Stop Loss - what is it?
A Stop Loss is a price
level at which you would consider selling your investment. It's purpose
is to protect your investment
capital by protecting profits, and limiting losses.
But, how useful is it?
Example#1 - BNB (Babcock n Brown)
Take
a look at the price chart of Babcock and Brown (code:BNB) at right -
click on the image for a larger version that is easier to see.
BNB fell some 84% over about a year in late 2007 and early 2008. All
the way down, investors in this stock had an opportunity to exit the
stock before it delisted in June 2009 - gone! By January 2008 when the
BNB share price showed a "Lower Low" on the price chart, a down
trend was confirmed.
Anyone with a Stop Loss level set at maybe $25 or
$20, could have
triggered a sale and held onto a lot of their capital by minimising
losses.
Example#2
- TLS (Telstra)
Take a look at the price chart of Telstra
(code:TLS) at right
- click on the image for a larger version that is easier to see.
TLS has had three tranches of public float since 1999 when the share
price touched $9 - the floats referred to as T1, T2 and T3. By 2010 the
share price had fallen below $3!
Even though brokers and analysts were recommending that the public take
up each float option and purchase the stock, the share price has
continued a down trend over at least a 10 year period. Whilst any stock
is down-trending, many traders would not buy it. Anyone who did hold
TLS
could have set a Stop Loss at a number of price
points on the way down
in order to liquidate before further price falls. The price chart shown
here shows TLS in a down trend - in which most
traders would not invest
(except for very short term gains on the short upswings).
How to calculate a Stop Loss level?
Unfortunately, there are many correct answers
to this question, and they are all different. Just some of the possible
methods (with
comments) include:
- A specific percentage fall in price - eg.
10%.
This arbitrary method is very fallible because a stock might find
technical
support lower than 10% below current price, and then rally
upwards to
new highs.
- Chart pattern - at a recent Support level.
This is a clever approach, and utilises the technical analysis notion
of price Support levels (see more details about Support and Resistance).
It is also believed that support can occur at the base of a tall white
candle (ie. a Big White). For more information about the related topic
of
chart patterns, see relevant eBook
Articles on Technical
Analysis, or the "Blue Chip Price Chart Secrets"
handbook (at right).
- Count
Back Line (CBL)
This tool was made popular by Daryl Guppy. See
details below.
- Technical chart indicators - eg.
Parabolic SAR, and Wilson ATR Trailing Stop. Along with chart
patterns,
this is one of the more clever approaches because the distance of the
Stop Loss level away from the price can be automatically calculated by
the indicator, and is based on recent price activity.
ATR chart indicators to determine a Stop Loss
Some people believe
that an automatic approach to calculating the Stop Loss position, is
simple, and as good as any. By using a technical chart indicator, your
price chart can be automatically updated each day you look at it, and
the value to use for the Stop Loss is shown on the chart without having
to think about it. It is clear-cut, and there is no
subjectivity.
Consider this. In normal healthy
trading a stock will whip saw up and down by a certain amount. And over
time, we can measure the amount of price variation up and down over
several trading days or weeks - we call it Average True Range
(ATR). Now if the stock falls by more than about 2 or 3 times the ATR,
then it is outside it's normal behaviour, and it might be weakening and
starting a down trend. So if we can flag this increase in volatility
(ie. the increase in the range of the price), then we can identify
possible weakness before it takes hold.
Now this approach makes a lot of
sense.
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More Information
Slide presentations - There
is some preliminary and basic information in some of the
slide presentations that Robert has prepared and delivered at various
meetings.
eBook Articles - Share
Market Toolbox Members can see more details in the following eBook
Articles:
(Toolbox non-Members can see the "Page 1" of these Articles from the Master
List page.)
Robert writes information from time to time about
the market and investing. If you are not a
Toolbox Member, you
can
register to receive useful free information as it is published.
Privacy ensured, unsubscribe anytime.
See
the Testimonials - the things that people say about the
Toolbox and more.
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Terminology
There are a number of terms that are used in the text at left,
including: Stop Loss, Support, Parabolic-SAR.
There is information on these in Brainy's eBook Articles. See the Master
Index list for details.
Or, search
the
eBook Articles.
The Share Market
- more information about the market and investing and trading.
The toolbox is an arsenal
of weapons to help you tackle the share market.
See a list of contents on
the Toolbox
Gateway page.
Robert
Brain provides various support to both new and
experienced traders and investors.
Who
is Robert Brain?

And whatever you do,
beware of the sharks in the ocean!
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Some samples - Average True Range (ATR)

Many of the
available chart indicators for stops are based on Average True
Range (ATR). The ATR is a dollar value which describes how
far up and down the share price has fluctuated in recent trading
sessions. A common default value is to calculate the ATR over a 14-day
period on a daily chart (or over 14 weeks on a weekly chart).
