5. Jack and Jill, two finance majors, were arguing over whether to use standard deviation or variance
when discussing a stock’s monthly returns. Jack claimed variance was more appropriate, but Jill
thought standard deviation made more sense. Jack and Jill went up to Ms. Hill who sided with Jill,
offering the following support:
variance involves only those returns which fall below expected returns
standard deviation provides a measure of dispersion in the same units as expected returns
compared to variance, standard deviation focuses more on bad outcomes, which are the
primary concern of risk averse investors
variance is more difficult to calculate than standard deviation
standard deviation equals the expected value of squared deviations from the mean, which
is more intuitive than variance
6. If an investor holds all of her wealth in a single asset, the most appropriate measure for finding the risk
of that asset would be:
the correlation coefficient of the asset
the average arithmetic expected return found from an historical sample of data
the variance (or its square root, the standard deviation) of returns for the asset
the covariance between the asset and the market portfolio
the beta of the particular asset
7. Which statement is false?
If two assets tend to move together, the covariance between the assets will be positive.
The correlation coefficient is a unit-free measure of co-movements between two assets,
with a range between -1.0 and 1.0.
When two assets held in a portfolio move independently, both the covariance and
correlation coefficient of these assets will be zero.
Covariance is important when evaluating the risk of a portfolio because it is a measure of
the co-movements between assets in the portfolio.
The weaker the correlation between two assets, the smaller the reduction of risk attainable
by holding positive amounts of these assets in a portfolio.
8. Shiann holds an equally weighted portfolio of ten oil stocks. Recently, she received a large inheritance
and decided to purchase ten very volatile stocks in a variety of industries. Assuming the portfolio
remained equally weighted, adding these securities would:
increase the unsystematic risk associated with the portfolio
increase the portfolio’s variance
decrease the portfolio’s variance
decrease the impact of covariance in the portfolio
decrease the systematic risk associated with the portfolio
9. Undiversified portfolios are suboptimal because:
they eliminate returns from risks that are common across all types of securities
they do not offer higher returns even though they expose investors to unsystematic risk
they eliminate unsystematic risk and therefore provide lower expected returns
they expose investors to market risk without any increase in expected returns