Efficient Frontier
Set of optimal portfolios offering highest expected return for each level of portfolio risk.
FAQs
What does it mean for a portfolio to be 'on' the efficient frontier?
A portfolio on the efficient frontier is optimal—no other combination of assets can deliver higher expected return at the same risk level, or lower risk for the same expected return. Moving off the frontier means accepting an inferior risk-return tradeoff.
How does diversification affect the efficient frontier?
Adding assets with low or negative correlations to each other expands the efficient frontier outward (higher return) and leftward (lower risk). Diversification is the key mechanism by which the frontier improves, as imperfectly correlated assets reduce portfolio volatility without sacrificing expected return.
What is the main practical limitation of efficient frontier analysis?
The efficient frontier is extremely sensitive to input assumptions. Small errors in estimated expected returns or correlations can cause portfolio weights to shift dramatically. This 'error maximization' problem means real-world portfolios built on raw historical estimates often perform poorly out of sample.
Related Terms
Modern Portfolio Theory
Framework for constructing investment portfolios to maximize return for a given level of risk.
Sharpe Ratio
Risk-adjusted return metric measuring excess return earned per unit of total volatility.
Capital Asset Pricing Model
Model describing relationship between systematic risk and expected return for assets in equilibrium.
Monte Carlo Simulation
Computational technique using random sampling to model probability distributions of financial outcomes.