Topic: Incoherent Entries on Bollinger Bands

Popov,
I have been  having some hard time these last days to understand how EXACTLY  your BB entry works ...
No matter what mode is selected (nothing, add or winner), some incoherent position entries seem to be taken in FSB ... or maybe I don't understand well how the BB UpBand (or DnBand) crossing works.
Would you help me clarify ?
Here-attached is a "self-explanatory" picture ...
Alain
http://s1.postimage.org/1ih2mi.jpg

Re: Incoherent Entries on Bollinger Bands

Alevi,
I cannot reproduce this. Please sent me the following files by email:
- Program config file: \System\config.xml
- Instruments config file: \Systems\instruments.xml
- Data file: \Data\XXXXXXX.csv
- Your strategy file: \Strategies\ SSSSSS.xml

I'm pretty sure we'll fine a rational explanation.

Re: Incoherent Entries on Bollinger Bands

Popov,
I cannot attach files to Email ...
Alain

Re: Incoherent Entries on Bollinger Bands

Popov,
I cannot attach files to the 'Forum Email' function...
I will place those files on to my FTP and send you the address in a PM.
Alain

Re: Incoherent Entries on Bollinger Bands

Files received. Thank you!

Re: Incoherent Entries on Bollinger Bands

Alevi,
The files that I received are different. The strategy is different and the spread / swaps are not zero.

I cannot see anything wrong in the chart. Please, tell me the numbers of bars where the problem is.

Re: Incoherent Entries on Bollinger Bands

Popov,
See this 2 pics.
Alain
http://s3.postimage.org/10sZSi.jpg

Re: Incoherent Entries on Bollinger Bands

Popov,
See this 2 pics.
Alain

http://s2.postimage.org/1Bb0Y0.jpg

Re: Incoherent Entries on Bollinger Bands

Popov,
I have updated the files that you requested on my FTP, just "in case of " ...
   - Program config file: \System\config.xml
   - Instruments config file: \Systems\instruments.xml
   - Data file: \Data\XXXXXXX.csv
   - Your strategy file: \Strategies\ SSSSSS.xml
Alain

Re: Incoherent Entries on Bollinger Bands

Alevi,

The instruments.xml you send me is different:

<instrument>
<symbol>EURUSD</symbol>
<instrumentType>Forex</instrumentType>
<comment>Euro vs US Dollar</comment>
<digits>4</digits>
<contractSize>10000</contractSize>
<spread>3</spread>
<swapType>pips</swapType>
<swapLong>1</swapLong>
<swapShort>-1</swapShort>
...
...

It shows spread 3 pips. But never mind.

Do you take into account that the signals are sent at the previous  BB value.
The check box "Use previous bar value" of BB is marked. That means the entry is at the value of BB from the previous bar. By default this check box is controlled automatically because not all traders are familiar with this subject and any error is vital for the correct backtest.

There are more info about this here http://forexsb.com/library/useprevbarvalue.html

Re: Incoherent Entries on Bollinger Bands

Popov,
Actually, I have updated the files on my FTP and the instruments.xml shows now spread and swaps to zero.
Yes, I took into acct that signals are sent at the previous BB value and by the way the small green 'buy' or 'sell' flags show well this particular point on the chart.
My concern is to understand WHY, on the attached pic, the 3 highlighted bars trigger a buy order whereas they all are well UNDER the UpBand ... and that EVEN the previous bar of each of these three bars is ALSO under the UpBand !!!
To me, it does not make sense that ANY of these bars should trigger a buy order ...
What do you think ?
Thx.
Alain
http://s3.postimage.org/10vBuJ.jpg

Re: Incoherent Entries on Bollinger Bands

Please refer to the info in the right side of the chart. Point the 'cross' over the desired bar.

On the Bollinger Bands details you can see the entry price:  Long position entry price: xxxxxx
This entry price is equal to the Upper BB band from the previous bar (you have to point it): Upper Band: xxxx

Going down on the info (use 'z' key) you'll see the entry point.
Look for:
Type of the transaction: Add
Forming order price: xxxxxx


The "forming order price" is the entry price in your case. This price must be equal to the shown above "Long position entry price" and to the previous BB Upper Band. Take into account that the entry price was properly normalized according to the broker's Digits. In your case the entry price is rounded to the 4th digit. The BB bands on the chart are not normalized and they are plotted with full precision.

Some times you can see difference in the levels of entry and an indicator because of the rounding (the charts uses rounded pixels) especially in over-zoomed charts and when the charts Min - Max prices are near. On mine monitor some times 1 pips difference in the price is more than 5mm on the chart.

Re: Incoherent Entries on Bollinger Bands

Popov,
Thank you ... it is way more clear to me now.
Alain