1. Why Simple Absolute Returns and CAGR Fail for SIPs
When evaluating mutual fund investments, many investors confuse absolute returns or CAGR with their actual portfolio yield. Absolute return simply measures total gains divided by total cost, completely ignoring the duration for which your money was invested.
CAGR assumes a single lump sum deployed at day one. For systematic monthly investments where capital is introduced in staggered tranches over years, applying simple CAGR produces misleading figures.
2. How XIRR Accurately Measures Staggered Cash Flows
XIRR (Extended Internal Rate of Return) assigns a distinct internal compounding rate to every individual SIP payment based on its exact date of debit.
By assigning individual time-weightings to each monthly payment, XIRR reflects the true annualized rate of return earned by your deployed money.
Comparative Analysis Breakdown
| Return Metric | CAGR (Compounded Annual Growth Rate) | XIRR (Extended Internal Rate of Return) |
|---|---|---|
| Cash Flow Input | Single Lump Sum initial payment | Multiple recurring SIP installment dates |
| Timing Sensitivity | Ignores purchase dates | Exact dates and money weighting included |
| Accuracy for Monthly SIPs | Inaccurate (Distorts true yield) | 100% Mathematically Precise Benchmark |