Pro-Rata Order Matching

Mechanism

Pro-rata order matching is a rule where, if multiple orders exist at the best available price, they are filled proportionally based on their size relative to the total quantity at that price level. This mechanism differs from price-time priority, which fills the oldest order first. It ensures that all participants offering liquidity at the best price receive a partial fill, rather than only the earliest submitters. This approach distributes fills more broadly.