Index funds that track the Nifty 50 or Sensex are popular among salaried Indians for their low cost and market‑wide exposure. 5%, they promise returns that mirror the benchmark without the need to pick individual stocks. In practice, two funds following the same index can perform differently. The crucial measures are persistent tracking difference – the average gap between the fund’s net asset value and the index – and tracking error, which gauges how much that gap fluctuates.
A high persistent difference means the fund consistently lags, while a large tracking error signals unpredictable short‑term drift. Advisors warn against switching funds merely for recent outperformance or the lowest expense ratio. Instead, investors should compare long‑term tracking difference, ensure a low tracking error, and confirm that the fund’s holdings closely match the index. Frequent deviations often hide hidden costs such as higher turnover or cash drag.
For a typical retail investor, these gaps matter over a decade. 2% persistent tracking difference can shave off several percentage points of compounded returns. Reviewing the four checks – tracking difference, tracking error, expense ratio and portfolio fidelity – helps keep the investment aligned with the intended market performance.