Contenu connexe Similaire à Chapter 7 an introduction to risk and return (20) Chapter 7 an introduction to risk and return1. Chapter 7
An Introduction to
Risk and Return
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7-1
2. Calculating the Realized Return from
an Investment
• Realized return or cash return measures
the gain or loss on an investment.
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7-2
3. Calculating the Realized Return from
an Investment (cont.)
• Example 1: You invested in 1 share of
Apple (AAPL) for $95 and sold a year later
for $200. The company did not pay any
dividend during that period. What will be
the cash return on this investment?
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7-3
4. Calculating the Realized Return from
an Investment (cont.)
• Cash Return = $200 + 0 - $95
= $105
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7-4
5. Calculating the Realized Return from
an Investment (cont.)
• We can also calculate the rate of return as
a percentage. It is simply the cash return
divided by the beginning stock price.
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7-5
6. Calculating the Realized Return from
an Investment (cont.)
• Example 2: You invested in 1 share of
share Apple (AAPL) for $95 and sold a year
later for $200. The company did not pay
any dividend during that period. What will
be the rate of return on this investment?
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7-6
7. Calculating the Realized Return from
an Investment (cont.)
• Rate of Return = ($200 + 0 - $95) ÷ 95
= 110.53%
• Table 7-1 has additional examples on measuring an
investor’s realized rate of return from investing in
common stock.
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7-7
9. Calculating the Realized Return from
an Investment (cont.)
• Table 7-1 indicates that the returns from
investing in common stocks can be positive
or negative.
• Furthermore, past performance is not an
indicator of future performance.
• However, in general, we expect to receive
higher returns for assuming more risk.
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7-9
10. Calculating the Expected Return
from an Investment
• Expected return is what you expect to
earn from an investment in the future.
• It is estimated as the average of the
possible returns, where each possible
return is weighted by the probability that it
occurs.
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7-10
11. Calculating the Expected Return
from an Investment (cont.)
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7-11
13. Calculating the Expected Return
from an Investment (cont.)
• Expected Return
= (-10%×0.2) + (12%×0.3) + (22%×0.5)
= 12.6%
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7-13
14. Measuring Risk
• In the example on Table 7-2, the expected
return is 12.6%; however, the return could
range from -10% to +22%.
• This variability in returns can be quantified
by computing the Variance or Standard
Deviation in investment returns.
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7-14
15. Measuring Risk (cont.)
• Standard deviation is given by square root
of the variance and is more commonly
used.
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7-15
16. Calculating the Variance and Standard Deviation
of the Rate of Return on an Investment
• Let us compare two possible investment
alternatives:
– (1) U.S. Treasury Bill – Treasury bill is a short-
term debt obligation of the U.S. Government.
Assume this particular Treasury bill matures in
one year and promises to pay an annual return
of 5%. U.S. Treasury bill is considered risk-
free as there is no risk of default on the
promised payments.
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7-16
17. Calculating the Variance and Standard Deviation
of the Rate of Return on an Investment (cont.)
– (2) Common stock of the Ace Publishing
Company – an investment in common stock will
be a risky investment.
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7-17
18. Calculating the Variance and Standard Deviation
of the Rate of Return on an Investment (cont.)
• The probability distribution of an
investment’s return contains all possible
rates of return from the investment along
with the associated probabilities for each
outcome.
• Figure 7-1 contains a probability
distribution for U.S. Treasury bill and Ace
Publishing Company common stock.
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7-18
20. Calculating the Variance and Standard Deviation
of the Rate of Return on an Investment (cont.)
• The probability distribution for Treasury bill
is a single spike at 5% rate of return
indicating that there is 100% probability
that you will earn 5% rate of return.
• The probability distribution for Ace
Publishing company stock includes returns
ranging from -10% to 40% suggesting the
stock is a risky investment.
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7-20
21. Calculating the Variance and Standard Deviation
of the Rate of Return on an Investment (cont.)
• Using equation 7-3, we can calculate the
expected return on the stock to be 15%
while the expected return on Treasury bill
is always 5%.
• Does the higher return of stock make it a
better investment? Not necessarily, we
also need to know the risk in both the
investments.
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7-21
22. Calculating the Variance and Standard Deviation
of the Rate of Return on an Investment (cont.)
• We can measure the risk of an investment
by computing the variance as follows:
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7-22
24. Calculating the Variance and Standard Deviation
of the Rate of Return on an Investment (cont.)
