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2023 Risk and Return

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RISK AND RETURN

TCH 302

Cecchetti, Chapter 5

1
Introduction
• Everyday decisions involve financial and
economic risk.

• How much car insurance should I buy? Should


I refinance my mortgage now or later?

• Need to quantify(measure) risk to calculate a


fair price for financial instruments and
transferring risk.

2
Defining Risk
• Dictionary definition, risk is “the possibility of
loss or injury.”

• For outcomes of financial and economic


decisions, we need a different definition:

“ Risk is a measure of uncertainty about the


future payoff to an investment, assessed over
some time horizon and relative to a
benchmark”.
3
Measuring Risk

• In determining expected return, we need


to understand expected value investment
return out of all possible values.

4
Possibilities, Probabilities, and
Expected Value
• Probability theory states that considering
uncertainty requires:

• Listing all the possible outcomes.

• Figuring out the chance of each one occurring.


Probability is a measure of the likelihood that
an event will occur.

• It is always between zero and one. Can also be


stated as frequencies 5
Example 1
• Assume we have an investment that can rise or fall in
value.

• $1,000 stock investment that has a 50% probability to


increase to $1,400 or 50% probability to fall to $700.

• The amount you could get back is the investment’s


payoff.

• We can construct a table and determine the


investment’s expected value - the average or most
likely outcome.
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Possibilities, Probabilities,
and Expected Value

7
Example 2
• What if the $1,000 Investment could:

• Rise in value to $2,000, with probability of 0.1

• Rise in value to $1,400, with probability of 0.4

• Fall in value to $700, with probability of 0.4

• Fall in value to $100, with probability of 0.1

Lecture 1 8
Variance and Standard Deviation

• Case 2 is more spread out - higher


standard deviation - therefore it carries
more risk.

9
Measures of Risk
• The wider the range of outcomes, the greater the risk.
Measuring the spread allows us to measure the risk -
variance and standard deviation.

• A risk free asset is an investment whose future value is


knows with certainty and whose return is the risk free
rate of return.

• The payoff you receive is guaranteed and cannot vary.

10
Variance and Standard Deviation
• Variance is the average of the squared deviations of
the possible outcomes from their expected value,
weighted by their probabilities.

• Compute expected value.

• Subtract expected value from each of the possible


payoffs and square the result. Multiply each result
times the probability. Add up the results.

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Variance and Standard Deviation
• 1. Compute the expected value: ($1400 x ½) + ($700 x ½) =
$1,050.

• 2. Subtract this from each of the possible payoffs and


square the results: $1,400 – $1,050 = ($350)2 =
122,500(dollars)2 and $700 – $1,050 = (–$350)2
=122,500(dollars)2

• 3. Multiply each result times its probability and add up the


results: ½ [122,500(dollars)2] + ½ [122,500(dollars)2]
=122,500(dollars)2

• 4. The Standard deviation is the square root of the variance:


12
Variance and Standard Deviation

• The greater the standard deviation, the


higher the risk.

• Case 1 has a standard deviation of $350


Case 2 has a standard deviation of $528
Case 1 has lower risk.

13
Leverage and Risk and Return
• Leverage is the practice of borrowing (using debt) to
finance part of an investment.

• Financial Intermediaries always do this.

• Leverage increases expected return and it also


increases the standard deviation of the returns –
increases risk.

• Leverage magnifies the effect of price changes and


adds to risks in the financial system.

14
Value at Risk
• Sometimes we are less concerned with spread than
with the worst possible outcome

• Example: We don’t want a bank to fail Value at Risk


(VaR):

• The worst possible loss over a specific horizon at a


given probability.

• What is the VaR for Case 2?, Case 1?

15
Value at Risk

• VaR answers the question: how much will


I lose if the worst possible scenario
occurs? Sometimes this is the most
important question.

16
Idiosyncratic and Systematic Risk

• All risks can be classified into two


groups:

• Those affecting a small number of people


or firms but no one else: idiosyncratic or
unique risks.

• Those affecting everyone: systematic or


economy-wide risks.
17
Systemic risks vs specific risks

• Systemic risks are threats to the system


as a whole, not to a specific firm or
market.

18
Risk Aversion, the Risk
Premium, and the Risk-Return
Tradeoff
• Most people do not like risk and will pay to avoid it, most of us are
risk averse. Insurance is a good example of this.

• A risk averse investor - will always prefer an investment with a


certain return to one with the same expected return but any amount
of uncertainty. Therefore, the riskier an investment, the higher the
risk premium.

• The compensation investors required to hold the risky asset.

19
Hedging Risk
• Results of Possible Investment

• Strategies: Hedging Risk

• Initial Investment = $100

20
Reducing Risk through
Diversification
• Idiosyncratic risk can be reduced through
diversification, the principle of holding
more than one risk at a time.

21
Spreading Risk

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Excercise
• Assume that the economy can experience high growth, normal
growth, or recession. Under these conditions, you expect the
following stock market returns for the coming year:
State of the Economy Probability Return

High Growth 0.2 +30%

Normal Growth 0.7 +12%

Recession 0.1 -15%

• Compute the expected value of a $1,000 investment over the


coming year. If you invest $1,000 today, how much money do you
expect to have next year? What is the percentage expected rate of
return?

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