Слайд 1Class
Risk and Return
Historical returns in the USA.
Sigma. CV. Security Characteristic
Line (SCL). Beta. Security Market Line (SML). CAPM formula.
Study materials:
KR: Ch. 11, 12.
RWJ: Ch. 9, 10
BM: Ch. 7, 8
Слайд 2Value of $1 invested in 1926
Слайд 3Risk and Return
Risk - The chance that an investment's actual
return will be different than expected. This includes the possibility of losing some
or all of the original investment. Total risk measured by the standard deviation of the historical returns.
A fundamental idea in finance is the relationship between risk and return. The greater the amount of risk that an investor is willing to take on, the greater the potential return. The reason for this is that investors need to be compensated for taking on additional risk.
E.g., a U.S. Treasury bonds (bills) is considered
to be the safest investment and, when compared
to a corporate bond, provides a lower return.
The reason is that a corporation is much more
likely to go bankrupt than the U.S. government.
Слайд 5Risk and Return
P1 – P0 (+ ∑D)
HPR, % =
P0
Return, % = P1 / P0 - 1
CV
= sigma / mean return
Слайд 6
Measuring Returns
Historical returns:
X1=10%, X2= (-5%), X3 = 20%
Arithmetic Average:
[0.10
+ (-0.05) + 0.20] / 3 = 8.33% - usual
way
Geometric Average:
[(1.10)*(0.95)*(1.20)]1/3 - 1 = 7.84% - more correct
Слайд 7Общий риск: стандартное отклонение
Слайд 82. Risk and return relationship
Общий риск: стандартное отклонение
Слайд 9Return (actual), mean return, %
CAPM-return (model return), %
Risk-free return, %
Excess
return, %
Abnormal return, %
Total risk (sigma), %
Systematic risk (beta), t
Unsystematic
risk, %
Coefficient of correlation, t
Coefficient of determination, t
Coefficient of variation (CV), t
Sharpe’s measure (S), t
Treynor’s measure (T), t
Appraisal ratio (AR), t
Z-beta, t
Z-alpha, %
Degree of volatility, t
Risk and Return measures
Слайд 10
Measuring Risk: ERR
Expected return:
The return for an asset is
the probability weighted average return in all scenarios.
Слайд 11 Variance: A measure of the dispersion of a set of
data points around their mean value.
Variance measures the variability
(volatility) from an average. Volatility is a measure of risk, so this statistic can help determine the risk an investor might take on when purchasing a specific security.
The variance of an asset’s expected return is the expected value of the squared deviations from the expected returns.
Measuring Risk: ERR
Слайд 12
Standard deviation:
Square root of Variance. A measure of the
dispersion of a set of data from its mean. The
more spread apart the data, the higher the deviation.
In finance, it is a measure of total risk of a financial asset.
Measuring Risk: ERR
Слайд 13
Measuring Risk: ERR
Example: Calculating ERR, Variance, and Standard deviation
Слайд 14
Measuring Risk: Historical RR
Variance:
The variance of an asset’s historical
returns is the sum of the squared deviations divided by
(n-1).
Standard deviation:
Square root of variance.
Слайд 15
Measuring Risk: Historical RR
Example: Calculating Mean, Variance, and
Standard deviation
Слайд 16
Risk and Return Relationship
Coefficient of Variation (CV) =
Standard deviation
/ Expected (historical) rate of return.
Measures risk-return relationship, i.e.,
sigma per 1 %
of return.
better choice
Слайд 17Risk and Return characteristics, World, 2009
Слайд 181
2
3
4
Return, %
Sigma, %
• 2 vs. 1; return is higher
• 2
vs. 3; risk is lower
• 4 vs. 3; return is
higher
Types of investors: Risk-averse, (Risk-neutral), Risk-seeker.
A rational investor would choose the securities that locate in the left upper corner. CV MIN.
R&RR and types of investors
Слайд 22
Beta
Beta: A measure of systematic risk, of a security (or a
portfolio) in comparison to the market (market index, proxy). Measure
of elasticity.
Equals the variable coefficient “b” in the linear regression equation:
Y = a + b*X + ε
Graphically, Beta = Y / X
A beta of greater than 1 indicates that the security's price is more volatile than the market, more risky. “Aggressive” security.
The Security characteristic line is more steep.
A beta of less than 1 indicates that the security's price is less volatile than the market, less risky. “Defensive” security.
Слайд 23
Total Risk: Components
Systematic Risk - The risk inherent to the
entire market, or market
segment. Also known as “non-diversifiable risk"
or "market risk."
