Order Matching

A market buy for two contracts is matched against the first available sell order in the book. The matching algorithm processes aggressive orders using a first-in-first-out system. Incoming orders are matched with existing book orders in the order those existing orders were posted. A first-in-first-out matching algorithm processes market taker orders by pairing them with the earliest available counterpart orders. If quantity at the best price is insufficient, the algorithm fills what it can there and then moves to the next price level. The matched trade price becomes the new market price. If an order is larger than available quantity at the best price, the remainder is filled at the next price level. The execution price of a matched order becomes the new market price and appears on the chart. A market buy order is matched against the first sell orders available at the best price.