University at Albany School of Business Fall 2005 Professor Ross Miller Copyright 2005 by Ross M. Miller. All rights reserved Fin 603 Week 8 Common Stock: Returns and Volatility
University at Albany School of Business
Fall 2005 Professor Ross Miller
Copyright 2005 by Ross M. Miller. All rights reserved
Fin 603 Week 8
Common Stock: Returns and Volatility
Professor Ross Miller • Fall 2005 2
Grade Conversion Table (“The Curve”) for the Midterm Exam
Points convert to GPA equivalent number according to the following formula:
GPA equivalent = 4.33 – (90 – Test score)/18
For example,• 84 = 4.00 = A 81 = 3.83 = lowest A• 75 = 3.50 = lowest A- 69 = 3.16 = lowest B+
Mean and median grade were both roughly 75
Professor Ross Miller • Fall 2005 3
Weeks 8 through 11
Week 8: Stocks
Week 9: Portfolio material required for the Google exercise
Week 10: Advanced portfolio material
Week 11: Options
Professor Ross Miller • Fall 2005 4
A Quick Guide to Bodie/Kane/Marcus
Chapter 2• Section 2.3 introduces stock as a financial
instrument• Section 2.4 discusses how stocks index are
constructed
Chapter 3: Stock trading, including short selling
Chapter 4: Mutual funds, including ETFs
Professor Ross Miller • Fall 2005 5
A Quick Guide to Bodie/Kane/Marcus (cont.)
Chapter 5: Stocks are risky and have higher returns than fixed-income securities
Chapter 6: Risk aversion means people require higher returns to hold more volatile assets
Chapter 7: Tracing out the CAL/CML and maximizing utility relative to it
Chapter 8: Portfolios of risky assets
Professor Ross Miller • Fall 2005 6
A Quick Guide to Bodie/Kane/Marcus (cont.)
Chapters 9 and 10: CAPM and implementing a version of it with index models
Chapter 11: Multi-factor models
Chapter 12: Efficient markets
Chapter 13: Problems with everything you are learning in the previous chapters
Chapters 17-19: The cash flow approach to valuing securities
Professor Ross Miller • Fall 2005 7
A Quick Guide to Bodie/Kane/Marcus (cont.)
Chapters 24-27: Useful info for building portfolios• Performance measures (Ch. 24)• International diversification (Ch. 25)• Improving on index performance (Ch. 26 and 27)
Professor Ross Miller • Fall 2005 8
Common Stock
A share in the ownership of a company (equity) and a right to share of its profits
Stock holders have the last claim on the assets of a company (a residual interest)
Ownership of stock has limited liability, you lose at most what you paid for the stock
Common stock includes not only profits, but also voting rights (sometimes limited, as in the case of Google)
Professor Ross Miller • Fall 2005 9
Two Special Kinds of “Stock”
ADRs (or ADSs)• Shares of international companies that trade on
U.S. exchanges • For example, Sony (SNE) & Nokia (NOK).
ETFs (Exchange-Traded Funds)• Shares in portfolios that usually track specific
stock indexes• For example, SPDRs (SPY) & Quads (QQQQ)
Professor Ross Miller • Fall 2005 10
Key Stock Info for Microsoft (from Yahoo!)
Professor Ross Miller • Fall 2005 E=mcE=mc2211
The Concept of Efficiency
Technical economic definition: No way to make anyone better off without making someone else worse off
For an individual: Doing the best you can do with what you have
For portfolios: No way to rearrange things to get more return without taking on more risk
For financial markets: No way to use market data and information to “beat the market”
Professor Ross Miller • Fall 2005 E=mcE=mc2212
Conditions that Promote Efficiency
No single dominant player or cartel of dominant players
Easy substitution of items (limited product differentiation)
Free flow of information
Low barriers to trade• Low commissions• Low taxes• Minimal regulation
Professor Ross Miller • Fall 2005 E=mcE=mc2213
Efficient-Market Hypothesis (EMH) andTechnical Analysis
The efficient-market hypothesis (which comes in three forms) states basically that there is no way to make “excess profits” by looking at any past public information about a company
In particular, this means that “technical analysis” (look at stock graphs, etc.) does not work
It also means that whatever “behavioral anomalies” exist in financial markets are too small and fleeting to exploit profitably
Professor Ross Miller • Fall 2005 E=mcE=mc2214
Consequences of the EMH
Stock prices are efficient aggregators of information about a company
Returns that appear excessive can be interpreted as the return for bearing risk (we will see that only certain risks are rewarded)
The path of a stock’s price may not allow us to predict the future, but they can tell us a lot about the company and its risk
Professor Ross Miller • Fall 2005 E=mcE=mc2215
Consequences of the EMH (continued) Prices are a more reliable source of information
than accounting-based data• Stock prices are extremely rarely falsified or
restated• Stock prices are difficult, but not impossible, to
manipulate• Severely misstated accounting numbers can still
work their way into stock prices (Enron, Worldcom, Refco, etc.)
