Contents
Introduction
A trader is prone to deviate from his trading plan whenever he is doing either exceptionally well or having a losing streak or a big single loss. Capping your portfolio is an effective technique to dodge many psychological pitfalls related to money management.
What I do is I calculate the expected or estimated yearly percentage gain of my portfolio based on my own past results. The trick is how I treat and weight my losses, wins and initial risk. It’s a psychological trick that helps me stick to my plan and thus achieve superior results.
The system utilizes my actual losses but also includes the intial risk of the winning trades. Those same winning trades are then capped -only on paper- at roughly three times my goal risk per trade. This means I let winners run, but for the portfolio calculation of the forward performance, they are capped.
My goal is to always make sure that this capped system has a positive expectancy no matter what.
Whenever you score a big win exceeding three times your goal risk (stop loss) it is simply treated as a regular 3 times your goal risk win (short: 3R) and nothing more.
Here is an real world example of my past trades illustrating the concept.
The dotted magneta line is the mean value of your real losses aka stop loss hits (dark magneta bars) and the intial risk of winners (light magenta bars). The dotted blue line is the capping threshold and the dotted black line is your actual average outcome of each trade. Blue bars are obviously the winning trades.
Most of my wins during this -red hot- phase have been larger than the capping threshold. But I don’t care much about them. All I care about is if my system would be profitable IF those big winners ended at the dotted blue line.
While writing this article I actually made a nice observation. A trading analysis reveals larger losses and risks after the two big wins in the middle. So apparently even when you are experienced and aware of all this stuff you are still prone to be influenced by emotions released by big wins.
Small scratch wins and losses are ignored because otherwise you would be able to improve the expectancy too much by getting out with small wins or losses. A habit you don’t want to develop as a trader. I work with 0.35% as my scratch trade threshold but my wins are rather large so you might have to adjust that down if you tend to hold more than 4 or 5 stocks in your portfolio at any given time.
The capped portfolio takes care of the following psychological obstacles
- You can’t afford to trade sloppy after a big win because that win doesn’t create any cushion on paper. You are forced to stick to your rules!
- If you risked more than your goal risk to score a big winner the expectancy will actually go down despite scoring a monster win. You can’t sweep any risk you took under the carpet!
- A big loss can’t be compensated by going risk-on mode with the hope to score a big win. You are forced to refrain from revenge trading!
- It will force you to give your trades room to breathe as you won’t get rewarded for small wins or breakeven trades.
- It uses the actual portfolio percentage wins and losses so you can’t trick it by trading small size for a while as it is the case in a classic 3R approach. It encourages you to trade your normal position sizes.
It completely turned around my trading and forced me to pay almost all my attention to losses and risk and only a fraction to my winners.
The idea was born on a regular trading day when I read my mantra out loud before the bell as usual. Here is my mantra which I got from the web years ago:
By focussing on your losses you completely outwit yourself. This method allows you to dodge a myriad of psychological issues in the process. In the following I’ll show you how to calculate it.
Calculation of the yearly estimated percentage gain
Alright so here is where the fun starts for some and ends for others. You actually have to crunch some numbers and this is best done in Excel or a similar tool.
Expectancy per Trade (Expectancy):
Expectancy = [ ( WR * MW ) + ( LR * MR ) ] * ( GR / AMR )
WR: Winrate defined as number of wins divided by the sum of wins and losses.
MW: Mean of your percentage wins which are capped at three times GR
LR: Lossrate defined as the number of losses divided by the sum of wins and losses or simply 1 minus WR.
MR: Mean of your cumulative percentage losses and initial percentage risks of your winners. This equals GR if you close out every single trade at exactly your stop loss. In reality this is hardly the case.
GR: Your predefined maximum risk per trade. In a perfect world this would equal MR.
AMR: Absolute value of MR
You can now use the expectancy and calculate an estimated yearly performance in order to get a closer-to-real-world number you can better relate to.
First, you have to calculate the estimated number of trades per year (trading opportunities) as follows:
Trading opportunities (per year):
Opportunity = ( NT * 365.4 ) / DOY
NT: Number of trades so far this year
DOY: Current day of the year
Next, you’ll get the yearly forward performance by applying the well-known equation of compound calculation of interest. You can also calculate a monthly, weekly or any other duration based factor by appropriately modifying your number of trades above.
For a monthly forward performance you simply replace 365.4 with 30.5 (the average days per month) and use the current day of the month instead of DOY.
Yearly Performance estimate:
[ 1 + ( Expectancy / 100 ) ] ^ Opportunity
If you hate decimals you can turn this value into a ‘real’ percentage value by multiplying it by 100 and then substract 100 from the result, voilà!
I like to calculate performance estimate as a yearly value (mostly for tax purposes) and I use this as my baseline performance. From my experience this will be a very robust estimate once your expectancy value is based on a multiyear trading history! The wins exceeding the capping threshold are then just the icing on the cake (2019 is 20% cake and 80% icing, awesome year).
I also track this metric as a rolling average over the last 10 trades in oder to have a more dynamic view at my portfolio. This allows me to apply a neat “on fire alarm” as follows:
Whenever the black line is above the blue line in the graph posted above you know that you are red hot.
I reduce my trading size whenever that happens or I start to realize some more gains into strength. This seems counterintuitive but it works like a charm.
CPA is an awesome method for investing beginners. Apply it and tell me if it helps you stick to your rules. All you need are columns of your percentage wins, losses and the initial percentage risk (stop loss) of the wins.
Once you have your capped portfolio running you only monitor your expectancy number and ignore your actual equity curve. Doing this alone solves many psychological pitfalls.
In a follow up article I’ll show you a supplementary technique to evaluate if your trading results are statistically relevant or just by chance.
