The answer in plain English

Historical files can contain several plans and options with similar display names. Before computing returns, isolate the intended series and check observations around your start and end dates. A calendar date that is not a business day may not have a fresh valuation for that series.

What to check

  • Verify the full scheme name and its identifier before downloading.
  • Keep a date column and numeric NAV column, with source and retrieval date.
  • Check for duplicate rows, missing observations and unit/name changes.
  • Use XIRR for actual contributions/withdrawals rather than treating every investment as present at the first NAV.

A useful comparison

Spreadsheet fieldPurposeCheck
Scheme/plan/optionSeries identityAvoid mixing similar names
NAV dateObservation timingNot the website retrieval timestamp
NAV valueUnit valuationNumeric format and adjustment history
Cash-flow date/amountPersonal return calculationKeep deposits, withdrawals and ending value distinct

Make the distinction clear

Illustration: a fund’s NAV goes from ₹20 to ₹22, a 10% point-to-point change. Someone who invested only near the end did not earn that entire period’s return. Use the dated cash-flow tool for the personal outcome. A spreadsheet is useful because its assumptions and inputs can be checked; a smooth chart without those details is not stronger evidence.

One final question before acting

Does the figure or document match the exact scheme, plan, option, period and purpose in your question? Keep the source date with the answer. For a real transaction or personal decision, the current scheme documents and your own records take priority over a saved educational example.