Effective trade date August 11, 2025, subject to regulatory review, all Cboe-affiliated U.S. Options Exchanges will modify the opening mechanism for proprietary classes, excluding the VSA constituent series, to include a force open timer.
The timer will force series to open after a configurable period of waiting for a valid width composite market.
This new functionality applies to Regular Trading Hours and Global Trading Hours and for simple instruments only; the opening mechanism for complex instruments will not be changed.
Additionally, the Forced Open Cancel Instruction port attribute can be used to define the default order behavior if a series with resting orders is forced open.
No opening auction will be conducted in series with a forced open. Orders that are not cancelled will be rolled into the book in time priority and processed subject to normal order handling based on order instructions and the NBBO at the time. Orders that opt to be cancelled in the event of a forced opening will receive a cancellation for “N” (No Liquidity).
