Responding to COA Orders

Customers may interact with a COA with either a Response Order or a regular complex order resting on the book at the completion time of the COA. Response Orders must be priced equal to or more aggressive than the auction price and include a valid AuctionID (9370) of the targeted auction for the Response Order to interact with the COA. Response Orders priced less aggressive than the auction price will be held and canceled at the end of the auction period.

A customer may submit multiple responses to the same COA priced at increments of $0.01.

Response orders priced equal to or more aggressive than the auction price will be held for the duration of the exposure period and continue to be eligible for execution until the COA either fully executes or terminates early. Response Orders may be cancelled or modified anytime.

Response orders not fully executed against the targeted COA order will be cancelled back following the conclusion of the auction.

At the conclusion of an auction response or exposure period, the Matching Engine will continue processing messages, including auction responses, for up to an additional 100ms (900ms on C1 only) to include auction responses that arrived at the Matching Engine NIC prior to the scheduled auction end time. The Matching Engine will immediately conclude the auction either upon processing all events arriving at the Matching Engine prior to the scheduled auction end time or upon elapse of the additional timer.

For details on responding to COAs of a Complex order with a stock leg, please see Complex Orders with Stock Legs (C1 and EDGX only).