Cboe Options Exchanges to Introduce Enhanced Optional Risk Controls

Effective April 20, 2026, all Cboe-affiliated U.S. Options Exchanges will introduce optional enhancements to post-trade risk limit controls for Trading Permit Holders and members. The new features allow firms to optionally exclude auction volume from risk calculations and specify a percentage of trade volume to be counted based on contra-capacity.

A new Atomic EFID/EFID Group Limits feature will enable risk limit breaches to be processed immediately by the triggering matching engine. These controls can be configured via the Customer Web Portal and the Cboe Titanium U.S. Secure Web API.

The updates include three key specifications. Contra-Capacity Fractions allow firms to set a fractional value between 0.0 and 1.0 for trade accumulation, with a default of 1.0. The Exclude Auction Volume feature lets firms omit auction trades from limits, with inclusion as the default. The Atomic EFID/EFID Group Limits feature ensures immediate processing of risk trips within a single engine for enabled firms, whereas non-users will continue with non-atomic, external calculations.

Testing for these enhancements will be available in all Cboe certification environments starting March 30, 2026.