Getting Started Trading Systems Combining Mechanical and Discretionary Trading

Mechanical systems do not work.

Let me rephrase that. Backtested over several years of data, mechanical systems do not show a sufficiently consistent profit and an acceptably low drawdown for the small trader to trade consistently, comfortably, effectively and economically.

To expand on that further, the results of a coded mechanical system might well show periods of excellent profits but, virtually without exception, they will also have draw-downs that most small traders would not be able to tolerate. In addition, most systems tested over several years invariably have considerable periods of losses, usually running over months if not years, plus long runs of losing trades.

If you start trading a mechanical system at the wrong time, you could face months of losses before it starts to turn profitable. Few small traders have the stamina to do that or to sit through more than a handful of consecutive losing trades.

But, you protest, the trading forums, including this one, are full of people using mechanical systems quite successfully. Apparently so, but if you look closely at these posts you will often see a request for someone to program the system so it can be backtested mechanically. None, to my knowledge, have produced consistently profitable results over any meaningful period of time - although if you know of any which have, please point me to them!

So how can some traders claim success with a so-called mechanical system that can often demonstrably be proven not to be successful over the long term and that other traders fail to achieve success with at all?

The answer is that they use discretion. Their own discretion.

If you look at what successful traders do, you'll notice that, almost without exception, they all rely to a degree on their own intuition, feel and instinct - discretion. They may use indicators, chart patterns, Fibonacci levels - all manner of Technical Analysis tools - but the setups and trades are filtered through their own perception of what's happening in the market. These are the traders who consistently make money.

Sure, they have bad days, bad weeks, and they have drawdowns but they have one thing that a mechanical system does not have - a brain. And they use it! All traders have a brain even if they don't all make the best use of it! Although the human brain may not be able to match a computer for sheer processing power it's far better at pattern recognition, fuzzy and deductive logic, at looking at a wide variety of disparate inputs and signals and pulling all these together to form a conclusion.

Mechanical systems with discretion

In my own trading I have found that the way to success in trading lies in combining a set of trading rules, ie a mechanical system with discretion?

This can be incorporated into many trading systems - in essence, use a system or methodology you feel comfortable with but don't automatically take every trade it throws at you. Think about the chart, the price, the setup;
ask yourself how you feel about the trade. Does it look right?

Here's an example. Let's say one of your setups is the RSI hooking down after it's reached an overbought level. Let's say on one occasion that it hooks when it's 1 below the actual overbought level. Do you accept that as a Go signal or not?

If you were trading purely 100% mechanically, you would not. However, if, to you, the other signals look "in good order" then you might "give yourself permission" to take the trade. In other words, don't restrict yourself by waiting for all the Is to be dotted and Ts to be crossed. Take in the wider picture and make a decision accordingly.

Another example - let's say all your setups are firing and you're ready to put on a trade. Before pulling the trigger, take a moment to look at the bigger picture. Okay, the RSI may be well into overbought territory and starting to hook down but, wow, look at that rising trend. The RSI is quite happy to stay overbought or oversold while the market continues in its original direction so does the price look likely to continue or to reverse? Use your judgement. If you're not sure, wait for confirmation that the market has reversed - a chart pattern, a break through a support level, something that adds credence to the system's signal.

Now you're not going to make the right call all of the time - but then neither does any system or trader. The object is to use your skill, judgement and experience to make better calls than a purely mechanical system so you get the best of both worlds.

Now, some of you may be thinking - that's all very well, but I simply can't trade intuitively. That's okay. Some people seem to have a natural instinct for it but most of us must learn it. It is a skill and it will improve with experience. As you learn, you will be looking at and evaluating the charts. You've probably heard this before but there is no substitute for screen time - watch the markets, see how they move and how they react to various situations. Watch diligently and you will learn by osmosis.

