Even in case of not matching at prices inside executable price range, execution processing is conducted at upper/lower limit of executable price range in arrowhead4.0, called "Special Execution". (In case of matching at upper/lower daily limit prices, orders are executed by Stop Allocation method in the same way as now.)
"Special Execution" is different from Stop Allocation method and is conducted based on time priority for the orders at the upper/lower limit of executable price range and outside executable price range.