During the opening phase, a call auction is carried out for each security separately. At its conclusion, each security’s price is set. This is the opening price, at which transactions based on orders submitted during the pre-opening phase are performed. This trading phase lasts just a few seconds. The opening price and turnover are calculated for each security separately, in a random order.

A security’s opening price is the price at which the cumulative supply and demand curves intersect, and at which the largest turnover is achieved. If maximum turnover is achieved at several prices, the opening price is set at the price closest to the base price, regardless of the trend. There are three cases in which the opening price is set at the base price, and the opening turnover is zero:

• No orders were submitted for the security
• All of the orders submitted were supply orders only or demand orders only
• Both supply and demand orders were submitted, but there is no price intersection

Order priorities are determined by the price limit (first priority) and the time (second priority). Orders that can be executed during the opening phase are sell orders with a price limit lower than or equal to the opening price, and buy orders with a price limit higher than or equal to the opening price. Due to the order priorities, some of these orders may not be executed.

In Limit (LMT) type orders that are not executed, or are partially executed, during the opening phase, the remaining part is automatically transferred to the continuous trading phase, at the original price limit and time priority. In Limit Opening (LMO) type orders that are not executed, or are partially executed, during the opening phase, the remaining part is cancelled and deleted from the books.

During the opening phase of a particular security, orders for that security cannot be added, changed or cancelled.

The maximum price fluctuation for bonds and T-bills during this phase is ±6%.