1. A computer system comprising one or more processors programmed to: (a) transmit data sufficient to describe a graphical user interface to be displayed to a user, said graphical user interface comprising one or more icons, at least one of said one or more icons representing an algorithm switching engine; and (b) receive data indicating an algorithm switching engine to be used to execute a securities trade order, wherein said user has designated said algorithm switching engine by dragging a securities symbol over an icon corresponding to said algorithm switching engine.