According to the principle of highest volume transacted, exchange prices must be determined such that the highest possible volume of shares will change hands.
The principle of highest volume transacted applies to the procedures for determining the single cash price, the opening price, and the closing price in the cash market, as well as to the auctions in the electronic trading system. After buy and sell orders have been entered into the order book and matched, the Xetra Frankfurt Specialist (or the electronic trading system) determines the price that will maximise share turnover.
In this example, the greatest number of shares will change hands at a price of euro 135. All market orders, all buy orders with a limit above the determined price and all sell orders with a limit below the determined price are executed. Moreover, all sell orders with a limit at the exchange price are executed, whereas buy orders with a limit at the exchange price are executed only in part. Because there is still supply for the stock at a price of euro 135, the price addendum bB, or "bezahlt Brief" is used.
