I have the following issue:

I need to calculate the daily income of a financial application over a period based on a percentage of a daily financial index. The problem is that for each day, this index has a different value. For example:

Date     value
Apr-1    0,048089%
Apr-2    0,045442%
Apr-3    0,041886%
and so on...
Apr-31   0,035450%

On April 1, the initial value of the investment was $ 1,000. How much will the total be on April 31st?

Is there a way to get the final value using a single formula?

The way I do today, I need to calculate the day-to-day balance.

  • $\begingroup$ 30 days have September, April, June and November. So by the time April 31st turns up I guess it will have accrued a lot of interest. $\endgroup$ – CashCow Oct 7 '19 at 10:42

if the values are calculated using discrete compounding, you could do the following.

Formula in Excel:


one line in R


A word of warning: if you are using this to compound interest rates other than overnight rates, you are on the wrong track.

Anyway, I will vote to close the question since its too basic.

| improve this answer | |
  • $\begingroup$ so basic you forgot to apply day-count convention / year fraction. $\endgroup$ – CashCow Oct 7 '19 at 10:44

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