On 6 February 2023, Cboe BYX proposed to amend priority for position changes.
- Cboe BYX, EDGA, BZX, EDGX proposed to amend time priority for position changes.
- Provisions specified that certain changes in position will result in a loss of time priority.
- Proposal is substantially similar to MIAX timestamp short sell amendments.
- Orders may be modified from sell long to sell short exempt (or vice versa) or sell short exempt to sell short (or vice versa) using a replace message (Cboe BYX Rule 11.19).
- Change in position will result in a loss of time priority if made when a Short sale circuit breaker (SSCB) pursuant to Rule 201 of Regulation SHO (17 CFR 242.201) is in effect.
- Short sale orders entered with an order instruction to post to an away trading center when an SSCB is in effect are eligible for routing by exchange (Cboe BYX Rule 11.13).