Turok,
I'm not sure how hard it would be, but if easy for you I would love to see the results of the following changes to your test (shown in your spreadsheet):
1) Start every initial trade with a fixed 1000 shares.
2) Use a fixed multiplier of 1.1. In other words, have the net position AFTER the first flip be equal to 1100 shares, upon a second flip the position will be 1210 shares, etc.
3) With these changes, the share size doesn't ramp up nearly as quickly, thus you can more safely use the suggested "max 11 flips" as the stop loss exit criteria for trading during that day, and see what the results are.
If this is relatively easy to do, and you don't mind, I would be interested to see the results of this in the same spreadsheet format as you have posted the latest results.
I just found this thread and the prior linked thread today, and I sure appreciate all of the thought and discussion that has gone into it so far. This is the kind of thoughtful discussion that makes ET worthwhile, despite having to frequently dig though a lot of crap (on other threads) to get to this sort of interaction. I don't think this ongoing thread would have been thought stimulating if it weren't for abogdan's willingness to share his overall idea, as well as to welcome the views of 'opponents' of his idea and the occasional ET idiots that never have nothing worthwhile to contribute. In addition, this thread would not have been nearly as useful without Turok's valuable thoughts and healthy skepticism to continue the discussion (in a non-threatening way, no less) for the benefit of all.
My hat is off to both of you. Thanks for providing a very stimulating discussion. I wish there was more I could contribute to this discussion from the backtesting point of view, but this is just not one of my strengths.
Thanks again,
-Eric
Quote from Turok:
Hi abogdan, thanks for weighing in.
>Ok, I have 15 minutes. First of all, it is really hard for
>me to follow your code but I'll try to make general
>comments that jump out right away.
Not sure what you mean by "code" since I didn't post any. I'm assuming you mean my formulas.
You detail your share formula and though I didn't just now go through and test it, I have no doubt that you can and did construct one that does the job. I am also confident that I have done the same. I'm unsure if you are saying that mine is wrong, but for the sake of clarity I will walk through an example using mine and someone point it out if I've gone wrong somewhere.
Assumptions: (numbers chosen for ease of use)
1.111% guaranteed price move
$50.00 open value (OpenVal)
1000 initial shares
penny per share commissions
3 cent spread
So...
Profit target = (50 * 0.0111 * 0.9) +/- $50.00
Our ProfitTarg(s) are 50 cents on each side of our OpenVal or $50.50 for longs and $49.50 for shorts.
and...
>ExpectedProf = abs(OpenVal â ProfTarg)
So...
Expected profit = (50.50 - 50.00) times initial shares
Or: Our ExpectedProf is $500 bucks per winning day
Any problems so far?
For the first set of calcs lets assume it's the open and we have no trades yet and thus no cumulative losses.
>Needed Prof = ExpectedProf + CumLoss + 2xCommish
Our NeededProf is $500 + CumLoss (0) + 2xCommish (unknown until shares are set)
We just use the $500 number to start and calc commish later.
Our short and long flip triggers are set 3 cents off center so when our smoothed bid average crossed the upper line (50.03) we lift and offer and go long. With our 3 cent spread our TradeVal is 50.06
>AvailableRange = abs(TradeVal â ProfTarg)
So the AvailableRange is 0.44
>SharesNeeded = NeededProf / AvailableRange
So the SharesNeeded are 1136
Now we must calculate commissions...(as you will see this ends up not quite perfect but very close with just one round of calcs)
1136 * 0.01 = $11.36
Divide the 11.36 by the AvailableRange and you can see that you must purchase 26 more shares to cover the cost of commissions
So SharesNeeded = 1136 + 26 (or 1162)
Using the above assumptions and formulas, my code will purchase 1163 shares @ 50.06 and hope to sell them at 50.50 for a ~$500 profit after commissions.
At each successive flip the code just adds in the losses so far (including commissions) and recalcs the shares.
If there is a flaw there I'll happily correct it.
JB