Abstract: In one aspect, the invention comprises a computer system comprising: (a) a computer component that receives data identifying a person's investing goals, current savings, and risk tolerance; (b) a database that stores the data identifying a person's investing goals, current savings, and risk tolerance and further stores data describing margin rates, stock returns, and bond returns; (c) a computer component that calculates a utility function and identifies a probability distribution of returns that is most optimal for the person, based on the data identifying the person's investing goals and risk tolerance; and (d) a computer component that calculates one or more investment targets for the person based on application of the utility function to the data describing margin rates, stock returns, and bond returns. Other aspects and embodiments of the invention comprise related methods and software.