Why reaching a limit price may not fill a DEX order

A chart can touch your limit price while your DEX order remains unfilled. The chart reports a market observation. Filling your order requires a compatible executable exchange for its amount, plus valid authorization and a successful fulfillment process.

The observed trade may be much smaller

Suppose a hypothetical chart records one A changing hands at 5 B. Your order offers 1,000 A at that rate. The tiny observation does not prove that buyers or pools can absorb all 1,000 A at 5 B each.

In a pool, the available exchange rate changes with the amount consumed. In an order market, the displayed top level can have limited size. A limit comparison must therefore use executable terms for the required quantity.

Price is only one condition

0x's fill reference lists conditions beyond price, including expiry, prior cancellation, balances, allowances and permitted counterparties. These illustrate why a rate match alone is insufficient.

An executor also needs a feasible settlement. If fulfillment work is uneconomic under the protocol's terms, a barely eligible price may not attract execution. Whether the order allows partial fills can further change what liquidity is usable.

The chart and order may describe different markets

Check the exact token contracts, chain, source and time. A price on another network, a last-trade print, or an aggregated index may not represent the source available to the order. Rounded chart labels can also hide a small difference around the limit.

A useful conceptual check follows this sequence: identify the order's exact conditions; identify what the chart measured; then determine whether the required size was executable under matching conditions. The claim “the chart reached my price” skips the middle work.

None of this proves that an unfilled order is behaving correctly. It explains what evidence is needed before attributing the result to an error. A complete investigation compares the order's eligibility and available settlement at the relevant time rather than relying on a chart screenshot alone.