in one aspect , the invention comprises acquiring background data regarding securities positions and regarding real - time pricing data ; performing calculations regarding intermediate measures of performance of the securities ; receiving configuration data for a portfolio of securities and one or more data requests , at least one of the data requests comprising a request for a value at risk report regarding the portfolio ; and providing a value at risk report based on a parkinson &# 39 ; s volatility estimation . in another aspect , the invention comprises displaying a tree structure display in a first portion of a graphical user interface display ; in response to a user selecting an item from the tree structure display , displaying a corresponding listing in a tabular display in a second portion of the graphical user interface display ; and in response to the user selecting a listing in the tabular display , displaying a corresponding item in the tree structure display .