One embodiment of the present invention relates to securities trading using electronic systems. Another embodiment of the present invention relates to a computer implemented trade execution method, comprising: sending from an execution venue to each of a plurality of smart order routers a notification message; receiving at each of the smart order routers the notification message sent thereto, wherein the notification message notifies each of the smart order routers about the presence of a non-displayed priced order at the execution venue; sending from at least one of the smart order routers to the execution venue at least one order to execute against the non-displayed priced order; receiving at the execution venue each order sent from each of the smart order routers; and executing at least one order received from at least one of the smart order routers against the non-displayed priced order.