Chapter 6: The Meaning and Measurement of Risk and Return Flashcards
Define and measure the expected rate of return of an individual investment.
When we speak of “returns” on an investment, either we are talking about historical return, what we earned on an investment in the past, or expected returns, where we are attempting to determine the return we can “expect” to receive in the future. In a world of uncertainty, we cannot make forecasts with certitude. Thus, we must speak in terms of expected events. The expected return on an investment may therefore be stated as a weighted average of all possible returns, weighted by the probability that each will occur.
Holding-Period Return (Historical or Realized Rate of Return)
The rate of return earned on an investment, which equals the dollar gain divided by the amount invested.
Expected Rate of Return
The arithmetic mean or average of all possible outcomes where those outcomes are weighted by the probability that each will occur.
Holding-Period Dollar Gain (DG) Equation
Price at end of period + Cash distribution (ie. dividend) - Price at beginning of period.
Holding-Period Rate of Return (r) Equation
Dollar Gain/Price at the beginning of period = (Price at end of period + Dividend - Price at beginning of period)/Price at beginning of period
Expected Cash Flow (CF-bar)
(Cash flow in state 1 (i.e. CF1) x Probability of state 1 (i.e. Pb1)) + (Cash flow in state 2 (i.e. CF2) x Probability of state 2 (i.e. Pb2)) + . . . + (Cash flow in state n (i.e. CFn) x Probability of state n (i.e. Pbn))
Expected Rate of Return (r-bar)
(Rate of return for state 1 (i.e. r1) x Probability of state 1 (i.e. Pb1)) + (Rate of return for state 2 (i.e. r2) x Probability of state 2 (i.e. Pb2)) + . . . + (Rate of return for state n (i.e. rn) x Probability of state n (i.e. Pbn))
Define and measure the riskiness of an individual investment.
Risk associated with a single investment is the variability of cash flows or returns and can be measured by the standard deviation.
Risk
Potential variability in future cash flows.
Standard Deviation
A statistical measure of the spread of a probability distribution calculated by squaring the difference between each outcome and its expected value, weighting each value by its probability, summing over all possible outcomes, and taking the square root of this sum.
Variance in Rates of Return (σ2)
[(Rate of return for state 1 (i.e. r1) - Expected rate of return (i.e. r-bar))^2 x Probability of state 1 (pb1)] + [(Rate of return for state 2 (i.e. r2) - Expected rate of return (i.e. r-bar))^2 x Probability of state 2 (pb2)] + . . . + [(Rate of return for state n (i.e. rn) - Expected rate of return (i.e. r-bar))^2 x Probability of state n (pbn)]
Compare the historical relationship between risk and rates of return in the capital markets.
Ibbotson Associates have provided us with annual rates of return earned on different types of security investments as far back as 1926. They summarize among other things, the annual returns for six portfolios of securities made up of :
1. Common stock of large companies
2. Common stock of small firms
3. Long-term corporate bonds
4. Long-term U.S. government bonds
5. Intermediate-term U.S. government bonds
6. U.S. Treasury bills
A comparison of the annual rates of return for these respective portfolios for the years 1926 to 2011 shows a positive relationship between risk and return, with Treasury bills being least risky and common stocks of small firms being most risky. From the data, we are able to see the benefit of diversification in terms of improving the return-risk relationship. Also, the data clearly demonstrate that only common stock has in the long run served as an inflation hedge, and that the risk associated with common stock can be reduced if investors are patient in receiving their returns.
Explain how diversifying investments affects the riskiness and expected rate of return of a portfolio or combination of assets.
We made an important distinction between nondiversifiable risk and diversifiable risk. We concluded that the only relevant risk, given the opportunity to diversify out portfolio, is a security’s nondiversifiable risk, which we called by two other names: systematic risk and market-related risk.
Systematic Risk (Market Risk or Nondiversifiable Risk)
- The risk related to an investment return that cannot be related to an investment return that cannot be eliminated through diversification. Systematic risk results from factors that affect all stocks. Also called market risk or nondiversifiable risk.
- The risk of a project from the viewpoint of a well-diversified shareholder. This measure takes into account that some of the project’s risk will be diversified away as the project is combined with the firm’s other projects, and, in addition, some of the remaining risk will be diversified away by shareholders as they combine this stock with other stocks in their portfolios.
Unsystematic Risk (Company Unique Risk or Diversifiable Risk)
The risk related to an investment return that can be eliminated through diversification. Unsystematic risk is the result of factors that are unique to the particular firm. Also called company-unique risk or diversifiable risk.
Characteristic Line
The line of “best fit” through a series of returns for a firm’s stock relative to the market’s returns. The slope of the line, frequently called beta, represents the average movement of the firm’s stock returns in response to a movement in the market’s returns.
Beta
The relationship between an investment’s returns and the market’s returns. This is a measure of the investment’s nondiversifiable risk.