Portfolio managers concentrate their efforts on achieving the best possible trade-off between risk and return. For portfolios constructed from a fixed set of assets, the risk/return profile varies with the portfolio composition. Portfolios that maximize the return, given the risk, or, conversely, minimize the risk for the given return, are called optimal. Optimal portfolios define a line in the risk/return plane called the efficient frontier.
A portfolio may also have to meet additional requirements to be considered. Different investors have different levels of risk tolerance. Selecting the adequate portfolio for a particular investor is a difficult process. The portfolio manager can hedge the risk related to a particular portfolio along the efficient frontier with partial investment in risk-free assets. The definition of the capital allocation line, and finding where the final portfolio falls on this line, if at all, is a function of:
The risk/return profile of each asset
The risk-free rate
The borrowing rate
The degree of risk aversion characterizing an investor
Financial Toolbox™ software includes a set of portfolio optimization functions designed to find the portfolio that best meets investor requirements.