E.g., interest rates, recession and wars represent sources of systematic risk because they affect the entire market and cannot be avoided through diversification. Affects a broad range of securities. Even a portfolio of well-diversified assets cannot escape all risk.
Measured with BETA.
Unsystematic Risk – Company-specific risk that is inherent in each
investment. Can be reduced through appropriate diversification (=strategy
designed to reduce risk by spreading the portfolio across many
investments.
Also known as "specific risk", "diversifiable risk“, or "residual risk".
E.g., a sudden strike by the employees of a company is considered
to be unsystematic risk.
Слайд 27Correlations of indices with S&P500
2010 2009
North America: 0,80 – 0,95 0,88
– 0,99
South America: 0,70 – 0,76 0,83 – 0,88
Western Europe: 0,80 –
0,87 0,79 – 0,92
Australia and NZ: 0,76 – 0,80 0,47 – 0,65
Russia: 0,71 – 0,76 0,53 – 0,59
Asia: 0,45 – 0,77 0,27 – 0,76
Ukraine: 0,46 – 0,51 0,44 – 0,48
Слайд 29
Security Market Line (SML)
Return,%
.
rf
Risk-free rate
Market Portfolio
Beta
1.0
SML
SML equation
= rf + ( rm - rf ) =
CAPM
Слайд 30rm = 13%, rf = 3%
x = 1.20, then:
E(rx) = 3%
+ 1.2*(13%-3%) = 15%
y = 0.80, then:
E(ry) = 3% +
0.8*(13%-3%) = 11%
Sample Calculations for SML
Слайд 31Alpha
Alpha (abnormal return; excess return) = ract - rf
rp =
rf + p ( rm - rf ) (+/- alpha)
Слайд 36Stock BEHAVIOUR – from the SCL equation
Find and describe:
Beta
Alpha
Correlation
coef.
Sigma
Mean return
CV
Слайд 37Class
Risk and Return
Additional materials (Advanced level)
Слайд 38Capital Allocation Line (CAL)
A line created in a graph of
all possible combinations of risky and risk-free assets.
The graph displays
to investors the return they can make by taking on a certain
level of risk. Also known as the "reward-to-variability ratio".
E(r)
E(rp) = 15%
rf = 7%
p = 22%
0
P
F
E(rp) -
rf = 8%
CAL
Слайд 39
Portfolio risk and return: Return
The rate of return on a
portfolio is a weighted average of the rates of return
of each asset comprising the portfolio, with the portfolio proportions ($) as weights.
rp = w1r1 + w2r2
w1 = Proportion of funds in Security 1, %
w2 = Proportion of funds in Security 2, %
r1 = Expected return on Security 1, %
r2 = Expected return on Security 2, %
Слайд 40
Portfolio risk and return: Covariance
Covariance is a measure of the
linear association between the 2 variables. A measure of the
degree to which returns on two risky assets move
in tandem. A positive covariance means that asset returns
move together. A negative covariance means that returns move inversely.
Covariance between Stock 1 and Stock 2 =
OR:
Слайд 41
Portfolio risk and return: Covariance
Covariance between Stock 1 and Stock
2 =
= Cov 1,2 = ρ1,2 σ 1 σ
2
Слайд 42
Portfolio risk and return: Correlation
Correlation is a measure of the
linear association between
the 2 variables. In the world of
finance, a statistical measure of
how two securities move in relation to each other.
ρ 1,2 = Cov 1,2 / σ 1 σ 2
Correlation coefficient is ALWAYS [-1; 1].
Perfect positive correlation (a correlation coefficient of +1) implies that as one security moves, either up or down, the other security will move in lockstep, in the same direction. Alternatively, perfect negative correlation means that if one security moves in either direction the security that is perfectly negatively correlated will move by an equal amount in the opposite direction. If the correlation is 0, the movements of the securities are said to have no correlation; they are completely random.
Слайд 43
Portfolio risk and return: Sigma
When two risky assets with variances
12 and 22, respectively, are combined into a
portfolio with portfolio weights w1 and w2, respectively, the portfolio variance is given by:
p2 = w1212 + w2222 + 2w1w2 Cov(r1r2) =
= w1212 + w2222 + 2w1w2 ρ 1 2
Hence, the portfolio’s standard deviation - p - is the square root of the above formula.
Слайд 44
Portfolio risk and return: Sigma
Rule: When a risky asset is
combined with a risk-free asset, the portfolio standard deviation equals
the risky asset’s standard deviation multiplied by the portfolio proportion invested in the risky asset.
