You just need the formula to average a list of shares:
let's try averaging 4 times a share:
1. 10@100
2. 20@90
3. 15@80
4. 12@70
here's the way:
1. calculate the total amount for all the shares:
total amount = (10*100)+(20*90)+(15*80)+(12*70)
2. calculate total shares
total shares = 10+20+15+12
3. Now we can calculate the average price:
Average of all the shares = Total amount / total shares
10*100+20*90+15*80+12*70 = 4840 <-total amount
10+20+15+12 = 57 <- total shares
Average = 4840/57 = 84
so, we have 57 shares @ 84 price.
Averaging 3 or 4 times ,is ok,beyond this it won't be having significant
bearing ,if same number of quantity is assumed for all for ADDS.
Add.1 will have 50% impact (100/2) ,add.2 will have 33%(100/3) impact
add.3 will have 25% impact (100/4) etc..,so the impact keeps on
diminishing.
You will find the cumulative gain is coming down (top value in each column).
So you will find add.5 is useless.(No significant gain).So let us confine ourselves with 2 or 3 adds.