Investors exhibit behavioral biases when they construct portfolios in layers, comprising a pyramid with each layer having a specific purpose in achieving a different goal. This is also referred to as mental accounting because the assets in each layer of the pyramid are viewed separately from each other with no regard to how they are correlated. In the pyramid structure, the most pressing goals are placed on the bottom layer and are met using low-risk, conservative investments. Each successive layer going toward the top of the pyramid is comprised of riskier assets to accomplish less immediate or less important goals. In the pyramid approach, investors see each layer as having a separate level of risk. Advisers with clients who view their portfolios in layered pyramids can help them understand which mental accounts they have and the risk the client is assigning to each account.

This is in contrast to traditional finance theory, which constructs a portfolio based on viewing the assets as working together as one unit, taking into consideration the correlation between those assets. In this scenario, the portfolio is viewed as having a single measure of risk.