What Is a Slippage Tolerance Setting?

A slippage tolerance setting is the maximum price worsening you're willing to accept between the price you expected and the price you actually get. Set it at 0.5% on a trade you expect to cost $100, and you're saying: fill me at up to $100.50, but no worse — past that, cancel rather than execute.

What does a slippage tolerance actually control?

It draws a hard line between "slightly worse than expected" — acceptable — and "too much worse" — rejected. Slippage itself is the gap between the price you saw when you sent an order and the price you were actually filled at; it appears because the market moves and other people's orders consume the available prices while yours is in flight. The tolerance setting caps that gap. Worked example: you're buying a coin quoted at $100 with tolerance set to 0.5%. Your worst acceptable price is $100 × 1.005 = $100.50. A fill at $100.30 goes through — inside the line. If filling would require paying $100.80, the trade is rejected or fails instead of executing. When you're selling, the same logic points the other way: $100 expected with 0.5% tolerance means you'll accept no less than $99.50.

What happens when the price moves past my tolerance?

Your trade doesn't execute — which is the setting doing its job, even when it feels like a failure. On decentralized exchanges, where the setting is most prominent, the transaction simply reverts: no trade, though you may still pay a network fee for the attempt. In bot platforms, the equivalent protection rejects the order and the strategy has to decide what's next — retry, wait, or skip the trade. Either way you're left un-executed, and that's the point: the alternative was being executed at a price you'd already defined as unacceptable. A rejected trade costs you a missed opportunity; a bad fill costs you actual money on every occurrence. The tolerance setting is you choosing, in advance, which of those costs you'd rather pay.

Should I set slippage tolerance tight or loose?

Tight protects your price and misses more trades; loose fills more trades and protects you less — pick based on which failure hurts your strategy more.