Abstract: A transaction management device of executing plural if-done-orders in parallel. An order information generation unit of the device generates plural order information groups each including a first order for placing one of a buy or sell orders at a first order price, a second order for placing the other of these orders at a second order price, and a stop loss order for placing the other of these orders at a stop loss order price. This unit acquires the upper limit price for transactions, the lower limit price for transactions, and the number of simultaneously generated order information groups, and calculates the first and second order prices in such a manner that the price difference between the first orders is constant, the price difference between the second orders is constant, and the price difference between the first and the second orders belonging to the same group is constant.