Question 284  covariance, correlation

The following table shows a sample of historical total returns of shares in two different companies A and B.

Stock Returns
Total effective annual returns
Year	##r_A##	##r_B##
2007	0.2	0.4
2008	0.04	-0.2
2009	-0.1	-0.3
2010	0.18	0.5

What is the historical sample covariance (##\hat{\sigma}_{A,B}##) and correlation (##\rho_{A,B}##) of stock A and B's total effective annual returns?

(a) 0.05696, 0.702247

(b) 0.05696, 0.238663

(c) 0.053333, 0.936329

(d) 0.040889, 0.930519

(e) 0.04, 0.930519

Question 236  diversification, correlation, risk

Diversification in a portfolio of two assets works best when the correlation between their returns is:

(a) -1

(b) -0.5

(c) 0

(d) 0.5

(e) 1

Question 81  risk, correlation, diversification

Stock A and B's returns have a correlation of 0.3. Which statement is NOT correct?

(a) If stock A's return increases, stock B's return is also expected to increase.

(b) If stock A's return decreases, stock B's return is also expected to decrease.

(c) If stock A and B were combined in a portfolio, there would be no diversification at all since they are positively correlated.

(d) Stock A and B's returns have positive covariance.

(e) a and b.

Question 111  portfolio risk, correlation

All things remaining equal, the variance of a portfolio of two positively-weighted stocks rises as:

(a) The correlation between the stocks' returns rise.

(b) The correlation between the stocks' returns decline.

(c) The portfolio standard deviation declines.

(d) Both stocks' individual variances decline.

(e) Both stocks' individual standard deviations decline.

Question 82  portfolio return

Portfolio Details
Stock	Expected return	Standard deviation	Correlation	Dollars invested
A	0.1	0.4	0.5	60
B	0.2	0.6		140

What is the expected return of the above portfolio?

(a) 0.15

(b) 0.17

(c) 0.1908

(d) 0.2412

(e) 0.34

Question 83  portfolio risk, standard deviation

Portfolio Details
Stock	Expected return	Standard deviation	Correlation ##(\rho_{A,B})##	Dollars invested
A	0.1	0.4	0.5	60
B	0.2	0.6		140

What is the standard deviation (not variance) of returns of the above portfolio?

(a) 0.4368

(b) 0.4911

(c) 0.6331

(d) 0.6564

(e) 0.7348

Question 73  portfolio risk, standard deviation

Portfolio Details
Stock	Expected return	Standard deviation	Covariance ##(\sigma_{A,B})##	Beta	Dollars invested
A	0.2	0.4	0.12	0.5	40
B	0.3	0.8		1.5	80

What is the standard deviation (not variance) of the above portfolio? Note that the stocks' covariance is given, not correlation.

(a) 0.5497

(b) 0.5651

(c) 0.5963

(d) 0.6156

(e) 0.8165

Question 283  portfolio risk, correlation, needs refinement

Three important classes of investable risky assets are:

• Corporate debt which has low total risk,
• Real estate which has medium total risk,
• Equity which has high total risk.

Assume that the correlation between total returns on:

• Corporate debt and real estate is 0.1,
• Corporate debt and equity is 0.1,
• Real estate and equity is 0.5.

You are considering investing all of your wealth in one or more of these asset classes. Which portfolio will give the lowest total risk? You are restricted from shorting any of these assets. Disregard returns and the risk-return trade-off, pretend that you are only concerned with minimising risk.

(a) Most money in corporate debt, with some money in equity and real estate.

(b) Most money in equity, with some money in corporate debt and real estate.

(c) Most money in real estate, with some money in corporate debt and equity.

(d) Most money in corporate debt, with some money in real estate and none in equity.

(e) All money in corporate debt.

Question 282  expected and historical returns, income and capital returns

You're the boss of an investment bank's equities research team. Your five analysts are each trying to find the expected total return over the next year of shares in a mining company. The mining firm:

• Is regarded as a mature company since it's quite stable in size and was floated around 30 years ago. It is not a high-growth company;
• Share price is very sensitive to changes in the price of the market portfolio, economic growth, the exchange rate and commodities prices. Due to this, its standard deviation of total returns is much higher than that of the market index;
• Experienced tough times in the last 10 years due to unexpected falls in commodity prices.
• Shares are traded in an active liquid market.

Your team of analysts present their findings, and everyone has different views. While there's no definitive true answer, whose calculation of the expected total return is the most plausible? Assume that:

• The analysts' source data is correct and true, but their inferences might be wrong;
• All returns and yields are given as effective annual nominal rates.

(a) Alice says 5% pa since she calculated that this was the average total yield on government bonds over the last 10 years. She says that this is also the expected total yield implied by current prices on one year government bonds.

(b) Bob says 4% pa since he calculated that this was the average total return on the mining stock over the last 10 years.

(c) Cate says 3% pa since she calculated that this was the average growth rate of the share price over the last 10 years.

(d) Dave says 6% pa since he calculated that this was the average growth rate of the share market price index (not the accumulation index) over the last 10 years.

(e) Eve says 15% pa since she calculated that this was the discount rate implied by the dividend discount model using the current share price, forecast dividend in one year and a 3% growth rate in dividends thereafter, which is the expected long term inflation rate.