Jungmeister, Walter-AlexanderTuro, D.Treemap visualization techniques are extended and applied to stock market portfolios via a prototype application. Designed to facilitate financial decision-making, the prototype provides an overview of large amounts of hierarchical financial data and allows users to alter aspects of the visual display dynamically. Treemap concepts are illustrated via examples which address common portfolio management needs.en-USuser interfacesvisualizationtreemap,Technical Report