Starting out

The first thing you need is a system or method. The Net and trading forums are full of systems. Select one that seems logical and reasonable, one that makes sense to you. Remember, the object is not necessarily to trade every signal in every situation but to look at the bigger picture and make an informed decision about whether or not the setup is valid and is likely to make a good trade.

Many beginners start off by looking for a mechanical system hoping or expecting that it will automatically put them on the road to riches. After a few months' experience, often to the detriment of their trading account, they realise that it's not as simple as that.

While beginners can certainly start by looking at mechanical systems, the acquisition of the necessary skills to interpret charts will take a little time. Remember this - if it was easy, everyone would be doing it. It isn't and they're not. But like most things in life, it is a skill that can be learned and one that will improve with experience.

If you are a newcomer to trading, may I suggest you spend time learning the basics of trading, money and risk
management, order placement and a spot of trading psychology? This is all freely available on the Net, particularly in trading sites and forums such as this.

For more about the inconsistency of purely mechanical systems and the necessity to learn how to actually trade, take a look at Malcolm Robinson's excellent article, The Evolution of a Trader.

The road to a combined system

If you're not sure that you can develop your own discretion, you can build up to it by exercising your judgement in a more, shall we say, practical way. For example, before jumping into a trade, see if the price is near a support or resistance level, a fib level, a recent high or low. If it is, this might suggest that although the basic premise behind the trade is sound, the price may not move very far creating a poor risk/reward ratio.

Check if any news is due that might affect the market. Forex, for example, often moves significantly - and unpredictably - on the release of certain news reports so you need to take care when trading around those times.

You can also use the "look before you trade" principle if you work with several indicators. A purely technical trader might want all his or her indicators to be firing at the same time before taking a trade. If you add a discretionary element to your trading you don't have to do this. You can weigh up the importance of each indicator and even if one is not firing, take the trade if everything else looks right. Or, if one is lagging behind the others but it looks as though it might fire in the next bar or two, you might use your judgement to step in front of the signal and enter early.

You can use your discretion in any situation and apply as much or as little of it as you like. To begin, when your system signals a trade, you might use discretion simply to check the price against support and resistance levels or trendlines. As you gain experience you might take fib levels or pivot points into consideration. As a setup approaches, you might search for candlestick patterns such as dojis or chart patterns such as double tops and bottoms that might confirm the trade or suggest caution.

In essence, what you are doing is using the power of your brain - its reasoning, deductive and intuitive abilities - to adapt your trading method to changing markets. With experience, you will do this naturally, subconsciously. We allow and compensate for narrow-range days, poor volatility, erratic price movement - these and a whole range of other factors that make the market move as it does, factors that standard indicators and technical analysis can't fully take into consideration when presenting their signals.

We can do this - purely mechanical systems can't. Self-adapting and self-optimising systems attempt to do it but they are not consistently successful, and there is a whole raft of Artificial Intelligence, Neural Network and Genetic Algorithm software that aim to analyse markets to the Nth degree to create successful trades but none can match the mind of a trader well-tuned to the market.

Caveats

Like any trading system, it's possible to lose money with using a combined mechanical/discretionary system just as easily as you can make it. To make money, your judgement must be correct and this will only come with practise and experience. However, you can be sure that blindly following a mechanical system will not, in the long term, make you profitable.

Also remember - the entry decision is only part of the trading process - and some would say only a small part at that. However, without a method you have no trades at all so the system remains an essential part of the plan.

By combining discretion to your trading rules you will begin to develop your own trading style. Your decisions and judgement calls will be based on aspects of trading that appeal to you and that you are comfortable with. It can be a self-reinforcing process. As you make successful decisions, you become more confident about them which, in turn, makes you more comfortable with using your discretion.

If you have any questions or comments, please feel free to contact me.
 
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"If you had such a perfect system would you really sell it off at a bargain price, I don't think so."

Conceivably, if you enjoyed analysis and strategy but didnt have what it took to be a good trader, then you might sell systems that you developed.
 
