Thu 13 Mar 2008
An Assessment of a Mechanical Plan: For Newbies
Posted by ray under Written Plan
I have to admit that much of what I write about caters to the more experienced trader. So, to balance the scales, this blog is for the ‘newbie’.
Ten to Fifteen Percent of my net income goes to continuing education - in the form of e-books, books and seminars. Most fail to add to my bottom line but at least I know what’s out there. Occasionally, I am pleasantly surprised.
The distinguishing factor is not the cost of the item or the mode of delivery: sometimes it’s an e-book that costs US$97.00 (e.g. Forex Trading Strategy), sometimes it’s a course that costs US$6000.00 (e.g. This is a very good course; the one run by http://tradewithpride.com).
The distinguishing factors are: is the material useful and does it suit my personality? Thirty-years in the markets gives me the experience to know what and what is not likely to work; and what is and what is not likely to work for me. The two are linked but not interchangeable.
The newbie does not have the knowledge or experience to make this judgement. So, here are a few guidelines to help you decide if the latest e-book offering is worth following.
The first rule is don’t believe the hype. You won’t make a large fortune from pennies at a cost of US$67.00 to US$167.00. The best you can hope for is a system that will produce a positive expectancy. Let’s go back to my favourite formula for trading success:
(Avg$Win x Win Rate) - (Average$Loss x Loss Rate) = >$1.00
Go through the e-book, looking for this info. If the book doesn’t supply it, program (or have someone program) the rules and test them - most of you would probably use TradeStation or Mestastock.
Let’s say the book provides the data. Examine the data to see what is producing the Expectancy Return.
- If the expectancy is produced by a high win rate on any timeframe other than a very short-term one, then it’s either not robust (i.e. the results will not be replicated) or the results aren’t genuine. In this probability game, you have one of two choices:
- a) a high win rate over a short time-frame with a small AVG$win or
- b) a low win rate over a longer timeframe with a larger AVG$win
In all my years of trading, I have yet to see a successful approach that does not fall into one of the two categories.
Secondly, make sure the entry signals are normalized using a volatility benchmark - usually they are not. This means that once the current volatility fails to match the test sample, the results can be vastly different.
Let me give you an example.
This week I downloaded the newest FX offering. It’s a volatility breakout system: work out an average price; use a price filter above the average to buy and a price filter below the average for a sell. There is a trailing stop rule of 40% i.e. if the market has achieved 40% of the target pips, bring your stop to breakeven.
The author provides:
- Some generic suggestions of what the profit target should be (”30-50 pips’ or ‘75-100′ pips). On a risk:reward basis, the stops are .75:1 (for targets of ‘75-100′ pips) or 1:1 (for targets of ‘30-50 pips’).
- He also provides some TradeStation optimization of various pairs. For example for the AUDUSD, the optimization is an 89 pip profit target with a stop loss of 59 pips and a breakeven stop of 60% (not 40% of the generic rules).
Ok what’s the problem with the system rules? Think about this for a moment before reading on.
The rules will work for the volatility conditions at the time the author wrote the e-book! If conditions change, the suggested parameters will be ineffective.
Let’s take the AUDUSD:
- From March 29 2006 to July 24 2007, the Average True Range (ATR) was 63 (with a standard deviation of 24).
- Since July 24 2007 to date, the AUDUSD’s Average True Range (ATR) has been 120 points (with a standard deviation of 59).
- In short in the past 12 months, the volatility has doubled!
What does this tell me?
- The e-book was probably tested in the post July 24 2007 period. This is a lower probability of pocketing 89 points daily if the ATR is 69 points than when the ATR is 120 points.
- The other reference points all suffer from the same drawback: when conditions change, they don’t apply.
So, let me recap this second point: ensure any advocated system rules normalize its parameters with a volatility benchmark. The ATR is as good as any for this type of measurement.
Thirdly, test the system over a variety of conditions trending, congestion etc. I know some, if not all, will be reluctant to do this. But think of it this way: if you don’t, you have no way of knowing how the system will behave over different conditions.
Finally make sure you have some rules for position sizing, portfolio risk, per contract risk and for the increase and decrease of exposure (as your equity increases or decreases). In other words: make sure you have some meaningful money management rules.



























March 13th, 2008 at 10:59 am
BREAKING NEWS to All Readers
You will be pleased to know that our mentor has been invited back by CNBC tomorrow to appear on a Q & A spanning an hour at Cashflow between 11 am to noontime , Singapore Time (11pm - 12 midnight ET).
