What is capital allocation line?

The capital allocation line (CAL) represents the risk-return trade-off of a portfolio that combines a risk-free asset and a risky asset or portfolio of assets. It is a graphical line that shows the expected return of a portfolio against its risk, measured by standard deviation. The slope of the CAL indicates the risk premium per unit of risk, helping investors determine the optimal mix of risk-free and risky investments to achieve their desired return. The point where the CAL is tangent to the efficient frontier represents the optimal risky portfolio.