Real monthly closes · pick a monthly amount and a start date
The same total put in as a single lump sum on the first contribution date would be worth ¥4,189.58 today, against ¥3,797.72 for spreading it out monthly.
The same fixed amount is bought at every monthly closing price from your start date to the most recent close — no market timing, no skipped months. Units are fractional, so no rounding is applied, and the annualised figure treats the contributions as one lump sum at their dollar-weighted average age, which is an approximation rather than a true internal rate of return.
Price return only — dividends, interest, fees, spreads and taxes are excluded, and past performance says nothing about future returns. Where an asset trades in a currency other than the US dollar, the result is shown in that currency, so the number does not include any exchange-rate move.