As of October 13, 2025, without prejudice to the regulatory review, the exchange of CBOE BZX options will introduce complex orders.
Currently, the CBOE supports complex orders on CBOE (C1), C2 options (C2) and EDGX Options Exchange. At the date of entry into force, without prejudice to the regulatory review, the CBOE will support complex orders in all CBOE -connected options exchanges, including BZX.
Complex orders in BZX will be available for trade through the complex order book (COB) in priority distribution and through the Complex Auction (COA) mechanism, the distribution of pre-righteousness with the functionality of priority bids.
CoA auction messages about BZX options will contain a (zero) price for the price field, which matches behavior in C1 and C2 exchanges.
At the date of entry into force, without prejudice to the Regulatory Review, COA correspondents at the BZX Options Exchange will prioritize the distribution to the size of their bid to the national best offer and offer (NBBO) if they are on Contra NBBO at any feet of the complex instrument at the beginning of the auction.
If the NBBO on multiple feet at the start of the auction, the size of the priority distribution will be based on the larger size of the market manufacturer on any NBBO foot, regardless of the proportions on each foot. At each price level, complex orders and COA answers from priority priorities will first exchange the COA command and the balance of the COA order will be given to the opposite interest in the legs of the feet in priority, then to pre-report priority over other COAs and other compositions.
If multi-priority bids are on the NBBO and the combined size of the answers is greater than the size of the COA order, then priority tenders will receive a share of Pro-Rata based on the size of the priority offers.