Professor Ross Miller • Fall 2005 E=mcE=mc2216
Consequences of the EMH (continued) EMH supports investing in index funds rather
than trying to pick individual stocks• Greatly reduces management fees• Provides cheap diversification (we will see that
diversification is a good thing)• Low-turnover indexes generate low capital gains
taxes
Professor Ross Miller • Fall 2005 E=mcE=mc2217
Consequences of the EMH (continued) EMH supports investments that go beyond
traded U.S. stocks• Despite increasing globalization of U.S.
company, adding international companies to a portfolio aids diversification
• Prudent venture capital investments provide opportunities not available in traded stocks with much higher risk
• Real estate can also enter into the mix
Professor Ross Miller • Fall 2005 E=mcE=mc2218
The Two Sources of Returns from Stock
Dividends• Quarterly payments by established companies• Stock yields used to be higher than bond yields• The price of a stock drops by the amount of its
dividend the day it goes “ex-dividend”
Capital Gains• Appreciation in the price of the stock• Not guaranteed• Usually taxed at a lower rate than dividends• Aided by companies buying back their own shares
Professor Ross Miller • Fall 2005 E=mcE=mc2219
Discounted Dividend Model (DDM)
Notice that if one holds a stock indefinitely, dividends are the only cash flow that one receives
Basic Idea: Value(stock) = NPV(future dividends) For a constant discount rate and dividend growth
rate, this is just a growing perpetuity Hence, Value(stock) = Next dividend/(r-g),
where r = stock discount rate, g = dividend growth rate
The main problem is knowing r and g
Professor Ross Miller • Fall 2005 20
Warren Buffett: Sage of Omaha
Chairman of Berkshire Hathaway(BRKa)
Protégé of Benjamin Graham:The father of fundamental analysis
Proponent of “value investing,” skeptical of paying for growth and technology
Professor Ross Miller • Fall 2005 E=mcE=mc2221
Fundamental Stock Valuation
Stocks are valued based on their ability to generate future cash flows
Higher cash flows are good
The most popular measure (but not always the best) measure of the relative cash flow generated by a company is its P/E (Price/Earnings) ratio
Published “Book Values” are rarely used in fundamental analysis
Professor Ross Miller • Fall 2005 E=mcE=mc2222
Fundamental Stock Valuation (continued)
Fundamental valuation methods are not limited to the discounted dividend model
Free cash flows can also be discounted• This makes the most sense for a company that
is an acquisitions target• Valuation is still very dependent on growth rates• This article, which later paints a grim picture of
the prospects for the stock market, presents an argument that Google is vastly overpriced based on expected future cash flows
Professor Ross Miller • Fall 2005 E=mcE=mc2223
Size Matters
A standard measure of a stock’s “size” is the dollar value of its shares, known as market capitalization
Large companies are different from small companies
• Usually less volatile• Usually more closely linked to overall market
conditions, if only because they constitute a larger share of “the market”
Professor Ross Miller • Fall 2005 E=mcE=mc2224
The Style Matrix
Professor Ross Miller • Fall 2005 E=mcE=mc2225
Holding-Period Return (HPR)
PriceBeginningDividendPriceBeginningPriceEnding
ReturnPeriodHolding
Professor Ross Miller • Fall 2005 E=mcE=mc2226
Getting Data Historical stock data is available on Yahoo!
