New metrics are provided for evaluating a portfolio of financial assets and/or for determining whether or not the portfolio is properly tracking the performance of a desired index. The technique involves calculating a correlative value for the portfolio relative to each of a number of different factors having data values that are likely to be correlated with an aggregate market value for the portfolio, where the correlative value for an item relative to a given factor is a measure of a tendency of the aggregate market value of the item to change based on a change in the data value for such factor (e.g., in the nature of a sensitivity or elasticity). Such metrics often can be used, according to the present invention, in conjunction with other information to facilitate the adjustment of the portfolio to more closely track the performance of the desired index.