Order Amendments Need a Queue-Priority Assumption

Queue position affects the probability and timing of a passive fill. We would evaluate an amendment as a new execution decision whenever priority retention lacks explicit support. HyperCore documents price-time matching. The inspected order-book page establishes that ordering principle, while its amendment discussion does not establish every size-change priority rule. A connector should preserve that uncertainty.

Changing a quote changes its waiting economics

Illustrative case: an agent has a 2-unit bid at $99, with 8 units ahead of it. Another trader adds 5 units behind. If a size increase places the modified order at the back, the queue ahead becomes 13 units. If priority is retained, 8 remain ahead. A subsequent 9-unit sell would reach the agent in the retained-priority scenario and leave it untouched in the reset scenario. These are hypothetical queue paths, not observations from Hyperliquid.

Evaluate the amendment against staying still

Save old and new order identifiers, timestamps, prices and sizes. Attribute any priority claim to venue documentation or a controlled observation with the relevant account and order type. Until that evidence exists, calculate waiting outcomes under both retention and reset assumptions. The agent’s rationale should identify the benefit of the new quote and the possible queue cost. A replay can hold incoming flow fixed and compare unchanged, repriced and resized orders without asserting that an aggregated public book reveals an individual order’s exact position.

Measure the decision separately

Use exchange-specific tests for each amendment family rather than extrapolating from one repricing observation to every size adjustment. Aggregated depth may reveal total quantity at a price without revealing individual priority. The audit should distinguish directly observed amendment behavior, documented rules and the hypothetical assumptions used for waiting-cost analysis. That distinction changes which conclusion a future strategy comparison can support.

Our execution and reconciliation framework provides the broader mandate-to-outcome trace. The state and memory contract explains how the verified result should enter the next decision. These notes narrow those published methods to one execution boundary; the worked amounts above are illustrative and the test is a proposed local fixture. The source inspected for the venue-specific statements is the official HyperCore order book.

A smaller queue ahead is only one execution consideration. Repricing can also change adverse selection and the chance of remaining unfilled. Measure these outcomes with the same incoming-flow assumptions before recommending an amendment policy.