| Title: | Market Investing | 
| Moderator: | 2155::michaud | 
| Created: | Thu Jan 23 1992 | 
| Last Modified: | Thu Jun 05 1997 | 
| Last Successful Update: | Fri Jun 06 1997 | 
| Number of topics: | 1060 | 
| Total number of notes: | 10477 | 
    Something tells me I should know how to do this, but I'm drawing a
    blank.  How do I calculate the periodic return, with a mid-term
    contribution. e.g.
    
    	Begin of period	Balance =	1000
    
    	Mid-term	Contribution =	 250
    
    	End of period	Balance =	1500
    
    
    What's the formula to calculate my periodic return?
| T.R | Title | User | Personal Name | Date | Lines | 
|---|---|---|---|---|---|
| 359.1 | 22.22 % | BROKE::RAM | Wed Jan 20 1993 21:37 | 16 | |
| 
    Let A(i) = i'th investment
    Let p(i) = period of the i'th investment
    Let F = final value of investment
    Then growth in investment G = F - (A(1) + A(2) + ... + A(n))
    where n is the number of investments.
    Then yield Y = G / ( (A(1) * p(1)) + (A(2) * p(2)) + .... + (A(n) * p(n)) )
    In your case A(1) = 1000, p(1) = 1, A(2) = 250, p(2) = 0.5
    So G = 1500 - 1250 = 250,
    and Y = 250 /( 1000 * 1 + 250 * 0.5) = 250/1125 = 0.2222 or 22.22%
     
    
    
 | |||||