Benchmark and tracking error

A benchmark is a reference index a fund compares itself to — a stand-in for the slice of the market the fund operates in. Tracking error measures how much the fund’s returns diverge from that benchmark over time. The two go together: the benchmark is the yardstick, and tracking error is how far the fund strays from it.

What a benchmark is

Every scheme states a benchmark in its documents — a published index representing the kind of securities it invests in. It exists so the fund’s results can be read in context rather than in isolation: a return means something different against a benchmark that rose a lot than against one that fell. Regulation requires a scheme to declare a benchmark that genuinely reflects what it does.

What tracking error is

Tracking error captures how closely a fund’s returns follow its benchmark’s. If the fund moved almost exactly with the benchmark, its tracking error is small; if it often moved quite differently, its tracking error is larger. It is a measure of divergence — the size of the gap between fund and benchmark — not a measure of whether the fund did better or worse.

Passive and active funds treat it differently

What divergence means depends on what the fund is trying to do. A passive fund is trying to copy its index, so staying close to it is the entire job and small tracking error is what it is aiming for. An active fund is trying to differ from its benchmark in the hope of beating it, so some divergence is inherent to the approach — a manager who never diverged would just be an expensive index fund. Same number, opposite meaning.

What the figures describe

Together, the benchmark and tracking error let you see whether a fund behaved like the market it is measured against or went its own way. That is a factual description of how it moved relative to a reference — useful context for understanding a fund’s character, especially when read next to its volatility.

What they do not tell you

Neither figure is a verdict. Tracking error tells you the size of the gap, not whether the gap worked out in the fund’s favour, and the right amount of divergence depends entirely on whether you wanted a fund that tracks or one that tries to differ. Both are drawn from the past, so they describe how a fund behaved, not how it will. Read them as context about a fund’s behaviour, not as a score.