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The stock market is
no different from any other market. The laws of supply and demand ultimately
determine the price of the merchandise. If there are more buyers than
sellers for a particular stock, the price of that stock will rise. If there
are more sellers than buyers, the stock price will fall.
The conventional
market wisdom for many years was that the stock market, as a result of the
interplay between these vast numbers of buyers and sellers, was truly
efficient. Proponents of the efficient market theory believe that
since all market participants have access to the same information about a
stock, the price of a stock should reflect the knowledge and expectations of
all investors. Thus, an investor should not be able to beat the market since
there is no way for him or her to know something about a stock that isnt
already reflected in the stocks price. For that reason, stock prices move
in a random fashion as new information comes into the market and is quickly
reflected in the stock price.
Now, I do believe
that markets are efficient, to a point. However, market efficiency assumes
all market participants behave in a rational fashion all of the time.
Unfortunately, the human condition (and, remember, humans ultimately decide
stock prices) does not lend itself to full-time rational thinking.
That humans behave
irrationally when it comes to things financial has gained momentum in the
academic world in recent years. In fact, the Nobel Prize in Economic
Sciences in 2002 went to Daniel Kahneman, who isnt even an economist.
Kahneman is a psychologist who still teaches Psychology 101 at Princeton.
Kahneman, along with his long-time collaborator Amos Tversky (who passed
away in 1996) published a paper in 1979, Prospect Theory: An Analysis of
Decision Under Risk. That paper formed the basis for the concept of
loss aversion; that is, people generally derive more pain from a loss
than they do pleasure from a gain.
Kahneman and
Tversky also found that individuals tend to overweight recent data in making
forecasts and judgments. Think about how most decisions are made. All of us
have a tendency to focus on recent information, to extrapolate the near term
into the long term. This tendency helps to explain the herd mentality on
Wall Street people buy winning stocks because they expect near-term
winners to be long-term winners. Or, people sell stocks everyone else is
selling simply because recent data (i.e., the stock is falling in price)
influences their decisions.
A student of
Kahneman, University of Chicago professor Richard Thaler, has been one of
the leaders in applying behavioral psychology to the world of economics and
finance. For example, Thaler has used behavioral psychology to research
contrarian investing. Contrarian investors buy investments that are
out of favor with the general investing public. Contrarians believe that if
the essence of successful investing is buying stocks at cheap prices, then
stocks that are being shunned by investors should represent the stocks
offering the best value.
Contrarian
investment strategies are successful because they take advantage of investor
overreaction. This overreaction, so say behavioral psychologists, is partly
a result of investors making bad projections about stock prices as a result
of overweighting recent events. Of course, buying a stock that has fallen
sharply wont make you any money if it stays down forever. Thats where
the second important piece of the puzzle comes into play. Contrarian
investors also depend on the concept of mean reversion.
Think for a moment
about the world around you. Things weather patterns, peoples
emotions, even societal behavior tend to track some equilibrium range, a
steady state, if you will. Occasionally, this steady state gets disrupted.
In the case of weather, you have tornados and hurricanes and floods. In the
case of societal behavior, riots and looting. In the case of human emotions,
the peaks and valleys caused by big events (marriage, children, death).
Thus, in the short run, things have the ability to run to extremes. Over
time, however, things tend to revert to the equilibrium state, the long-run
average. Things cant help but revert to the average, the mean, over time.
Indeed, it requires too much energy for things to stay at the extremes. As
the energy that created the extremes (think wind for hurricanes) dissipates,
things tend to revert to their steady state.
A good analogy for
mean reversion is a rubber band. A rubber band can stretch and contort when
pressure is applied. Once the pressure ceases, however, the rubber band
returns to its steady state. Mean reversion has important implications for
investing, especially contrarian investing. Contrarians believe that if you
buy stocks that have run to extremes on the downside (or sell stocks that
have run to extremes on the upside), you will eventually be rewarded when
mean reversion returns the stocks to their long-run equilibrium price
level.
To be sure, mean
reversion/ contrarian investing is not as simple as going out and buying any
beaten-down stock. For example, the last thing a contrarian wants to do is
buy a cheap stock that gets cheaper and cheaper and cheaper and then becomes
extinct. Bankruptcy is the bane of any contrarian investing strategy.
Bankruptcy steals the time a stock needs to revert to its mean. For that
reason, stocks that seem best situated for a mean-reversion strategy are
large, seasoned, time-tested companies with sound finances and the ability
to weather down cycles in the economy and stock market. When these stocks
show extreme price declines, especially relative to some appropriate
benchmark, smart investors buy.
How do my
worst-to-first investment strategies fit into this more contemporary view of
the investment world? Rather well. My worst-to-first strategies focus
exclusively on buying beaten-up, blue-chip issues in the Dow. These are the
type of companies that have demonstrated over many decades the sort of
financial firepower and staying power that make them well suited for a
mean-reversion investment strategy.
Another reason my
worst-to-first strategies make sense in todays investment environment is
that the strategies investment methodology relies solely on one data
point a stocks 12-month percentage price change. This data point
cannot be fudged, obfuscated, or manipulated. A stocks price change is an
absolute. The same cant be said for revenue, net income, debt, or any
other investment metric found on the balance sheet or income statement. As
weve seen in recent years, corporate America is not above employing fuzzy
accounting or even downright fraud to distort or puff these numbers.
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