Hmmm... I first tried as xls but the BB wouldn't let me use that file type...

How do you mean plain text? The idea of an Excel file was so you could see the calculations...

I thought it was a list of examples. But anyway, you can upload any file type in a zip archive.

First zip was of a .xlsx. This is a .xls - hope it works better.

Thanks.

Ok, the xls did open and I could look into it. However, your calculations appear too complicated - there is no need for this many parameters. I think you only really need three:

Must_Remain = Capital * sqrt(1 + Profits/Capital)

Available = Capital + Profits - Withdrawals - Must_Remain

Trade_Size = some_factor * (Must_Remain - Withdrawals)

Capital is the initial capital at the first start of the system, Profits and Withdrawals are accumulated since the first start.

Thanks jcl.

The issues/clarifications I see:

In the Must_Remain calculation, some Profits must be reduced based on any removals of Capital which have occurred, based on your response to an earlier question. That response would seem to be in conflict with your last statement that "capital is the initial capital ... Anything else is accumulated". In the real world, if I start trading with, for example, $5k, at some point I may need some of that back for other purposes, withdraw it, and adjust M/R appropriately to stay within Test limits. That real world need complicates the calculations.

Re. Available, the calculation I'm using is Available = Account_Balance - Must_Remain, where Account_Balance reflects not only Profits and Withdrawals, but also Capital additions and withdrawals.

I'm also looking at this spreadsheet as a way to track Withdrawals and Capital changes as time goes by, so it needs to be (just )complicated enough to handle all the activities whenever they occur and help me stay within the Square Root Rule.

Re. Trade_Size, why isn't that simply a function of M/R / Capital Required? Why does it change as Withdrawals occur? (Assuming the Square Root Rule hasn't been violated?)

Thanks.

With "Must remain" I mean here the minimum on the account under the assumption that you do not withdraw more than "Available", and that the system automatically reinvests the rest.

BTW, I've indeed forgotten a factor in the formula above - the trade size is not Must_Remain - Withdrawals, but Must_Remain - Withdrawals/sqrt(1+Profits/Capital). Sorry for that. Here's our 'officially recommended' formula for withdrawals and reinvestment:

Balance on account:  C+P-W
Available to withdraw:  C+P-W-C*f
Available to reinvest:  C*f-W/f

where C is your initial capital at the first start of the system, P the total profit so far, W the total withdrawal so far, and f the square root growth factor sqrt(1+P/C).

Thanks jcl.

For the Z strategies & other similar strategies that we code controlled by M/R, how is "the system automatically reinvests the rest" accomplished? Or should we be manually reTesting and updating M/R whenever the strategy is in profit?

The formulas above assume no Capital is added or removed (other than via reinvestment). My attempt is to cover those scenarios (and combinations of them over time) as well. I don't want to beat this horse to death, so if that's out of scope in order to keep the formulas simple for others, so be it. I'll use my best guess & hope I'm not too far wrong!

Thanks.

The reinvestment is the margin that you can set up through the slider. It could be set proportional to the "Available to reinvest" amount above.

Margin = some_factor * (C*f-W/f)

"some_factor" is your initial margin divided by the initial capital.

Removing or adding capital is simply a withdrawal, positive or negative.

Thanks jcl.

To be sure I understand the first paragraph, let's run through a simple scenario:

I start Z1 with $1,000 Capital and M/R set to values that give CR=$1,000. Wonderfully, the account grows to $2,000 ($1,000 Profit).

Now, I withdraw $586 and go have a party in Paris.

But before I leave , I also (manually, not automatically) reTest and change M/R to settings that give $1,414 CR.

Both changes OK & correct?

Re. the 2nd paragraph, true for adding capital, but not true for removing capital, as from a prior answer previous withdrawals are reduced pro-rata according to the ratio of new capital to original capital, correct?

Thanks.

No. Margin ~ C*f - W/f = 1000*1.414 - 586/1.414 = 1000. Thus, better don't change the Margin settings or your party in Paris may be quickly over.