Hi Denny
All systems have drawdowns, whether they're mechanical or not. Just because a discretionary trader can't show you the evidence of his drawdown as easily as a mechanical trader can, doesn't mean it doesn't exist!

Mechanical trading only really comes into its' own when you forget about buying any of the systems that are available, and start doing the work yourself. That way you are clear what the system was designed for, what its pitfalls are, how long drawdowns are likely to last etc. You then have a better understanding of the difference between drawdown & system failure.
You can also design rules to tell you whether or not you should be trading a particular system, like creating a moving average of the equity curve and only trading the system when the curve is above the average.

Most importantly, you mustn't rely on one system - if you run a portfolio of systems that are designed for different market behaviour and different markets, then when one or more of your systems are in drawdown you have others that are hopefully trading profitably, thereby smoothing the equity curve of your portfolio as a whole.

I certainly wouldn't suggest that mechanical trading is the only way that works - just that unless you're very experienced indeed, trying to combine the 2 disciplines into one strategy is pointless & will probably harm performance. If a system trader wants to make discretionary trades then he is obviously able to do so, but why not make them seperately from his system trading altogether?

Simon
 
all trading that is not random entry/exit is essentially discretionary.

a rule is merely a formalised discretion, isnt it ?
( dont enter/exit a trade until A,B,C rules are met, OR until you a Ross Hook, OR you get X% pullback etc )

discretion is in effect a sort of unformalised, or undefined rule.
( the chart "doesnt look right";
A,B,C rules are met, but "I dont like that volume spike";
A,B,C rules are met, but "I dont fancy entering a trade so close to NFP figures") etc.

with some analysis, what starts off as gut-feel discretion, may be formalised into another rule.
one step closer to a mechanical system, but with more sophisticated rules.
:)
 
Ed Seykota, widely regarded as one of the best traders ever (hes returned 60% a year over the last 35 years with 100s of millions under management) and was interviewed in Market Wizards said:

"Over time i have become more mechanical, since (1) I have become more trusting of trend following
(2) My mechanical programs have factored in more "tricks of the trade". I still go through periods
of thinking I can outperform my own system, but such excursions are often self-correcting
through the process of losing money"

This is one of the greatest traders who has ever lived saying he cant beat his own mechanical system,
what chance do the rest of us have?
 
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"hes returned 60% a year over the last 35 years"

Where is this data from? I understood he never publishes such information hence I'm interested in your source.
 
Tuffty said:
"hes returned 60% a year over the last 35 years"

Where is this data from? I understood he never publishes such information hence I'm interested in your source.
Micheal Covel in his book 'Trend Following' says he averaged almost 60% a year between 1990-2000.

We know from Market Wizards that his returns in the 70s and 80s were also atleast that
amount, (if not much more given the inflationary markets at the time).
 
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The reason I feel these systems only work in the past is that this is true for any system even with discretion.That is true except for tape reading. That will always work because the tape is the tape and no matter what happens up or down, sideways, market dullness or volatility the tape always tells the story. Hence real good tape readers will always be able to extract profits.

Livermore said "A battle goes on in the markets and the tape is your telescope"

Wyckoff in his book Studies in tape reading said "The tape tells the present and future of the market. On the other hand the news ticker records what has happened. It announces the cause for the effect that has already been more or less felt in the market. Money is made tape reading by anticipating what is coming-not by waiting till it happens and going with the crowd."

Gerald M. Loeb wrote in his book The Battle for Investment Survival "In my opinion, far and away the most important thing to master in Wall Street is the tape. It is possible to see only the tape, and nothing else, and make alot of money."

Wyckoff once said "Successful tape reading is the study of force (i.e. volume); it requires the ability to judge which side has the greatest force behind it. One must have the courage to go with that side." From Tape Reading For the 21st Century by Clif Droke

I agree that all systems mechanical or discretionary except for tape reading can become obsolete and no longer work in the markets. However, as long as there is a tape to read tape reading will work. I use a discretionary/somewhat mechanical system to determine envelopes for entry and exits but I time my exact entries and exits with tape reading.

