For example, if we consider the fund "iShares Core U.S. Aggregate Bond ETF (AGG)", I am trying to figure out how the yearly/Monthly returns are being calculated.
I extracted the historical NAV values from the site: https://www.ishares.com/us/products/239458/ishares-core-total-us-bond-market-etf#/, where I click on Download on the top right of the page.
I am trying to reconcile the returns by calculating them from the Historical tab values and matching it with the monthly performance values in the Performance tab.
If we consider the month of October 2003, I calculate the end of month return as shown:
The resulting value is -0.96%, which matches with the return in the Performance tab.
But if we consider the month of November 2003, calculating the return the same way does not match with the performance return in the Performance tab (0.22%).
My question is, how does one calculate the returns of bond funds, taking into account the regular monthly payouts?