Where to Put a Stop Loss

It is virtually a "law" of trading in the stock market thatmonth or more to lock in gains of 10% to 20% or even
wherever you place your stop loss, it will occasionallymore.  However, you may have to loosen the stop a
be triggered by a stock just before it resumes its climblittle for more volatile stocks and for regular holding
to higher levels.  That is just something to beperiods of more than 15 days.  For longer-term
expected if you use any stop-loss.  Unfortunately, notinvesting, for example, a stop that is up to 6% below
using a stop-loss is asking for trouble of a muchthe highest low reached by the stock since it was
greater magnitude, and the market loves to rewardpurchased can be very effective.  A stop that one L
the foolish, lazy, or stupid, with the just recompense oftrader experimented with and found to be very useful
their behavior.  It makes no difference if you set thefor intermediate-term trading is one that is set 4%
stop at 10% or at 3% from the low, high, or close. below the highest low.  In use, it was infrequently
You can use stops that are volatility-based, usetriggered by a whipsaw and it did not give up much of
Fibonacci retracement ratios, Gann analysis, pivotthe gain of the bigger moves.  However, it would also
points, percentage declines, or any other approach. give up 4% or more of the smaller 8% moves.  That
No matter how sophisticated your mathematics is, youis why some traders focus on stops of 3% or less
will often find you have sold for no good reason otherbelow the highest low.  The tradeoff was the greater
than the occurrence of a temporary price spike thatfrequency with which a person is needlessly stopped
was just sufficient to trigger a stop loss -- your stopout of a rising stock.  It would be best if you worked
loss.  Learn to live with itout a personal stop-loss system, one with which you
On the other hand, you can control risk and havecan be comfortable.  
some say about the probable frequency with whichIf you want a reference point other than the highest
you will be ejected from a position because of such alow, the following may be of help.  A test of all the
spike.  The further your stop is from recent pricestocks in The Valuator showed that the average low
action, the less likely it is that it will be triggered. was 1.7466% below the average high and .882%
However, the further your stop is from the price action,below the average close.  This information can be
the more risk (downside price excursion) you are goingused to place the stop relative to the highest high or
to have to tolerate.  Not using a stop at all means youhighest close of the stock since its purchase.  Thus, if
are willing to accept unlimited risk.  Using a "tight" stopthe stock spikes up, the stop will lock in more of the
means you are willing to tolerate very little risk but yougain.  This works best when the stock makes a
dramatically increase the chances that even a minorseries of new highs, each significantly higher than the
spike will eject you from the position.  The tighter yourprevious one.  However, a 1-day spike may cause
stop, the more ejection-causing spikes will occur in anyyou to be stopped out the following day if the stock
given time period.  The only way to resolve thisquickly returns to more "normal" levels.  Walk away
dilemma is to find the best tradeoff between anfrom stocks that often spike down.  The specialist
acceptable frequency of unnecessary ejections andmay simply like to "gun" the stock in order to take out
an acceptable amount of loss that you incur becausethe stop-loss orders waiting at the lower prices.  That
of that ejection.  In other words, you must find theis, the specialist temporarily drops the stock price to
compromise that induces the least amount of paintrigger the sell orders associated with the stops so he
(psychological or financial).can buy those shares at the lower price and sell
Magee and Edwards (Technical Analysis of Stockalmost immediately afterwards at a slightly higher
Trends) teach that a good stop based on closingprice.  When considering the purchase of a stock that
prices is one that is placed 3% below a risingoften spikes down, the trader should try to place the
trendline.  The stop is triggered only if the stockstop just outside the specialist's spiking comfort zone. 
closes at or below the stop.  However, if a traderIf such a placement requires the assumption of too
intends to sell on the basis of intra-day price activitymuch risk, find another stock.  I prefer to concentrate
rather than on the basis of closing prices, they suggeston stocks that rarely spike.  Look at charts and notice
that the stop be placed 6% below the rising trendline. the length and frequency of downward spikes.  Try
Below the trendline or below the most recent minor dipto determine the percentage drop these spikes
is usually the best place for a stop.  However,represent.
sometimes there is no trendline or obvious recentA volatility-adjusted stop has a more universal
minor dip.  That is when you must use a mathematicalapplication than a simple percentage stop because in
stop.  Either a simple percentage based on theaddition to adjusting for volatility it also adapts to the
highest high, low, or close since you purchased, or atime period of the particular "analysis unit" used
volatility-adjusted variable stop placed relative to the(15-minute price bars, 30-minute price bars, daily price
highest high, low, or close since you purchased willbars, and so on).  Rigid percentages cannot do either,
serve the purpose.  Magee and Edwards, Weinstein,but they are easier for the non-mathematician to
Schwager, Murphy, and many others use trendlines,calculate.  If you are trying to compute your own
dips, or moving averages as a reference for placing astop-losses and you do not have a mathematical
stop.  Rising trendlines follow the lows, dips arebackground, you might do well to use a stop loss
nothing more than significant recent lows, and movingcalculating tool (do a Google search on "stop loss tool"
averages generally follow a rising stock somewhatand follow the trail) or simply make appropriate
below its recent lows.  Therefore, it also makesmodifications to the 2.3% rule.  That is, if your stops
sense, in the absence of all of these, to use the recentare triggered too frequently before upward moves
highest low as a reference for placing stops.  With nocomplete when you follow the 2.3% rule, change it to a
trendline or dip to use as a reference, you could simply3%, 4%, or whatever.  However, we believe the
place your trailing stop 3% or 6% (or some othervolatility-adjusted stop loss is not only more
distance) below a moving average that closely followssophisticated but also more effective.  Now, consider
the trends of significance to you, or even below thethe following.  
highest low achieved by the stock since yourThe stop is not necessarily your sell discipline. 
purchase.  However, it is definitely your safety net.  It will
The anticipated average holding period has a very bigpreserve assets if you are not paying attention to your
impact on how tight your stops are going to be.  Forstock's behavior during the day.  If you do not have
example, the "sweet spot" for the 2.3% rule is about 10time to be riveted to the etchings the stock market
to 15 market days.  The short end of themakes across your computer's screen, you only need
"swing-trader" spectrum is about 3 days or less (ato take about 10 minutes to go through your positions
large number of traders focus on holding periods of uponce a day (even while the market is closed) or once
to about one week) and the long end of the spectruma week (even on weekends) to set your stops. 
is 8 to perhaps 10 weeks.  The remaining swingThen you can ignore the market until you make your
traders focus on the time frames in between.  At thenext stop adjustments.  However, if you happen to
very short end, the 2.3% rule allows too much of abe watching your stock and it does not "behave" like it
decline relative to the expected gain.  However, itshould, simply remove the stop and sell the stock.
works well when you are trying to lock in a two-weekCopyright 2009, by Stock Disciplines, LLC. a.k.a.
move involving a 4% to 10% gain.  If the stock is notStockDisciplines.
too "wild," it will also work beautifully for moves of a