NISM-Series-V-A: Mutual Fund Distributors · Risk, Return and Performance of Funds

Benchmarking and Tracking Error for NISM Mutual Fund Distributors

Updated 11 October 2026 · Fact-checked

A benchmark is an index used to judge a fund's performance. Compare like with like: use a Total Return Index (TRI), which includes dividends. Tracking difference is the fund's return minus the index return. Tracking error is the standard deviation of that difference over time. Both matter mainly for index funds and ETFs.

Understand Benchmarking and Tracking Error

A fund's return alone tells you little. A 12% return looks good, but not if the market gave 18%. A benchmark is a reference index that the scheme's mandate is measured against. An equity large-cap fund may use the Nifty 100, a debt fund may use a bond index. The benchmark must match the fund's category, holdings and style.

Indices come in two forms. A Price Return Index (PRI) tracks only the change in share prices. A Total Return Index (TRI) assumes dividends and other income are reinvested in the index. A fund's NAV reflects dividends received by the fund, so the fair comparison is against the TRI. SEBI requires schemes to benchmark their performance against the TRI. Comparing a fund with a PRI makes the fund look better than it really is.

Index funds and ETFs aim to copy the index, not beat it. They still lag it slightly because of expenses, cash held for redemptions, dividend timing and transaction costs. Tracking difference is the gap in returns between the fund and its index over a period. It is usually negative, roughly in line with the expense ratio.

Tracking error measures how consistent that gap is. It is the standard deviation of the daily, weekly or monthly differences between fund and index returns. A low tracking error means the fund follows the index closely. A fund can have a small tracking difference but a high tracking error if the gap swings up and down.

For active funds, you compare returns against the benchmark over several periods. Outperformance (positive difference) is what the fund manager is paid to deliver.

Key formulas to remember

Tracking difference: Tracking difference = Fund return − Index (TRI) return; Measured over the same period. Usually negative for index funds, close to the expense ratio.
Tracking error: Tracking error = Standard deviation of (Fund return − Index return) over the periods; Measures consistency of tracking, not the size of the average gap. Lower is better for index funds.
Excess return over benchmark: Excess return = Fund return − Benchmark return; For active funds, positive means outperformance. Use TRI as the benchmark.
Benchmark rule: Compare fund NAV return (dividends included) with TRI, not PRI; TRI includes reinvested dividends, so it is the like-for-like comparison.

How to solve Benchmarking and Tracking Error questions

Use this method for any benchmarking or tracking question.

1Identify what is asked: benchmark choice, tracking difference, tracking error, or interpretation.
2If a benchmark must be chosen, match it to the scheme's category, market cap, style and asset class.
3Check the index type. For performance comparison, pick the TRI over the PRI.
4Make sure fund and index returns cover the same period and use the same basis (both annual, or both CAGR).
5For tracking difference, subtract: fund return minus index return. Keep the sign.
6For tracking error, remember it is a standard deviation of the differences, so it is never negative.
7Interpret: a lower tracking error means closer tracking; positive excess return for an active fund means outperformance.
8Check the options for the trap: PRI, wrong index, or mixing up difference with error.

Quickest way: Three-second check for tracking questions

When to use it: When the question is a definition or an interpretation, not a calculation.

Say 'difference = gap in returns; error = variation of the gap'.
Say 'TRI for comparison, because dividends are included'.
Say 'index funds want low tracking error; active funds want positive excess return'.
Pick the option that matches, and drop options that reverse these ideas.

Common mistakes in Benchmarking and Tracking Error

Using a Price Return Index to judge a fund
Headline index levels such as the Nifty 50 are usually quoted as price indices.
Fix: Remember the fund earns dividends, so compare against the TRI.
Treating tracking error and tracking difference as the same thing
Both measure how far a fund strays from its index.
Fix: Difference is a simple return gap. Error is the standard deviation of the gap over time.
Thinking a negative tracking difference means a bad fund
Students assume any shortfall is a failure.
Fix: An index fund cannot avoid costs, so a small negative gap near its expense ratio is normal.
Applying tracking error to judge active funds the same way
The term is used loosely across all funds.
Fix: Tracking error is mainly a quality measure for index funds and ETFs. Active funds are judged on excess return and risk-adjusted return.
Choosing a benchmark by popularity
The Nifty 50 or Sensex is the familiar default.
Fix: Choose the index that mirrors the scheme's universe, such as a mid-cap index for a mid-cap fund.
Comparing returns over different periods
Fund and index figures come from different tables.
Fix: Align start date, end date and the return basis before subtracting.

Worked examples

Example 1

An index fund returned 11.6% in a year. Its benchmark TRI returned 12.0% and the benchmark PRI returned 10.2%. What is the tracking difference?

Show the solution

The correct comparison is with the TRI, not the PRI.
Tracking difference = Fund return − TRI return.
= 11.6% − 12.0% = −0.4%.

Answer: Tracking difference is −0.4 percentage points; the fund lagged its TRI by 0.4%.

Example 2

Which statement about tracking error is correct? (A) It is the average difference between fund and index return. (B) It is the standard deviation of the differences between fund and index returns. (C) It is the fund's expense ratio. (D) It is always positive for an active fund that beats its index.

Show the solution

Option A describes something like average tracking difference, not error.
Option C is a cost figure, not a risk measure of tracking.
Option D confuses outperformance with tracking error; error is about variation, not direction.
Option B matches the definition.

Answer: B

Exam tips

Whenever you see 'benchmark' and 'dividends' together, think TRI.
Read carefully whether the question says 'difference' or 'error'; options often swap them.
Remember a lower tracking error is better for an index fund, and it is a standard deviation.
For calculations, keep the sign of the tracking difference; options often differ only by sign.
Expect a scenario asking which benchmark suits a given scheme category; match asset class and market cap.

Practice questions from Risk, Return and Performance of Funds

Benchmarking and Tracking Error in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Benchmarking and Tracking Error: frequently asked questions

What is tracking error in mutual funds?

Tracking error is the standard deviation of the differences between a fund's returns and its index returns over a period. It shows how consistently an index fund follows its index. Lower is better.

What is the difference between tracking error and tracking difference?

Tracking difference is the gap in returns between the fund and its index over a period. Tracking error is the standard deviation of those gaps over time. One is a return gap, the other is a measure of its variability.

Why is TRI used as a benchmark instead of PRI?

A TRI assumes dividends are reinvested, so it captures the full return of the index. A fund's NAV also benefits from dividends it receives. TRI therefore gives a fair like-for-like comparison.

How do I compare a mutual fund with its benchmark?

Pick a benchmark that matches the scheme's category and use its TRI. Compare returns over the same periods and on the same basis. The fund's excess return over the benchmark shows outperformance or underperformance.