We provide complete source code for a front-end GUI and its back-end counterpart for a stock market visualization tool. It is built based on the “functional visualization” concept we discuss, whereby functionality is not sacrificed for fancy graphics. The GUI, among other things, displays a color-coded signal (computed by the back-end code) based on how “out-of-whack” each stock is trading compared with its peers (“mean-reversion”), and the most sizable changes in the signal (“momentum”). The GU