Using Two Popular Oscillators: Slow Stochastics and Relative Strength
Two of the more popular computer-generated technical indicators are
the Slow Stochastics and Relative Strength Index (RSI) oscillators. (An
oscillator, defined in market terms, is a technical study that attempts
to measure market price momentum - such as a market being overbought or
oversold.)
I'll define and briefly discuss these two oscillators, and then I'll
tell you how I use them in my market analysis and trading decisions.
Slow Stochastics:
George Lane has been called the father of the stochastic indicator.
I met this gentleman a few years ago. He and his wife still attend and
participate in trading seminars around the U.S. Lane's basic premise is
as follows: During periods of price decreases, daily closes tend to
accumulate near the extreme lows of the day. Periods of price increases
tend to show closes accumulating near the extreme highs of the day. The
stochastic study is an oscillator designed to indicate oversold and
overbought market conditions.
Some technical analysts, including me, prefer the slow stochastic
rather than the normal stochastic. The slow stochastic is simply the
normal stochastic smoothed via a moving average technique. The slow
stochastic, like the normal stochastic study, generates two lines. They
are %K and %D. The stochastic has overbought and oversold zones. Lane
suggests using 80 as the overbought zone and 20 as the oversold zone.
Some technicians prefer 75 and 25. I like to use the 80-20 figures.
Lane also contends the most important signal is divergence between
%D and the commodity. He explains divergence as the process where the
stochastic %D line makes a series of lower highs while the commodity
makes a series of higher highs. This signals an overbought market. An
oversold market exhibits a series of lower lows while the %D makes a
series of higher lows.
When one of the above patterns appears, you should anticipate a
market signal. You initiate a market position when the %K crosses the
%D from the right-hand side. A right-hand crossover is when the %D has
bottomed or topped and is moving higher or lower and the %K crosses the
%D line. According to Lane, the most reliable trades occur with
divergence and when the %D is between 10 and 15 for a buy signal and
between 85 and 90 for a sell signal.
Relative Strength Index:
The Relative Strength Index (RSI ) is a J. Welles Wilder, Jr.
trading tool. The main purpose of the study is to measure the market's
strength or weakness. A high RSI, above 70, suggests an overbought or
weakening bull market. Conversely, a low RSI, below 30, implies an
oversold market or dying bear market. While you can use the RSI as an
overbought and oversold indicator, it works best when a failure swing
occurs between the RSI and market prices. For example, the market makes
new highs after a bull market setback, but the RSI fails to exceed its
previous highs.
Another use of the RSI is divergence. Market prices continue to move
higher/lower while the RSI fails to move higher/lower during the same
time period. Divergence may occur in a few trading intervals, but true
divergence usually requires a lengthy time frame, perhaps as much as 20
to 60 trading intervals.
Selling when the RSI is above 70 or buying when the RSI is below 30
can be an expensive trading system. A move to those levels is a signal
that market conditions are ripe for a market top or bottom. But it does
not, in itself, indicate a top or a bottom. A failure swing or
divergence accompanies the best trading signals.
The RSI exhibits chart formations as well. Common bar chart
formations readily appear on the RSI study. They are trendlines, head
and shoulders, and double tops and bottoms. In addition, the study can
highlight support and resistance zones.
How I employ Slow Stochastics and the RSI:
First of all, these two oscillators--especially the RSI--tend to be
over-used by many traders. As you just read above, some traders use
these oscillators to generate buy and sell signals in markets -- and
even as an overall trading system. However, I treat the RSI and Slow
Stochastics as just a couple more trading tools in my trading toolbox.
I use them in certain situations, but only as "secondary" tools. I tend
to use most computer-generated technical indicators as secondary tools
when I am analyzing a market or considering a trade. My "primary"
trading tools include chart patterns, fundamental analysis and trend
lines.
Oscillators tend not to work well in markets that are in a strong
trend. They can show a market at either an overbought or oversold
reading, while the market continues to trend strongly. Another example
of oscillators not working well is when a market trades into the upper
boundary of a congestion area on the chart and then breaks out on the
upside of the congestion area. At that point, it's likely that an
oscillator such as the RSI or Slow Stochastics would show the market as
being overbought and possibly generate a sell signal - when in fact,
the market is just beginning to show its real upside power.
I do look at oscillators when a market has been in a decent trend
for a period of time, but not an overly strong trend. I can pretty much
tell by looking at a bar chart if a market is "extended" (overbought or
oversold), but will employ the RSI or Slow Stochastics to confirm my
thinking. I also like to look at the oscillators when a market has been
in a longer-term downtrend. If the readings are extreme- - say a
reading of 10 or below on Slow Stochastics or RSI- - that is a good
signal the market is well oversold and could be due for at least an
upside correction. However, I still would not use an oscillator, under
this circumstance, to enter a long-side trade in straight futures, as
that would be trying to bottom-pick.
These two oscillators are not perfect and are certainly not the
"Holy Grail" that some traders continually seek. However, the RSI and
Slow Stochastics are useful tools to employ under certain market
conditions.
Jim Wyckoff
TradingEducation.com |