June 2004Trading Tip:
Linear Regression Explained by Howard Arrington
A Linear Regression (LR) line is a trend line that is drawn
mathematically so that is represents the 'best fit' for the data
points it passes through. The formulas use the least squares
method to determine the line's placement. This minimizes the
distances between the data points and the trend line.
The algebraic expression for a straight line
is: y = b * x +
a where b is the
slope of the line and a is the
y-intercept. The linear regression formula calculate
both the b and the a values.
This chart shows a linear regression trend line in
its 'best fit' position.
One technique is to draw equally spaced channel lines
at a distance based on Standard Deviation. The Linear
Regression draw tool in Ensign Windows has a multiplier parameter
for the Standard Deviation offset. The following example shows
red channels lines drawn at 2 times the Standard
Deviation. Prices that stay outside of the regression
channel indicate a change in trend.
The next technique that is based on Linear Regression
trend lines, is to calculate a Linear Regression line for every set
of n bars, and determine the price where the
trend line intercepts the last bar in each data set. Thus, one
data point is determined for each bar in the chart, and these data
points are then connected to create a Linear Regression curve, quite
like a moving average. The next chart illustrates
several LR lines that each span a set of 5 bars. The price
where the LR line intercepts the last bar in each set of 5 bars is
marked with a dot. These intercept points are then connected
by the red line to form a curve.
The study in Ensign Windows which is based on the
above technique is called Regression Channel. The center line
is calculated as illustrated in the prior example. Then bands
are added whose distance from the regression center line is based on
Standard Deviation.
The last technique discussed in this article is to
plot the Slope of each Linear Regression trend line that is
calculated for each set of n bars. In
our earlier example with several LR lines, each LR line has a
slope. Some have positive slopes wherein the lines are
ascending. Some have negative slopes wherein the lines
are descending. A change in the slope can be an early
indication that the trend is changing direction.
This example shows the Regression Channel, with the
Linear Regression Slope study plotted in green.
The Linear Regression Slope (LRS) is a plot of
the b values calculated for each set
of n bars. In the last 3
illustrations, n had a value of 5. This
small set size makes for a choppy channel and a choppy LRS.
The lead article in this newsletter is a better example of how the
LRS will look on a chart, and the set size parameter will be more
useable when in the neighborhood of 10.
Ensign Windows users who would like to investigate the
Linear Regression Slope study would select the Regression Channel
from the study list, and check the Plot Slope (LRS) check box on the
study property form. The LRS will be plotted instead of
the Regression Channel. Upper and Lower bands may be
added to the plot.
Mail Bag:
'The addition of volume to the Tick charts has become an
invaluable tool. As I believe volume is often a leading
indicator of price, I use volume extensively to make
decisions. With the reduced ES e-mini volume of late, being
able to monitor volume on a tick chart with the Chaikin indicator
study had added a whole new dimension to trading with tick
charts. Additionally, the Volume bar features has again added
another dimension to viewing price action and, along with contract
volume on ticks, aids greatly in making trading decisions.'
-A. Gallo 06-28-2004
'Thank you for this product as well as your commitment to traders
and their success in the markets. The Statistics page is one
of many examples of this. What an amazing tool at my
fingertips! It has aided me in selling the high of the day, on
several occasions this year, as this was made for months between
12:30 and 1:00 pm. This still occurs from time to time but the
market environment has changed some. It has gotten more choppy
and less trendy. My trading style has changed to accommodate
this and to take advantage of the large overnight gaps that are
occurring in the grains markets. So most of my positions are
now being taken or exited near the close.' -J. Shea 06-19-2004
'Thanks for providing us with the very best charting software
available and with absolutely the best support. Trading
is a hard nut to crack..... Ensign Software gives me the
edge.' -B. Davis 06-16-2004
'Impressive support! Thanks you for the amazing
response. What you've implemented will go a long way to making
the trading strategy much easier for the client to use. I'm
sure she will be impressed by what you've done to help out.'
-I. Vanier 06-12-2004
'I have received your latest newsletter where you mentioned
Bradley siderograph and it seems to me that you are interpreting it
somewhat incorrectly. You wrote "It denotes patterns, trends
and the timing of swing tops and bottoms." Consensus among
financial astrologers is that Bradley siderograph indicates only
turning points within about +/- 6 days and quite often they are
inverted. I don't know how familiar are you with astrology and
with how BS is calculated but it can not reliably predict the
direction, tops, bottoms etc. But those turning points are
quite often correct (if you are investing long term) even when
sometimes inverted. Actually, there were a number of different
models of the siderograph created in recent years and they were
tuned to different markets. But even as an astrologer I have
to say you will get more useful information just by putting a moving
average on the chart.' -A. Klouda
06-04-2004 |