Investment Expected Standard
Return Deviation
Treasury Bill 5% 0%
Common Stock 15% 12.85%
• So we observe that the publishing company stock
offers a higher expected return but also entails
more risk as measured by standard deviation. An
investor’s choice of a specific investment will be
determined by their attitude toward risk.
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7-24
25. A Brief History of the Financial
Markets
• We can use the tools that we have
learned to determine the risk-return
tradeoff in the financial markets.
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7-25
26. A Brief History of the Financial
Markets (cont.)
• Investors have historically earned higher
rates of return on riskier investments.
• However, having a higher expected rate of
return simply means that investors
“expect” to realize a higher return. Higher
return is not guaranteed.
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7-26
27. Geometric vs. Arithmetic Average
Rates of Return
• Arithmetic average may not always
capture the true rate of return realized on
an investment. In some cases, geometric
or compound average may be a more
appropriate measure of return.
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7-27
28. Geometric vs. Arithmetic Average
Rates of Return (cont.)
• For example, suppose you bought a stock
for $25. After one year, the stock rises to
$30 and in the second year, it falls to $15.
What was the average return on this
investment?
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7-28
29. Geometric vs. Arithmetic Average
Rates of Return (cont.)
• The stock earned +20% in the first year
and -50% in the second year.
• Simple average = (20%-50%) ÷ 2 = -15%
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7-29
30. Geometric vs. Arithmetic Average
Rates of Return (cont.)
• However, over the 2 years, the $25 stock
lost the equivalent of 22.54%
({($15/$25)1/2} - 1 = 22.54%).
• Here, -15% is the simple arithmetic
average while -22.54% is the geometric or
compound average rate.
• Which one is the correct indicator of
return? It depends on the question being
asked.
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7-30
31. Geometric vs. Arithmetic Average
Rates of Return (cont.)
• The geometric average rate of return
answers the question, “What was the
growth rate of your investment?”
• The arithmetic average rate of return
answers the question, “what was the
average of the yearly rates of return?
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7-31
33. Computing Geometric Average Rate
of Return (cont.)
Compute the arithmetic and geometric
average for the following stock.
Year Annual Rate of Value of the
Return stock
0 $25
1 40% $35
2 -50% $17.50
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7-33
34. Computing Geometric Average Rate
of Return (cont.)
• Arithmetic Average = (40-50) ÷ 2 = -5%
• Geometric Average
= [(1+Ryear1) × (1+Ryear 2)]1/2 - 1
= [(1.4) × (.5)] 1/2 - 1
= -16.33%
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7-34
35. Choosing the Right “Average”
• Both arithmetic average geometric average are important
and correct. The following grid provides some guidance as
to which average is appropriate and when:
Question being Appropriate Average
addressed: Calculation:
What annual rate of The arithmetic average
return can we expect calculated using annual
for next year? rates of return.
What annual rate of The geometric average
return can we expect calculated over a
over a multi-year similar past period.
horizon?
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36. What Determines Stock Prices?
• In short, stock prices tend to go up when
there is good news about future profits,
and they go down when there is bad news
about future profits.
• Since US businesses have generally done
well over the past 80 years, the stock
returns have also been favorable.
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7-36
37. The Efficient Market Hypothesis
• The efficient market hypothesis (EMH) states
that securities prices accurately reflect future
expected cash flows and are based on information
available to investors.
• An efficient market is a market in which all the
available information is fully incorporated into the
prices of the securities and the returns the
investors earn on their investments cannot be
predicted.
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38. The Efficient Market Hypothesis
(cont.)
• We can distinguish among three types of
efficient market, depending on the degree
of efficiency:
1. The Weak-Form Efficient Market Hypothesis
2. The Semi-Strong Form Efficient Market
Hypothesis
3. The Strong Form Efficient Market Hypothesis
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7-38
39. The Efficient Market Hypothesis
(cont.)
(1) The Weak-Form Efficient Market
Hypothesis asserts that all past security
market information is fully reflected in
security prices. This means that all price
and volume information is already
reflected in a security’s price.
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7-39
40. The Efficient Market Hypothesis
(cont.)
(2) The Semi-Strong-Form Efficient
Market Hypothesis asserts that all
publicly available information is fully
reflected in security prices. This is a
stronger statement as it includes all public
information (such as firm’s financial
statements, analysts’ estimates,
announcements about the economy,
industry, or company.)
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7-40
41. The Efficient Market Hypothesis
(cont.)
(3) The Strong-Form Efficient Market
Hypothesis asserts that all information,
regardless of whether this information is
public or private, is fully reflected in
securities prices. It asserts that there isn’t
any information that isn’t already
embedded into the prices of all securities.
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