Pre-opening: Initial Guidance for Participants

Pre-opening offers participants some initial guidance on how an exchange day is developing. Orders and quotes may be entered during this time, and a theoretical opening price is displayed.

Order and quote maintenance during pre-opening

Each exchange day begins with pre-opening, which runs from the start of the exchange day until the opening of the respective trading segment. During this phase, participants may enter or cancel orders and quotes in the order books. Orders and quotes are not executed at this point.

Calculation of the theoretical opening price

Orders and quotes are kept in the order books. A theoretical opening price is calculated on the basis of orders in the order books using the Matching Rules. This theoretical opening price is displayed to participants via the Exchange System as a guide.

Rule regarding duty to trade on the Exchange

During pre-opening, participants have the possibility of reporting off-order book trades. The duty to trade on the Exchange does not apply at this point.

Special case for the Market Maker Book - Fill or Kill: no orders accepted

The Market Maker Book - Fill or Kill (MMB-FOK) market model is a special case: with this model, participants may only enter quotes, but not orders, during pre-opening. If a participant attempts to enter an order, the Exchange System rejects it.