Слайд 45
DIVERSIFICATION
Coca Cola
Reebok
Standard Deviation
35% in Reebok, 65% in Coca-Cola
Expected Returns and Standard Deviations vary given different weighted combinations
of the stocks
Expected Return, %
See: file “port.xls”
Слайд 46Efficient Frontier
Example
Correlation Coefficient = 0.4
Stocks s % of Portfolio Avg
Return
ABC Corp 28 60% 15%
Big Corp 42 40% 21%
Standard Deviation = weighted avg = 33.6
Standard Deviation = Portfolio = 28.1
Return = weighted avg = Portfolio = 17.4%
Слайд 47Efficient Frontier
Example
Correlation Coefficient = 0.4
Stocks s % of Portfolio Avg
Return
ABC Corp 28 60% 15%
Big Corp 42 40% 21%
Standard Deviation = weighted avg = 33.6
Standard Deviation = Portfolio = 28.1
Return = weighted avg = Portfolio = 17.4%
Let’s Add stock New Corp to the portfolio
Слайд 48Efficient Frontier
Example
Correlation Coefficient = 0.3
Stocks s % of Portfolio Avg
Return
Portfolio 28.1 50% 17.4%
New Corp 30 50% 19%
NEW Standard Deviation = weighted avg = 31.80
NEW Standard Deviation = Portfolio = 23.43
NEW Return = weighted avg = Portfolio = 18.20%
Слайд 49Efficient Frontier
Example
Correlation Coefficient = 0.3
Stocks s % of Portfolio Avg
Return
Portfolio 28.1 50% 17.4%
New Corp 30 50% 19%
NEW Standard Deviation = weighted avg = 31.80
NEW Standard Deviation = Portfolio = 23.43
NEW Return = weighted avg = Portfolio = 18.20%
NOTE: Higher return & Lower risk
How did we do that? DIVERSIFICATION
Слайд 50
Diversification of Unsystematic Risk
Слайд 53ОНД, %
Стандартное отклонение, %
Stock B
Stock A
Corr = +1
Corr = -1
Corr
= 0
Portfolio diversification: 2 stocks
Слайд 54
Efficient Frontier
Standard Deviation
Each half egg shell represents the possible weighted
combinations for two stocks.
The composite of all stock sets constitutes
the efficient frontier
Expected Return, %
Слайд 55
Efficient Frontier
A
B
N
AB
ABN
Goal is to move up and left
Sigma
Return, %
Слайд 56
Efficient Frontier
Return, %
Low Risk
High Return
High Risk
High Return
Low Risk
Low Return
High Risk
Low
Return
Sigma
Goal is to move up and left
Слайд 57
Efficient (Markowitz) frontier
A line created from the risk-reward graph, comprised
of optimal portfolios.
Слайд 58
Political Risks: Mechel Story
“В четверг (25 июля) премьер-министр Владимир Путин
встретился в Нижнем Новгороде с представителями крупнейших российских металлургических
и угольных компаний и высказался о ситуации на российском рынке стали.
Премьер-министр неожиданно сделал ряд жестких заявлений в отношении Мечела (ОАО «ЧМЗ»). По сути, он обвинил компанию в нерыночном поведении и предположил, что прокуратуре следуетобратить внимание на торговую деятельность компании.
Этих заявлений оказалось достаточно, чтобы обрушить котировки Мечела – с четверга они упали на 37,6%, заставив инвесторов гадать о будущем компании – ведущего производителя коксующегося угля в России.”
«Тройка-Диалог», 25 июля 2008 г. (www.troika.ru)
Слайд 60
Political Risks: MICEX Index, 2008
Inauguration of president
Medvedev
Putin accuses
“Mechel” of
fishy business
Russian
intrusion into
Georgia
Putin’s speech in Sochi,
VII Economics Forum
Medvedev:
to establish a missile complex in Kaliningrad
Слайд 61
Portfolio risk and return: Beta
Systematic Risk - The risk inherent
to the entire market, or market
segment. Also known as
"un-diversifiable risk" or "market risk."
E.g., interest rates, recession and wars represent sources of systematic
risk because they affect the entire market and cannot be avoided through
diversification. Affects a broad range of securities. Even a portfolio of well-
diversified assets cannot escape all risk.
Measured with BETA.
Still, one can diversify the systematic risk – in the sense that
one can choose securities with different betas (defensive vs. aggressive stocks) and combine them.
Слайд 62
Portfolio risk and return: Beta
The Beta of a portfolio is
the weighted average of the rates of return of each
asset comprising the portfolio, with the portfolio proportions ($) as weights.
bp = w1 b1 + w2 b2
w1 = Proportion of funds in Security 1, %
w2 = Proportion of funds in Security 2, %
b1 = Beta of Security 1
b2 = Beta of Security 2