The accumulated total open position is equal to the sum of all foreign currency long positions and short positions, so item A is correct; The total position reflects the foreign exchange risk of the entire currency portfolio, so item B is correct; The total position calculated by short-side method is equal to the larger sum of net long position and net short position, so item D is correct; The net total open position is equal to the difference between all foreign currency long positions and short positions, so item C is incorrect.