Unfortunately, the art of tape reading has been pushed to the back shelf somewhat with the event of all the modern indicators and the computer. Actually, there aren't alot of books on tape reading. The past generation of Livermore, Gann, Wyckoff, Humphrey, were tape readers among other things. Don't see many recent books on tape reading. Clif Droke's book is one.

I think a combination of mechanics, discretionary and tape reading can work well to formulate a trading plan. I try to use all three in my trading.

PT
 
I think Covel may be looking at what he saw with rose tinted glasses as it fits in with what he's selling. It's just that at 60% compounded for 35yrs even with a very modest starting pot equals billions. Also it may have been a model account with no drawings etc. Anyway, thanks for the feedback, Cheers Tuffty.

trendie, I had a thought. Can you paint pictures with rules and will they be as good as a discretionary painters' picture? I suppose a mechanical trader may be like a photographer; it's still an art form but just using a different methodology.
 
Tuffty said:
I think Covel may be looking at what he saw with rose tinted glasses as it fits in with what he's selling. It's just that at 60% compounded for 35yrs even with a very modest starting pot equals billions. Also it may have been a model account with no drawings etc. Anyway, thanks for the feedback, Cheers Tuffty.
Most funds in the Billion dollar range do not compound, they return each years profits to
back to clients, and they dont accept new money either as they have reached there maximum
manageable size.
 
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Tuffty said:
trendie, I had a thought. Can you paint pictures with rules and will they be as good as a discretionary painters' picture? I suppose a mechanical trader may be like a photographer; it's still an art form but just using a different methodology.

yes you could !! ( isnt the "Golden Mean" used to identify the ideal frame ratios ? )
but, they wouldnt possess the element of "artistic" flair that a gifted artist would have.
but then again, once you have experienced many "pictures by rules", you would have the confidence to paint without rules, but those rules would be ingrained by then.

interesting notion, Tuffty.
 
A wise man would take anything Covel says or writes and treat it with the same respect one would treat a report in the National Enquirer.

Also treat the reviews on Amazon with zero regard. Mike gets the bad ones deleted.
 
turtle trader -
This seems like an ill-informed generalisation - there are plenty of systems that are profitable, but they will not work 100% of the time. This is where the intervention is required. You must decide to trade a system based on its' performance & then stick with. Review it periodically and then decide whether or not to amend/continue.
Trying to cherry pick which signals to take may mean you miss a few losing trades, but at the expense of missing some of the biggest winners & getting poor entries on all trades whilst you work out if you should take them.

I agree.......

The term "mechanical trading system" seems to be being used to cover a variety of methods of trading - from very formal to fairly informal.

You could be using this term to refer to something very basic like "Champion Trader" - a commercial system that you have acquired - put your trust in, and started trading yourself, but not designed or tested yourself.

Or you could be referring to a "mechanical trading system" that you have studied to the micro level through the design, coding, backtesting, evaluation and maintenance - yourself - through using software such as Tradestation or Metastock - thus taking a more scientific approach - than relying upon the work and claimed trading results of other system sellers. This would typically be a trading system that produces objective entry and exit signals that you either manually execute yourself, or have fully automated with your broker.

Mechanical trading/mechanical trading systems obviously can/do work - because there is a market for software vendors who enable them - Tradestation, Metastock, esignal, Amibroker, OmniTrader, Proreal-time, AIQsystems - to name just a few.

This is not to say that trading systems will vary in their effectiveness over time - they will because market dynamics can change. This is where the evaluation and maintenance of an MTS comes into play.

Cheers

jtrader.
 
turtle trader - Most importantly, you mustn't rely on one system - if you run a portfolio of systems that are designed for different market behaviour and different markets, then when one or more of your systems are in drawdown you have others that are hopefully trading profitably, thereby smoothing the equity curve of your portfolio as a whole.

