Limit Order Hierarchy

Algorithm

A limit order hierarchy, within electronic exchanges, defines the precedence rules governing the execution of competing limit orders at the same price level. This prioritization is crucial for order execution quality, particularly in high-frequency trading environments where multiple orders can arrive simultaneously. Exchanges employ varied algorithms, often prioritizing time priority—first-in, first-out—but may also incorporate pro-rata allocation or price-time priority to manage order flow efficiently. Consequently, understanding these algorithms is essential for traders seeking optimal fill rates and minimizing adverse selection.