswap explains, larger swaps move the pool’s price further.
Two tools limit it:
- A limit order buys or sells only at the price you set or better. The risk, FINRA notes, is that it doesn’t execute at all.
- A slippage tolerance, on a decentralized exchange: in Uniswap’s words, “the maximum percentage you’ll allow the quoted price to move.” If the price moves further, the swap fails, and you still pay the network fee.
When it goes wrong
In March 2026, a user swapped about 50 million dollars in stablecoins for another crypto token through a decentralized app, and received tokens worth about 36,000 dollars, according to The Block. The app had warned of “extraordinary slippage” and required a checkbox; the user ticked it on a phone and went ahead. The app’s founder said it would try to return the 600,000 dollars in fees it had collected from the trade.
Slippage is a risk mainly for large orders, thin markets and swaps on decentralized exchanges, and a warning about it is worth reading twice. The guide on what buying bitcoin really costs covers the other costs of a trade. See also spread and payment for order flow.