The disclosed embodiments generally relate to a slicer order quantity reduction tool. An example method for reducing a quantity of a slicer order includes calculating a collective quantity associated with available ones of a plurality of child orders; comparing the collective quantity and a reduction amount received in connection with a quantity reduction request for the slicer order; and determining, when the comparison indicates that the available ones of the child orders have insufficient quantity to meet the reduction amount, whether inflight ones of the plurality of child orders collectively have sufficient quantity to make up a shortfall of the available ones of the child orders.