How to calculate MWRR？

MWRR (Modified Dietz Method Weighted Rate of Return) is a method of calculating investment returns that takes into account the timing and amount of cash flows into and out of an investment. The formula for MWRR is:

MWRR = (1 + HPR)^(365/n) - 1

Where:
HPR = Holding Period Return
n = Number of days in the holding period

To calculate MWRR, follow these steps:

1. Determine the cash flows: Identify the cash inflows and outflows from the investment during the holding period.

2. Calculate the HPR: Calculate the holding period return by dividing the ending value of the investment by the beginning value, subtracting 1, and adding any cash flows during the period.

HPR = (Ending Value + Cash Flows) / Beginning Value - 1

3. Calculate the number of days in the holding period: Determine the number of days between the beginning and ending dates of the investment.

4. Calculate MWRR: Use the formula above to calculate the MWRR.

For example, if an investment had a beginning value of $10,000, an ending value of $12,000, and received $500 in cash flows during a holding period of 90 days, the calculation would be:

HPR = ($12,000 + $500) / $10,000 - 1 = 0.25 or 25%
n = 90 days
MWRR = (1 + 0.25)^(365/90) - 1 = 1.23 or 123%