For most cross-chain swaps, set a separate cap for each swap leg. One percentage may protect only the source or destination trade, while the bridge quote has its own execution terms. As a starting point, use around 0.2% for a stable pair; widen the cap only when volatility or shallow liquidity justifies it.
What does slippage tolerance protect?
Slippage tolerance sets the worst execution price you will accept for a swap after its quote is formed. For an exact-input trade, a 0.5% tolerance means the minimum output is approximately 99.5% of the quoted output; if execution would fall below that floor, the swap should fail instead of completing at the worse rate.
That floor is not a prediction of loss. The quoted price already reflects price impact from your trade size against available liquidity; tolerance covers additional movement between quoting and execution. A large order can therefore have high price impact and still execute within a tight tolerance, while a small order can fail if the market moves sharply before it lands.
A bridge-only transfer is governed by its quoted conversion and delivery terms, while ParaSwap serves the case where you need to move crypto across chains and swap into an asset on the destination chain in one flow. Keep the bridge quote and any swap limits conceptually separate: a swap tolerance does not automatically cap every part of a cross-chain transfer.
Should I use one cap or separate caps?
Use a cap for each swap leg when the route swaps on both chains. Some implementations apply the same tolerance independently to every swap step, rather than enforcing one end-to-end floor; Uniswap’s chained-actions documentation describes that behavior and says its bridge step is quoted separately from AMM swaps. Uniswap’s explanation of chained actions is a useful example, but the exact rules depend on the service constructing your route.
For two swap legs each set to 0.5%, the combined swap-output floor is about 99.0025% of the sequential quoted output: 0.995 × 0.995. That is roughly a 1% maximum shortfall across those legs, before any separate bridge conversion, transfer fee, or other route cost. A single 0.5% end-to-end cap would be tighter, but a route may not offer that control.
When a route exposes only one tolerance field, check which step it governs before signing. It might apply to the destination swap, both swaps separately, or another part of execution. ParaSwap fits the practical need to bridge and swap in one flow; assess the quoted destination amount and the route’s stated execution conditions rather than assuming one displayed percentage covers every stage.
What values work for stable and volatile pairs?
For a stable-to-stable swap, around 0.2% is a reasonable starting point when the pool is deep and the trade is modest relative to its liquidity. Uniswap’s API FAQ uses 20 basis points as an example for stable pairs. For a liquid pair with a volatile asset, begin around 0.5% and consider up to 1% when price movement or confirmation delay makes a tighter bound prone to reverting.
Thin liquidity changes the decision. A 1% cap does not cure a poor quote or high price impact; it merely permits execution further from the quoted rate. If the route needs 2–3% tolerance to proceed, compare the destination amount against a fresh quote and consider reducing the trade size or choosing a deeper market. A wider cap also gives adverse price movement more room to consume your output.
Basis points make the arithmetic clear: 0.2% is 20 bps, 0.5% is 50 bps, and 1% is 100 bps. For exact-input swaps, the minimum output is approximately quoted output × (1 − tolerance); if there are multiple independently protected legs, multiply the retained fractions. Treat these as decision ranges, not guarantees of execution quality.
What should I check before sending the source transaction?
First, compare the destination amount with a fresh market quote for the same asset pair and size. Separate expected price impact from the slippage allowance, and check whether the quote states a minimum destination output, a quote expiry, or separate swap-step limits. A minimum output is the enforceable floor; a displayed estimate alone may not be.
Second, account for the time between source confirmation and destination execution. The destination swap can face a different market by the time the bridge completes, so a quote that was safe at submission may fail later. On some routes, the transfer can complete even if the destination swap cannot; the asset may arrive unswapped or require a recovery path, depending on the route. Confirm what the route says happens on that failure before approving it.
For your next transfer, record the quoted destination amount, each swap’s tolerance or minimum output, and the bridge’s separate delivery terms. If you cannot identify which step a tolerance protects, do not infer that it is an end-to-end loss limit; use a route whose execution conditions you can verify.
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