With the recent intervention by the FED and the twin evils of Gold and Crude hitting the sky, there will be lots of questions put to our mentor.
Whatever, let us wish Ray : Break a leg!
March 13th, 2008 at 1:04 pm
Ray-san
I like your continuing self education style. Evolve or perish. I have a feeling that there are a more than a few ‘dinosaurs’ in the trading arena that are doomed to become extinct, if they don’t adapt. Also a lot of newbies, prabably latch onto methods that have passed their usefullness.
But, and its a full bodied, big rounded but, that doesnt mean that there isn’t a lot of useful ideas, tweeks, concepts within an older or less efficient trading system. Pick the eyes out of them.
ATR seems to feature a lot on MarketProfile websites as a useful tool. The most recent 10 days ATR is in my obervation is the prevalent version. Isn’t 10 days statistically a little light? I thought 40
periods was better statistically. Or does that lose the ‘most recent flavour’ too much?
Stuart
March 13th, 2008 at 1:10 pm
Dear Ray,This is sound advice for both newbie and oldbie.Volatility is one of my favourite areas of research.A modicum of improvement in this area alone,can really improve bottom line dramaticly.Good luck with the TV gig. cheers Baz
March 13th, 2008 at 1:14 pm
Hi Ray,
Do you have any views on the ‘average’ in ATR calculation - i.e. The period over which the ATR should be measured. I guess where a 14 day ATR is a better sample size the 5 Day ATR would respond more quickly to a hightened volatility regime?
Thanks for all the posts - a great daily read
March 13th, 2008 at 1:29 pm
Hi Stuart
Yep - me too. I think 10 ATR is light if you are position trading. It’s Ok if you are day trading or scalping.
As long as current conditions are similar to the sample, I prefer to use the data encompassed from the most recent extreme of the 1st higher timeframe. I am looking for at least 30 readings.
I’ll put up a chart of the ADUS tomorrow to make this clearer.
March 13th, 2008 at 1:31 pm
Thanks Baz.
TV is something I still have to get used to. I hope I go better than last time! I kept looking away before the camera was ready.
March 13th, 2008 at 1:34 pm
Hi Ryan
Thanks - glad you like the blog.
As long as current conditions are similar to the sample, I prefer to use the data encompassed from the most recent extreme of the 1st higher timeframe.
I’ll post a chart tomorrow to better illustrate.
March 13th, 2008 at 4:55 pm
Come on Ray, slick your hair down, put on brown safari suit and make really good TV info-mercial with lots of golf, sitting by the pool and other trading related life style pastimes. Don’t forget to press the point on how easy it is…..
Stuart
March 13th, 2008 at 5:08 pm
Sounds good Stuart-San.
I’ll make sure I tell them:
* how I never make a mistake,
* hardly ever lose and
* make money hand over fist with 90% winners and a 3:1 Reward to Risk Ratio!
Buffett stand aside!
March 13th, 2008 at 11:20 pm
Ray-san
Just to add to what Stuart-san said: Don’t forget to smile into ‘candid camera’ and say “I’m infallible,” with both arms up!
March 14th, 2008 at 5:09 am
Regarding the FX system mentioned, a trader could modify it and use % of the ATR then fixed amount.
Using a % ATR would make the system more robust in different environments.
Just a thought and obviously needs to be tested
March 14th, 2008 at 8:35 am
Dear Ray,
This post confirmed the concept I’ve known from a friend of mine about how a mechanical trading system is assessed. I myself is an active system developer. I developed myself the system I used in my trading, mostly mechanicals.
My questions is do you ever witnessed a successful mechanical traders yourself in your entire career?
Keep posting about mechanical trading. Your information is really appreciated.
March 14th, 2008 at 9:44 am
MEMO
If you have missed the live session, here is the link at CNBC Asia videos:
http://www.cnbc.com/id/15839263/site/14081545/?tabid=15839801&tabheader=false
March 14th, 2008 at 11:16 am
Hi Sito
I agree - it would be worth investigating.
March 14th, 2008 at 11:18 am
Hi Baggun
Thanks - I’ll see what I can do. Mechanical trading is not my forte.
Yes I have seen and met successful mechanical traders. In fact I believe that one of the best traders in the world is Ed Sekoyta and he is a mechanical trader.