A pool's spot price can disagree with your reference market

A pool can start at a different price from your chosen reference. The requested trade then moves along the pool's curve from that starting point. Separate the initial gap from the trade's own size effect before interpreting an impact percentage.

One quote, two benchmarks

Assume a hypothetical pool's local rate is 1.05 output tokens per input, while an external reference uses 1.00. A 100-input trade returns 104 output tokens after the quote's stated deductions.

Relative to the local-rate extrapolation of 105, the quote is about 0.952381% lower. Relative to the external reference of 100, it is 4% higher. Those results are compatible because the benchmarks differ.

Do not assume either reference is universally correct

The local price may reflect temporary pool imbalance, while the external reference may be stale, come from another asset representation or describe a very small trade. Investigate the identity, timing and executable size behind each.

Uniswap's pricing documentation distinguishes reserve-based pricing from an external reference used to evaluate the offered exchange. A reserve ratio alone does not establish the wider market's fair executable price.

Use the gap to ask a narrower question

For pool mechanics, measure the requested trade relative to the pool's starting local price. For economic comparison, evaluate it against a contemporaneous alternative or clearly stated reference. For total user cost, include separate payments afterward.

A favorable benchmark gap does not guarantee a realizable arbitrage. The other side of a proposed trade, its size, fees and state changes still matter. Preserve both references and the final quote rather than selecting whichever benchmark makes the route look better. The goal is to show why an impact statistic and a cross-market comparison can reach different conclusions about the same receiving amount.