Slippage

Slippage is the difference between the exchange rate you're quoted for a swap and the rate you actually receive once the transaction settles.

It happens because crypto prices move continuously, and a quote is only a snapshot in time. Between the moment you see a rate and the moment your deposit is confirmed on-chain and processed by an exchange partner, the market can move — sometimes in your favor, sometimes against it. The gap grows with market volatility and with the size of your order relative to available liquidity: a large swap in a thin market moves the price more than a small one in a deep market. This is different from a spread, which is the built-in gap between buy and sell rates rather than a timing effect.

Slippage matters most on floating-rate swaps, where the final rate is determined when your funds arrive rather than locked in advance. If you're swapping during a fast-moving market — a sudden rally or sell-off — the amount you receive can differ noticeably from the estimate shown at checkout. It matters less for small, routine swaps in calm markets, where the difference is often negligible.

On Zest, this trade-off is explicit at the point of choice: floating-rate orders track the live market rate through to execution, while fixed-rate orders lock in a rate for a limited window (shown as a countdown on the order screen), trading potential upside for certainty. If you want predictability — especially for larger swaps or during volatile stretches — a fixed-rate order removes slippage risk entirely, at the cost of a slightly less favorable starting rate. If you're comfortable with some variance and want the best available market rate, floating works fine for smaller, less time-sensitive swaps.

One practical way to reduce the impact of slippage over time, rather than trying to time any single swap perfectly, is dollar-cost averaging — spreading purchases across multiple smaller swaps instead of one large one. That way, no single moment of market movement determines your outcome. For a deeper walkthrough of how slippage behaves across different asset pairs and order sizes, see the crypto slippage guide.

Understanding slippage helps set realistic expectations before you swap: the quote you see is an estimate, not a guarantee, unless you've chosen a fixed-rate order that locks it in.