Which factor determines the execution priority for SwissAtMid orders?

Which factor determines the execution priority for SwissAtMid orders?

• A. Quantity-time priority
• B. Price-time priority
• C. Time-only priority
• D. Pro-rata allocation

Answer: (B)

Price-time priority means the best price gets execution first, and among orders at that same price, the oldest order is filled first. For SwissAtMid orders, the price component determines who gets matched, and when multiple orders offer the same mid-price, the one that arrived earliest has priority. This reflects standard market behavior: prioritize value (better price) and then fairness by time. Time-only priority would ignore price differences, and pro-rata would allocate by size among same-priced orders rather than giving strict oldest-first preference, which is not how SwissAtMid is executed.

Price-time priority means the best price gets execution first, and among orders at that same price, the oldest order is filled first. For SwissAtMid orders, the price component determines who gets matched, and when multiple orders offer the same mid-price, the one that arrived earliest has priority. This reflects standard market behavior: prioritize value (better price) and then fairness by time. Time-only priority would ignore price differences, and pro-rata would allocate by size among same-priced orders rather than giving strict oldest-first preference, which is not how SwissAtMid is executed.