Effective trade date April 20, 2026, all Cboe-affiliated U.S. Options Exchanges will allow Trading Permit Holders (TPHs)/Members to optionally specify whether auction volume is excluded in post-trade risk controls.

TPHs/Members may also optionally specify a percentage of trade volume or count to be accumulated to the underlying counters based on contra-capacity.

Additionally, an optional Atomic EFID/EFID Group Limits feature will be available to allow EFID or EFID group risk trips to be processed immediately by the tripping Matching Engine.

Upon the effective date, all Cboe-affiliated U.S. Options Exchanges will allow TPHs/Members to optionally set risk limit controls for Contra-Capacity Fractions and Exclude Auction Volume. These limits can be configured in the Customer Web Portal and the Cboe Titanium U.S. Secure Web API.

Additionally, upon the effective date, for firms having the Atomic EFID/EFID Group Limits feature enabled, if a trip for an EFID or EFID group occurs in a single Matching Engine, the risk trip will be processed immediately by that Matching Engine and subsequently at slightly later times across all other Matching Engines.

Risk Management Specification Updates

Contra-Capacity Fractions

• Allows firms to specify that a fractional amount of trade volume or count is to be accumulated to the underlying counters based on contra-capacity.
• Firms can optionally specify fractions by contra-capacity, specified as values between and including 0.0 to 1.0. Firms not using this functionality will use the default value of 1.0.

Exclude Auction Volume

• Allows firms to exclude auction volume from risk limits.
• If firms do not utilize this functionality, auction volume will be included by default.

Atomic EFID/EFID Group Limits

• Allows firms to enable atomic EFID or EFID group risk trips
• If firms do not utilize this functionality, EFID and EFID group risk trips will continue to be calculated and will occur in a non-atomic manner using an application outside of the Matching Engine.

This functionality will be available for testing in all Cboe-affiliated U.S. Options Exchanges certification environments on March 30, 2026.