GulfBase Live Support
Leave a message and our representative will contact you soon
Section: 2 Mean-Variance Analysis and Diversification
In mean-variance analysis, we use the expected returns, variances, and co-variances of individual investment opportunity returns to analyzing the risk-return trade-off of combinations, or portfolios, of these individual investments. The assumptions of mean-variance analysis are:
I. Expected Return: The expected return on a portfolio of two assets is simply the weighted average of the returns on the individual assets, weighted by their portfolio weights:
E(Rp) | = | W1E(R1) + W2E(R2) |
Where: | ||
E(Rp) | = | Expected return on portfolio |
E(R1) | = | Expected return on asset 1 |
E(R2) | = | Expected return on asset 2 |
W1 | = | Percentage of total portfolio value invested in asset 1 |
W2 | = | Percentage of total portfolio value invested in asset 2 |
II. Standard Deviation: The standard deviation of a portfolio of two assets is not a simple weighted average of the asset standard deviation; it is also a function of the correlation between the returns of the two assets:
σp | = | [W12 σ12 + W22 σ22 + 2W1W2p 12 σ1 σ2] |
Where: |
||
σ1 | = | Standard Deviation of the expected return on asset 1 |
σ2 | = | Standard Deviation of the expected return on asset 2 |
ρ12 | = | Correlation between the expected returns on assets 1&2 |
III. Correlation: Correlation can be defined as the percentage of variability in one variable (dependent variable) that is explained by another variable (independent variable). It is calculated as:
Corr (Ri, Rj) | = | Covariance (Ri, Rj) |
σ(Ri) σ(Rj) |