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Playing_a_Game_You_Can_Win
| Playing a Game You Can Win
Imagine a simple coin-tossing game where you win whatever you
stake if heads comes up, lose what you stake if tails comes up,
and you are charged 1% of your stake each turn to play. Can you
win money at this game? If you are familiar with the concept of
expectancy, then you will probably answer ‘No’ since over many
turns the amount won will be equal to the amount lost (assuming
the coin is a fair one) and after factoring in the 1% cost of
playing you will lose money overall.
In fact, there is a way to win this game, and that is to
understand that the longer you play, the more you will lose, so
the optimum strategy is to bet everything you have on just one
toss of the coin; just like Ashley Revell did when he sold
everything he owned, took the $135,300 to Las Vegas, and bet it
all on ‘Red’ on one spin of the roulette wheel. Mr. Revell was
fortunate and he won, but I am not recommending that you bet
everything you have on one trade!
Obviously risking everything on one trade is not a useful
strategy since we want a game we can play for long periods of
time to generate a consistent income. So how can we change the
game so that we can win? There are three aspects to the game
which can be adjusted to increase our chances of winning
consistently:
• We can tip the chance of a winner in our favor from 50/50 • We
can increase the size of the payout from 1:1 • We can reduce the
cost of playing the game
Tipping the chances of a winner is not possible in a fair coin
toss game, but it is possible in trading. There are two ways to
approach this: identify conditions that are more favorable to
your winners and include them in your system definition, or
identify circumstances where a loser is more likely, and skip
those trades. For example, if you notice that most of your
winners are entered on days where the overall market has moved
in the same direction as your trade, then only enter trades when
the overall market is moving in the correct direction. This
means that your trade is in the same direction of the overall
market, rather than against it.
Another example might be that trades that are entered just
before major news announcements, like earnings calls, often get
stopped out as losers due to increased volatility, so you should
skip those trades.
There may be many patterns of winners and losers that you can
identify for your own systems and careful study of past trades
is definitely worthwhile. Note that we do not want to increase
our win percentage too significantly (i.e. to greater than 60%)
since this would indicate that we have ‘curve-fitted’ our system
to historical results that are unlikely to continue into the
future.
It is also important to note that for some types of trading
(i.e. long-term trend following strategies) it may not be
possible to have a win percentage that is greater than 50% (and
it may be much lower) and that is where the second aspect of
improving your system comes into play: the average size of
winners versus losers.
Increasing the size of the payout so that the winners win more
on average than the losers lose depends on the way you handle
your stops. Having large winners in relation to losers can make
up for a low win percentage, and mean that you will still make
money playing the game. One method is to have a trailing stop
that moves up as a trade becomes a winner. If you have fixed
stops for losing trades that limit losses, but trailing stops
for winning ones that allow winners to grow, then you are
increasing your chances of your average winner being larger than
your average loser. Generally it is better to be strict on
losers by having tighter stops that keep losses to a minimum and
generous with winners by having stops that allow profits to
grow. In any case you want to make losers small and winners
large, so never add to a losing trade – that would be doing the
opposite of what you want to achieve.
Lastly, reducing the costs of trading is probably the simplest
change you can make, and can mean the difference between winning
and losing overall – especially for systems that have lower
expectancy. There are many online brokers now that charge 1c per
share for equity trades (and comparably low fees for other
instrument types) and there is no reason why you should be
paying more than this if you are trading electronically.
Every trader should do whatever they can to maximize the
expectancy of their trading system or method by considering each
of the 3 aspects just described. If we do some, or all, of these
things then the amount we win now becomes a factor of how much
we stake, and how often we play because we have created a true
‘edge’ where we know that the system we are trading should make
money (if traded accurately). Calculating the expectancy of your
trading system or method tells you whether you are playing a
game you can win, and is a very important piece of information
that every trader should know before they risk real money.
If the game is rigged against you because your trading methods
lose money regardless of how accurately you implement them, how
can you ever be a successful trader?
About the author:
Paul King is owner and head trader of PMKing Trading LLC, a
Vermont-based proprietary trading company founded in May 2002.
Paul has published a series of eBooks and articles about what he
considers to be the important aspects of trading.
Visit www.pmkingtrading.com for more details.
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