Hi TT

What about running one mechanical trading system only - say a trend following system - using tradestation, that you have designed to capture the big moves, and to minimise entries and losses during flat periods of market activity - thus accepting that your system will not be profitable all of the time under all market conditions - but expecting the trending periods that capture the profits - to outweigh the flat/sideways periods where entries and losses were minimised - either intrday or EOD?

Cheers

jtrader.
 
JT

I guess for me it comes down to how much you want to put in to your trading (in terms of time & effort) and how much you want to take out (cash). Such a system might be ideal for a part time trader, who is not reliant on his trading for regular income, but be way too scary on its own for someone who aims to draw a 'salary' from his trading - those flat/sideways periods can go on for a very long time.

It also relies on the system returning to profitability when the flat period is over. Two periods that could be defined as trending can still behave very differently, resulting in your system failing to make any profit in one, although it worked wonders in the other ... but then that comes down to the individual system.

To me a better option, even for the part time trader described above, would be to run at least one more system that's designed to make money in a ranging market. That way, so long as the drawdowns aren't too bad during the 'wrong' market conditions for each system, you can still hope to be profitable during any one period overall.

An alternative might be to test your original system on alternative markets, or with different time frames on the same market. Without getting too caught up in definitions, you could say that equity markets spent pretty much the whole of last year ranging, whilst for much of it, it wasn't too hard to find a trending currency pair. Assuming your trending system worked across each, you would be protected from the drawn out flat period in equities.
If you were to stick with an individual market, changing time frames might provide your answer. Taking EURUSD as an example, the period from Oct-Dec04 was a clear trending period on the daily charts, but if you go down to 15 min bars you can see that a significant amount of that time was ranging, interspersed with some big, short sharp movements that gave it a trending appearance on the higher timescale. Alternatively, May-Sep 04 showed very little trend consistency on the dailies, but if you go back down to 5 or 15 min charts there are some great short term trends. It might be possible to use this to help provide more consistent returns whilst sticking to the one system (although trading at lower timeframes is always going to be more time consuming & therefore not suitable for part time traders).

So as with most things, the more time & effort you put in, the more you can (possibly) take out. It's certainly not as easy deciding not to take the losing trades of one (or more) mechanical systems!!!

rgds
Simon
 
Thanks TT

If trading EURUSD full-time on an intra-day basis - one option is to use just a trend following system - using tradestation, that you have designed to capture the big moves, and to minimise entries and losses during flat periods of market activity - thus accepting that your system will not be profitable all of the time under all market conditions - but expecting the trending periods that capture the profits - to outweigh the flat/sideways periods where entries and losses were minimised?

Another option would be to run an MTS designed to profit from the ranging/flat periods simultaneously alongside the trend following system designed to capture the big moves, and to minimise entries and losses during flat periods of market activity - thus accepting that your system will not be profitable all of the time under all market conditions - but expecting the trending periods that capture the profits - to outweigh the flat/sideways periods where entries and losses were minimised

However, if you run the 2 MTS's together at the same time, when the market is either trending or ranging - the MTS designed for use in the opposite market type - would surely cancel out the the profits (or some of the profits from the alternate MTS). They would, to some extent have the effect of hedging one another.

Therefore, would it be a good idea to have some sort of rule that said - for example - the trend following system is the dominant/primary MTS, and the ranging MTS is the secondary MTS and will only come into play - when it has been shown that the market is not trending (such as after a couple of losing/flat/sideways trades in the trend-following MTS?

The switch back from the ranging MTS to the PRIMARY trend-following MTS could be completed upon a breakout from the range - whereby a signal to produce an exit from any open trades within the secondary/ranging MTS could be produced.

Only one of the MTS's would actively produce signals at any one time, but the primary/dominant trend-following MTS would be active at all times.

Does this make sense?

Would it be necessary to identify one MTS as primary and the other MTS as secondary?

