All these "explanations" below are wrong.
     
    When everything fails - read the manual.
     
    This "MarginRequirement" setting is the property of the 
    BROKERAGE ACCOUNT - 
    account margin (not position margin). It decides how 
    much borrowed funds can be used.
    US regulations allow 50% margin ONLY.
    When account margin is set to 50% it allows position sizes 
    of upto 200% of your cash.
    It does NOT involve deposits.
    This is for STOCKS, not for futures.
     
    This is completely different from futures-like margins and 
    other leveraged instruments.
    You should read the manual about futures 
    margins:
     
    
     
    Best regards,
Tomasz Janeczko
amibroker.com
    
      ----- Original Message ----- 
      
      
      Sent: Tuesday, May 01, 2007 1:09 
      PM
      Subject: RE: [amibroker] Re: Account 
      Margin
      
      Hi Bernard, 
       
      try the following.  As I understand position sizing, when you 
      set position size it is setting the actual postion bought, so a $1000 
      deposit on 10 % margin will be a position size of $10000.  It also 
      depends if you meant actual risk per trade or you meant a deposit of $1000 
      per trade (this is also called fixed position size).
       
      For fixed position size, this is simply as follows ( I like to set 
      everything in my code rather than using the tester).  
      
      Capital = 10000; // Initial Capital $10,000
      Margin = 10; // Margin 10 % CFDs
      // Position 
      Sizing
      PercentCapitalpertrade =  10; // ie 
      $1000 out of a $10K account
      PositionSize = Capital * 
      PercentCapitalPerTrade / Margin;
      // Initial 
      Trade Parameters
      SetOption("InitialEquity", Capital );
      SetOption("MarginRequirement", Margin); // CFD trading 
      requiring 10 % margin
       
       
      Alternatively you can just set PositionSize =10000;  // ie 
      $1000 deposit on 10 % margin
       
      For $1000 risk, you need to set the risk according to the stop 
      value.  Check the user manual for this full explanation of 
      this.  
       
      Positionsize = 
      -2*BuyPrice/(StopDelta);
       
      Cheers, Dave
       
       
       
      etc....
       
       
      
        
        
        
        David
Further to my earlier post - if I can't use "positionsize = 
        -10", 
how do I go about saying therefore that I have a starting 
        equity of 
say, $10,000, with purchasing power of $100,000 (account 
        margin of 
10) but I only want to risk $1,000 per 
        trade?
Bernard
--- In amibroker@xxxxxxxxxps.com, 
        "David Smith" <david.smith5@...> 
wrote:
>
> 
        Have you overriden the margin settings in your code & set to 100, 
        
or perhaps
> set PositionSize in code to a fixed value. This 
        would cause this 
to occur.
> 
> 
> -----Original 
        Message-----
> From: amibroker@xxxxxxxxxps.com 
        [mailto:amibroker@xxxxxxxxxps.com] 
        
On Behalf
> Of bernardedmond01
> Sent: Monday, 30 April 
        2007 9:56 PM
> To: amibroker@xxxxxxxxxps.com
> 
        Subject: [amibroker] Account Margin
> 
> 
> 
> 
        Hi All
> Why is that when I change my account margin setting (e.g. 
        from 100 
to 
> 10) it does not change/affect my position size? 
        I have read 
through the 
> manual and searched on here for any 
        clues but I can't find what 
I'm 
> doing wrong. Any 
        ideas?
> 
      Cheers
>