Introduction

The Cboe-affiliated U.S. Options Exchanges offer customers the ability to queue orders during the pre-market and regulatory halt periods (Queuing Period), after which the Opening Process matches crossable interest at a designated Opening Price and transitions to normal trading.

The BZX Options (BZX), Cboe Options (C1), C2 Options (C2), and EDGX Options (EDGX) Exchanges use a Price Forming Opening Process where opening prices are determined through a matched contracts maximizing and imbalance minimizing process that is collared by external markets for series for which external markets exist.

A distinct Opening Process applies to Complex instruments on all Cboe-affiliated Options Exchanges. Complex instruments open/re-open in a process dependent on the state of the constituent Single Leg Books. Specifically, Complex instruments open/re-open when all constituent Single Leg books transition to the open state and the Complex book opening price is within the synthetic best bid / best offer range formed from the Single Leg book markets. See the Cboe Titanium U.S. Options Complex Book Process for more detail on the Complex Instruments opening process.