Risk-Return Optimization Flashcards
(10 cards)
Portfolio expected return formula
E[r] = wᵀ·μ (weighted average of asset returns)
Portfolio variance formula
Var(r) = wᵀ·V·w (weights and asset covariances)
Mean-variance optimization goal
Minimize ½ wᵀ·V·w subject to E[r] ≥ α and Σw = 1
First-order condition in MV
V·w* = λ₁·μ + λ₂·1 (trade-off of risk and return)
Closed-form MV weights
w* = λ₁ V⁻¹μ + λ₂ V⁻¹1 with λ from a 2×2 system
Coherent risk measure axioms
Monotonicity, Subadditivity, Homogeneity, Certainty invariance
Capital Market Line (CML)
Return = r_f + θ(α − r_f), Risk = θ·σ*
Sharpe ratio
(E[r] − r_f) / σ(r) (reward per unit risk)
Value-at-Risk (VaR)
Loss quantile at confidence β; not subadditive
Expected Shortfall (ES)
Average loss beyond VaR at confidence β; coherent