One simple but powerful method investors can use to assess the risk and reward of a stock portfolio is using the Capital Asset Pricing Model, or CAPM, model for expected returns.

If your expected return on the individual investments in your portfolio is known or can be anticipated, you can calculate the portfolio's overall rate of return using Microsoft Excel.

Microsoft Excel, the widely used spreadsheet software, can be helpful for statistical analysis, with its built-in functions and free add-in tools.