In the evaluation of passive index funds and Exchange Traded Funds (ETFs), what does 'Tracking Error' measure, and what is the ideal tracking error level for an efficiently managed index fund?

[ A ]It measures the total broker commission paid per year; a tracking error of 100% is ideal.

[ B ]It measures the standard deviation of excess returns of the fund relative to the index it mimics; a lower tracking error (close to zero) indicates superior replication efficiency.[ CORRECT ]

[ C ]It measures the number of unitholders who redeemed units during market holidays.

[ D ]It measures the percentage of corporate bonds downgraded to default status.

Takeaway

Option B is correct: It measures the standard deviation of excess returns of the fund relative to the index it mimics; a lower tracking error (close to zero) indicates superior replication efficiency.

Derivation

An index fund seeks to mirror the exact composition and weightages of a target benchmark index. Tracking Error measures how closely the fund replicates the index returns and is calculated as the annualized standard deviation of the difference in daily returns between the scheme and the benchmark index. For an index fund, the goal is not to beat the market but to achieve a tracking error as close to zero as possible (accounting only for mandatory cash friction and TER drag). This tests index fund evaluation. A common error is believing index funds should have high positive tracking error.

Why the others fail

A — It measures the total broker commission paid per year; a tracking error of 100% is ideal.

Tracking error measures return replication variance, not broker commission, and a high tracking error indicates poor index replication.

C — It measures the number of unitholders who redeemed units during market holidays.

Unitholder transaction volumes on holidays do not determine tracking error standard deviation metrics.

D — It measures the percentage of corporate bonds downgraded to default status.

Tracking error evaluates index tracking replication in passive funds, having no relationship to corporate bond defaults.