For
example, let's look at a weekly chart of BHP as in
the sample price chart at right with the share price shown as
candlesticks in the lower half and the ATR indicator in
the upper half (click on the chart for a larger image).
Note that BHP
was trading between about $35 and $50 until it crashed to $25.
The ATR indicator in the upper portion of the diagram shows that the
BHP share price was moving from week to week within a range of about $3
to $3.30, and then the ATR value increased to over $4 with the volatile
share price move downwards in September-October.
 The
calculation for ATR is not a simple and straightforward
calculation; but the chart indicators do all the calculating for us.
The second diagram at right is a weekly line chart of the Macquarie
Group share price in 2009 as it raced upwards from below $20 to above
$55 (click on the chart image for a larger version).
The row of dots
that rises across the chart is the Wilson
ATR Trailing Stop chart indicator, based on a multiple of
the ATR value of Macquarie Group. The idea is that near the right-end
of the chart in early October 2009 when the share price was in the $50
range, the row of dots is positioned at $49.13, and basically says "if
the share price falls to this value tomorrow, then the Stop Loss value
is triggered and we should sell". This indicator can be
easily adjusted to cope with more volatile, or less volatile,
stocks.
The Count Back
Line (CBL)
The
Count Back Line (CBL) is a volatility based charting tool developed
by Daryl Guppy. It can be used on end-of-day data when trading both
long and short, and can be used to assist with each of: setting a stop
loss, trade entry and trade exit. The
CBL should not be used in isolation; but with another tool for
confirmation (eg. simple trend line, or an MMA like the GMMA).
Simple
CBL - The first price chart sample at right shows a daily
price chart of Commonwealth Bank (CBA) in March 2009. Our strategy said
to buy this stock next day (12 March), so when studying this chart on
11 March we identified the most recent
highest high and placed the CBL
tool (in BullCharts
software) on this candle - indicated with the asterisk above
the candle. Then the CBL tool basically goes back to the on a candle
(10th March in this example), then goes back one more last lower
lowlower
low (on 9th March). The value of the CBL Stop
for a long position (the
"Long CBL Stop") is then the low of this candle - which is indicated as
$26.43. However, this simple determination is not so simple when
the previous candles are not consecutively lower as in this example.
View the next sample price chart below right.
Non-simple
CBL - This second example is a daily chart of National
Australia Bank (NAB)in late March 2009. Note the following steps to
identify 
the
Long CBL
Stop level:
- Identify the most recent highest high (2 April).
- Spot the very bottom of that candle, then run your
eye horizontally back to the most recent candle with a lower low
(1st
April), and run
your eye to the very bottom of that candle (this is the first recent
lowest low).
- Now look back in time for the next candle that has a
lower
low - on 25 March. The low of this candle is the Long
CBL Stop level.
See more information about the Count Back Line in Brainy's eBook (PDF)
Article TA-6250, "Daryl Guppy - Count Back Line
(CBL)" (Toolbox Member password required, otherwise
non-members can see Page 1 here).
Chart indicators for stops
Some of the more common chart indicators that are used to determine
Stop Loss levels include the following:
- Elder's Chandelier Exit
- Elder's SafeZone
- JB Trailing Stop
- Parabolic SAR (Stop and Reverse)
- Wilson ATR Trailing Stop
- JB Volatility Profit Taker
- NW Short Trailing Stop (ADX)
- Chande Volatility Trailing Stop.
Initial Stop
This is the first Stop Loss
level that is calculated at purchase time. It's purpose is to identify
the point at which you would exit the stock if the purchase decision
turns out to be a bad one. Traders tend to purchase a stock in the
anticipation of a rise in price. But if the price falls, and the
purchase decision is proven wrong, then it might be prudent to exit the
position promptly.
Trailing Stop
After a stock purchase, and after the share
price rises far
enough, it is time to take the Initial Stop
position and raise it to protect some of the earned profits. It then
becomes a Trailing Stop, and it should be reviewed
and raised every few days (or every week or two) to continue to protect
more and more profit.
Implementing your Stop Loss
In order to implement a Stop Loss, there are
two basic approaches:
- Mechanical Sell
- Place a conditional sell order into the market so that if the stock
actually trades down to your Stop level, then a Sell order is
triggered, and (hopefully) the stock is sold asap. Note: A conditional
sell
order is not guaranteed unless explicitly arranged with the broker.
- Discretionary Sell -
Monitor your stocks periodically (according to your written Trading
Strategy), and if the stock closes below the Stop Loss
level, then consider
selling in the next trading session.
More information?
For more details about Stop
Loss, see the Share Market Toolbox links at the top
of the column at right.
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