Finance (here is Google)
Reuters Investor has some good additional data
GoogleStats.xls has weekly HPRs for fed funds (a proxy for the “risk-free” rate of return) and the seven stocks involved in the Google exercise
Notice that your professor has used a clever trick to deal with dividend payments; however, this trick does not deal with stock splits
Professor Ross Miller • Fall 2005 E=mcE=mc2227
Holding-Period Return Example:MSFT between August 10 and 17, 2005
Closing price on August 10: $27.05
August 15 dividend: $0.08
Closing price on August 17: $26.72
HPR = ($26.72 – $27.05 + $0.08)/$27.05 = –$0.25/$27.05 = –.00924 = –0.924%
Professor Ross Miller • Fall 2005 E=mcE=mc2228
Annualizing HPRs
With few exceptions, everything to do with stock returns is reported as an annualized figure
Weekly returns are annualized by compounding them up 52 times (we usually ignore the extra day or two), so:
Annual return = (1+Weekly Return)52 – 1
In the previous example, Annual return =(1 – 0.00924) 52 – 1 = – 38.28%
Professor Ross Miller • Fall 2005 E=mcE=mc2229
More On HPR
A single week’s HPR can be misleading• HPRs can change a lot from week to week
More useful info is the mean and standard deviation of the weekly return (daily and monthly returns can also be used, depending on the purpose) over many (at least 30) observations
Finally, one may want to consider only the excess return relative to a benchmark rate; usually, “cash” or an indexed investment
Professor Ross Miller • Fall 2005 E=mcE=mc2230
The Standard Deviation of Returns
This is also known as the stock’s volatility; however, there are other methods of measuring volatility
Volatility is a standard measure of the stock’s risk—higher volatility means more risk
Annualizing volatility is somewhat tricky:
yearperPeriodsVolatilityPeriodicVolatilityAnnual
For weekly returns, we multiply by 52 to annualize
Professor Ross Miller • Fall 2005 E=mcE=mc2231
Some Numbers from the Last 60 Weeks
Fed Funds GOOG SPY QQQQ YHOOMean Return 2.654% 158.736% 8.957% 12.044% 18.548%Std Dev Return 0.094% 41.073% 9.852% 13.224% 25.991%Mean Excess Return 0 152.163% 6.143% 9.152% 15.491%Sharpe Ratio 3.704696 0.623579 0.692107 0.596035
Professor Ross Miller • Fall 2005 E=mcE=mc2232
Volatility and Risk Aversion
Chapter 6 of BKM is about quantifying risk aversion
The standard method is to create a utility function that rewards higher returns and punishes higher risk
The utility function that BKM favor is:
2005.)( ArEU
Professor Ross Miller • Fall 2005 E=mcE=mc2233
Some Comments about BKM Chapter 6
BKM use “scenarios” to illustrate “risky” situations
• Scenarios can be useful and are frequently used by financial planners, rating agencies, etc.
• Scenarios do not naturally present themselves in the real world
In recent years, a value of A much greater than BKM would suggest is required to get reasonable results
Professor Ross Miller • Fall 2005 E=mcE=mc2234
The Normal Distribution
Knowing a mean and a standard deviation is all you need to plot a normal distribution
It is often convenient to assume that HPRs for stocks are normally distributed
In reality, they are not, but sometimes this assumption is not too dangerous
Professor Ross Miller • Fall 2005 E=mcE=mc2235
What Does the Past Have to Do with the Future?
Not as much as we would like it to have
Historical rates of returns are not the best estimates of future returns
Historical volatilities are more accurate, but for many stocks there is an even better number—implied volatility, which is computed from option prices
Professor Ross Miller • Fall 2005 E=mcE=mc2236
Looking up the Implied Volatility
Visit ivolatility.com and enter stock symbol for “Basic Options”
• Here is Google• Here is Microsoft
A good estimate of annual volatility is the average of the IV Index Call” and “IV Index Put” for a stock (the value of options depends mainly on a stock’s volatility)
Professor Ross Miller • Fall 2005 37
The Most Popular Measure of Volatility:VIX (^VIX)
VIX stands for “volatility index”
It is the implied volatility of the S&P 500, computed a collection of prices on S&P 500 options
Both futures and options on VIX are traded on the CBOE
Variants have appeared (VXN and VXD)
Professor Ross Miller • Fall 2005 38
For Next Time
Read Chapters 5-10 of BKM
Think about what possible use the data in GoogleStats.xls could be for the Google exercise
Specifically, use GoogleStats.xls to compute useful statistics for portfolios created from Google and the six other stocks if you had held them in the past