Do you have any ideas as to how a trend-following MTS and a ranging MTS could be used together?

Many thanks

jtrader.
 
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pttrader, Regarding your comments about tape reading. As I see it it is just like any other system, nothing different. If fact you can only trade on the tape in those markets that have it as part of the market structure ; no tape = no tape readers. Where there is tape the tape reader is just exploiting market inefficiencies just like any other trader (mechanical or discretionary). Its interesting that when Livermore first tried his hand on the 'real' market rather than the bucket shops he couldn't profit as the 'tape' in the bucket shop was what you dealt on rather than having to send orders to the market and get them filled.
 
Hi JT

This is where it gets interesting, isn't it? So long as each system has a positive epectancy overall (throughout both trending & ranging periods) then running the 2 together should mean that they are both still profitable & that you get a smoother equity curve. However, if the drawdown in your trending system entirely negates the profit of your (currently) winning ranging system, or vice versa, then you may as well just sit on your hands ... except that you don't really know which market type you're dealing with at the time.

Because it's so difficult to define market behaviour you just have to do your best to design systems that stay out of the market when appropriate & get back in when conditions improve for the particular system, but ultimately just accept that you're going to experience drawdown on each system & run the two together in order to smooth your curve. This is why running as many systems on as many symbols as you can reasonably manage is the best way i'm aware of to provide consistent returns.

Having said that, possibly the next step in managing a mechanical system is to try to define its suitability to current market conditions by ignoring the market itself &, as you say, looking at whether or not it's performing well currently. This is something that i'm just starting to consider, so would appreciate any ideas. I don't believe that just a few losing trades is enough to warrant turning the system 'off', but carrying the idea forward may provide an answer:

Because we are able to backtest a system, we already know how many consecutive losing trades it's experienced in the past - maybe if it exceeds this number in the present we should start thinking about putting it on hold until it starts performing again?
Or how about doing a little technical analysis of the systems equity curve to tell us if it's worth trading? On the face of it, this might seem absurd (that's what I first thought) but looking at some curves, performance would certainly be enhanced by only trading the system when the equity curve is above its moving average. This idea may not be quite as silly as it sounds - markets don't normally just change behaviour overnight, so the system may gradually stop/start working as the market gradually shifts its mood. Perhaps we should start looking for H&S/double top patterns in equity curves?!?!?!

These are very much just ideas at the moment - i've done no quantative research in this direction at all. Whatever we do, i'm sure we'll find that trying to decide whether or not to continue with/ re-start using a particular system will be like trying to pick market tops & bottoms - we just can't do it & will have to accept a certain amount of 'retracement' before our equity curve hits its 'trailing stop' .

Has anyone else tried anything along these lines? (I suspect most people will think that i'm going slightly mad!)

Simon
 
Thanks Simon.

So while as i suggested - it may be possible to link a trend-following MTS directly with a ranging MTS and have some form of switch between the 2 - you think it would be worthwhile to run the two systems simultaneously as seperate systems in their own right - as long as the backtesting results for both had proved that they were, historically, both winners in the long term. This way you are at least spreading the risk between more than one historically profitable MTS?

Many thanks

JT.
 
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I think that each MTS must stand upon its own two feet, and for as long as that is the case it's best to operate both together and therefore spread the risk, yes.

If it is possible to identify ways by which you can put a system on hold whilst it's in a period of drawdown, then that seems like a good idea too - as long as you can test the principle in the same way as you can test the MTS in the 1st place, and as long as you do so to each system on its own merit.

cheers
Simon
 
turtle trader said:
You can also design rules to tell you whether or not you should be trading a particular system, like creating a moving average of the equity curve and only trading the system when the curve is above the average.

Hello Simon,

Thanks for this, could I trouble you with a few questions?

Is this method a widely excepted technique for defining when to trade mechanical systems? Do you have any links to information about this? Or is it something you've discovered and made work for you?

All advice appreciated,
UTB
 
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