Information Ratio

Why information ratio matters

Two managers can deliver the same excess return with very different consistency. The information ratio rewards a manager whose active decisions produced steadier benchmark-relative results. Asset owners use it to compare active mandates, set realistic return objectives, allocate tracking-error budgets, and judge whether fees are supported by repeatable value. It is particularly relevant when the mandate is explicitly benchmark-relative rather than focused on absolute preservation.

How it is applied

Calculate portfolio return minus benchmark return for each observation, find the arithmetic mean of those active returns, and divide by their standard deviation. Monthly estimates are commonly annualized by multiplying the mean by 12 and tracking error by the square root of 12, or equivalently scaling the monthly ratio by the square root of 12. Methods, benchmark, fees, frequency, currency, and sample dates must align.

Formula

Portfolio example

Manager A outperforms by 2% annually with 4% tracking error, producing an information ratio of 0.50. Manager B outperforms by 3% with 9% tracking error, producing about 0.33. Manager A used active risk more efficiently under this measure, although Manager B delivered more excess return. The preferred mandate depends on the investor’s risk budget, confidence, fees, and diversification with other managers.

How to interpret it

A positive ratio indicates positive average active return; a negative ratio indicates underperformance. Higher is generally better, but estimates are noisy and no universal threshold proves skill. The numerator should be meaningful after fees, and the denominator should reflect the intended benchmark. A high ratio with very low tracking error can still represent economically trivial value, while a concentrated strategy may require a long horizon before its process can be judged.

Limitations and common misconceptions

The ratio assumes tracking error is an adequate measure of risk and treats upside and downside active variation equally. It can be inflated by stale pricing, short samples, benchmark mismatch, or hidden tail exposure. Results depend heavily on the period and may not persist. Comparing unrelated mandates is misleading. Investors should examine attribution, drawdown, capacity, liquidity, statistical confidence, and the economic source of active return.