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Subject: Technical Analysis - Basics
Last-Revised: 27 Jan 1998
Contributed-By:
Maurice Suhre, Neil Johnson
The following material introduces technical analysis and is intended to
be educational. If you are intrigued, do your own reading. The answers
are brief and cannot possibly do justice to the topics. The references
provide a substantial amount of information.
First, the references; the links point to Amazon, where you can buy
the books if you're really interested.
- John J. Murphy
Technical Analysis of the Futures Markets
- Martin J. Pring
Technical Analysis Explained
- Stan Weinstein
Stan Weinstein's Secrets for Profiting in Bull and Bear Markets
Now we'll introduce technical analysis and explain some commonly
mentioned aspects.
- What is technical analysis?
Technical analysis attempts to use past stock price and volume
information to predict future price movements. Note the emphasis.
It also attempts to time the markets.
- Does it have any chance of working, or is it just like reading
tea leaves?
There are a couple of plausibility arguments. One is that the chart
patterns represent the past behavior of the pool of investors. Since
that pool doesn't change rapidly, one might expect to see similar chart
patterns in the future. Another argument is that the chart patterns
display the action inherent in an auction market. Since not everyone
reacts to information instantly, the chart can provide some predictive
value. A third argument is that the chart patterns appear over and over
again. Even if I don't know why they happen, I shouldn't trade or invest
against them. A fourth argument is that investors swing from overly
optimistic to excessively pessimistic and back again. Technical analysis
can provide some estimates of this situation.
A contrary view is that it is just coincidence and there is little, if
any, causality present. Or that even if there is some sort of causality
process going on, it isn't strong enough to trade off of.
A very contrary view: The past and future performance of a stock may
be correlated, but that does not mean or imply causality. So, relying
on technical analysis to buy/sell a stock is like relying on the position
of the stars in the atmosphere or the phases of the moon to decide whether
to buy or sell.
- I am a fundamentalist. Should I know anything about technical
analysis?
Perhaps. You should consider delaying purchase of stocks whose chart
patterns look bad, no matter how good the fundamentals. The market is
telling you something is still awry. Another argument is that the
technicians won't be buying and they will not be helping the stock move
up. On the other hand (as the economists say), it makes it easy for
you to buy in front of them. And, of course, you can ignore technical
analysis viewpoints and rely solely on fundamentals.
- What are moving averages?
Observe that a period can be a day, a week, a month, or as little as 1
minute. Stock and mutual fund charts normally are daily postings or
weekly postings. An N period (simple) moving average is computed by
summing the last N data points and dividing by N. Moving averages are
normally simple unless otherwise specified.
An exponential moving average is computed slightly differently. Let
X[i] be a series of data points. Then the Exponential Moving Average
(EMA) is computed by:
EMA[i] = (1 - sm) * EMA[i-1] + sm * X[i]
where sm = 2/(N+1), and EMA[1] = X[1].
"sm" is the smoothing constant for an N period EMA. Note that the EMA
provides more weighting to the recent data, less weighting to the old data.
- What is Stage Analysis?
Stan Weinstein [ref 3] developed a theory (based on his observations)
that stocks usually go through four stages in order. Stage 1 is a time
period where the stock fluctuates in a relatively narrow range. Little
or nothing seems to be happening and the stock price will wander back
and forth across the 200 day moving average. This period is generally
called "base building". Stage 2 is an advancing stage characterized by
the stock rising above the 200 and 50 day moving averages. The stock
may drop below the 50 day average and still be considered in Stage 2.
Fundamentally, Stage 2 is triggered by a perception of improved conditions
with the company. Stage 3 is a "peaking out" of the stock price action.
Typically the price will begin to cross the 200 day moving average, and
the average may begin to round over on the chart. This is the time to
take profits. Finally, the Stage 4 decline begins. The stock price drops
below the 50 and 200 day moving averages, and continues down until a new
Stage 1 begins. Take the pledge right now: hold up your right hand and
say "I will never purchase a stock in Stage 4". One could have avoided
the late 92-93 debacle in IBM by standing aside as it worked its way
through a Stage 4 decline.
- What is a whipsaw?
This is where you purchase based on a moving average crossing (or some
other signal) and then the price moves in the other direction giving a
sell signal shortly thereafter, frequently with a loss. Whipsaws can
substantially increase your commissions for stocks and excessive mutual
fund switching may be prohibited by the fund manager.
- Why a 200 day moving average as opposed to 190 or 210?
Moving averages are chosen as a compromise between being too late to
catch much move after a change in trend, and getting whipsawed. The
shorter the moving average, the more fluctuations it has. There are
considerations regarding cyclic stock patterns and which of those are
filtered out by the moving average filter. A discussion of filters is
far beyond the scope of this FAQ. See Hurst's book on stock
transactions for some discussion.
- Explain support and resistance levels, and how to use them.
Suppose a stock drops to a price, say 35, and rebounds. And that this
happens a few more times. Then 35 is considered a "support" level.
The concept is that there are buyers waiting to buy at that price.
Imagine someone who had planned to purchase and his broker talked him
out of it. After seeing the price rise, he swears he's not going to
let the stock get away from him again. Similarly, an advance to a
price, say 45, which is repeatedly followed by a pullback to lower
prices because a "resistance" level. The notion is that there are
buyers who purchased at 45 and have watched a deterioration into a loss
position. They are now waiting to get out even. Or there are sellers
who consider 45 overvalued and want to take their profits.
One strategy is to attempt to purchase near support and take profits near
resistance. Another is to wait for an "upside breakout" where the stock
penetrates a previous resistance level. Purchase on anticipation of a
further move up. [See references for more details.]
The support level (and subsequent support levels after rises) can provide
information for use in setting stops. See the "About Stocks" section of
the FAQ for more details.
- What would cause these levels to be penetrated?
Abrupt changes in a company's prospects will be reacted to in the stock
market almost immediately. If the news is extreme enough, the reaction
will appear as a jump or gap in prices. More modest changes will
result, in general, in more modest changes in price.
- What is an "upside breakout"?
If a stock has traded in a narrow range for some time (i.e. built a
base) and then advances above the resistance level, this is said to be an
"upside breakout". Breakouts are suspect if they do not occur on high
volume (compared to average daily volume). Some traders use a "buy stop"
which calls for purchase when a stock rises above a certain price.
- Is there a "downside breakout"?
Not by that name -- the opposite of upside breakout is called
"penetration of support" or "breakdown". Corresponding to "buy stops,"
a trader can set a "sell stop" to exit a position on breakdown.
- Explain breadth measurements and how to use them.
A breadth measurement is something taken across a market. For example,
looking at the number of advancing stocks compared to declining stocks
on the NYSE is a breadth measurement. Or looking at the number of stocks
above their 200 day moving average. Or looking at the percentage of stocks
in Stage 1 and 2 configurations. In general, a technically healthy market
should see a lot of stocks advancing, not just the Dow 30. If the breadth
measurements are poor in an advancing sense and the market has been
advancing for some time, then this can indicate a market turning point
(assuming that the advancing breadth is declining) and you should consider
taking profits, not entering new long positions, and/or tightening stops.
(See the divergence discussion.)
- What is a divergence? What is the significance?
In general, a divergence is said to occur when two readings are not
moving generally together when they would be expected to. For example,
if the DJIA moves up a lot but the S&P 500 moves very little or even
declines, a divergence is created. Divergences can signify turning
points in the market. At a major market low, the "blue chip" stocks
tend to move up first as investors becoming willing to purchase quality.
Hence the S&P 500 may be advancing while the NYSE composite is moving
very little. Divergences, like everything else, are not 100 per cent
reliable. But they do provide yellow or red alerts. And the bigger the
divergence, the stronger the signal. Divergence and breadth are related
concepts. (See the breadth discussion.)
- How much are charting services and what ones are available?
Commercial services aren't cheap. Daily Graphs (weekly charts with
daily prices) is $465 for the NYSE edition, $432 for the AMEX/OTC
edition. Somewhat cheaper for biweekly or monthly. Mansfield charts
are weekly with weekly prices. Mansfield shows about 2.5 years of
action, Daily Graphs shows 1 year or 6 months for the less active
stocks. Of course there are many charts on the web. See the article
elsewhere in the technical analysis section of this FAQ about free
charts.
S&P Trendline Chart Guide is about $145 per year. It provides
over 4,000 charts. These charts show one year of weekly price/volume
data and do not provide nearly the detail that Daily Graphs do. You
get what you pay for. There are other charting services available.
These are merely representative examples.
- Can I get charts with a PC program?
Yes. There are many programs available for various prices. Daily quotes
run about $35 or so a month from Dial Data, for example. Or you can
manually enter the data from the newspaper.
- What would a PC program do that a charting service doesn't?
Programs provide a wide range of technical analysis computations in
addition to moving averages. RSI, MACD, Stochastics, etc., are routinely
included. See Murphy's book [Ref 1] for definitions. Frequently you can
change the length of the moving averages or other parameters. As another
example, AIQ StockExpert provides an "expert rating" suggesting purchase
or short depending on the rating. Intermediate values of the rating are
less conclusive.
- What does a charting service do that a PC doesn't?
Charts generally contain a fair amount of fundamental information such
as sales, dividends, prior growth rates, institutional ownership.
- Can I draw my own charts?
Of course. For example, if you only want to follow a handful of mutual
funds of stocks, charting on a weekly basis is easy enough. EMAs are
also easy enough to compute, but will take a while to overcome the lack
of a suitable starting value.
- What about wedges, exhaustion gaps, breakaway gaps, coils, saucer
bottoms, and all those other weird formations?
The answer is beyond the scope of this FAQ article. Such patterns can be
seen, particularly if you have a good imagination. Many believe they are
not reliable. There is some discussion in Murphy [ref 1].
- Are there any aspects of technical analysis that don't seem quite
so much like hokum or tea leaf reading?
The oscillator set known as "stochastics" (a bit of a misnomer) is
based on the observation that a stock which is advancing will tend to
close nearer to the high of the day than the low. The reverse is true
for declining stocks. It compares today's close to the highest high
and lowest low of the last five days. This indicator attempts to
provide a number which will indicate where you are in the
declining/advancing stage.
- Can I develop my own technical indicators?
Yes. The problem is validating them via some sort of backtesting procedure.
This requires data and work. One suggestion is to split the data into
two time periods. Develop your indicator on one half and then see if it
still works on the other half. If you aren't careful, you end up
"curve fitting" your system to the data.
The Investment FAQ is copyright © 2008 by
Christopher Lott.
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