Information Ratio

What Is the Information Ratio?

The information ratio is a portfolio performance measure that compares active return with active risk. In plain English, it asks how much excess return a manager or strategy generated for each unit of benchmark-relative volatility. It is especially useful when evaluating active managers, factor strategies, and portfolios judged against a stated benchmark.

The ratio is not about total return alone. A manager who beats the benchmark by taking huge benchmark-relative swings may have a lower information ratio than a manager who adds smaller but steadier excess returns. That is why the measure pairs return with consistency.

Formula

In this formula, R_p is the portfolio return, R_b is the benchmark return, and σ(R_p - R_b) is the tracking error, or the volatility of active returns. Some practitioners use average active return over multiple periods in the numerator, which makes the ratio a summary of excess return consistency through time.

How To Read It

A positive information ratio means the portfolio outperformed the benchmark over the measurement period after accounting for the chosen active-risk measure. A negative ratio means the portfolio lagged. A ratio near zero suggests the manager took active risk without producing much excess return. Higher is generally better, but only if the inputs are measured consistently and the benchmark is fair.

There is no universal magic cutoff. A strong information ratio in one asset class, mandate, or market cycle may not be directly comparable with another. A concentrated small-cap strategy may naturally have higher tracking error than a diversified core bond strategy. The ratio is most useful when comparing managers with similar mandates and benchmarks.

Benchmark Discipline

The information ratio can be misleading if the benchmark is wrong. A global equity manager measured against a domestic large-cap index may look skillful or weak for reasons unrelated to security selection. A bond manager measured against a benchmark with different duration or credit exposure may show active return that is really just a structural risk mismatch.

That is why benchmark selection comes before the calculation. The benchmark should reflect the opportunity set, risk profile, currency, duration, style, and constraints of the actual mandate. Once the benchmark is sound, the information ratio can help show whether active decisions were rewarded.

Example

Suppose a portfolio returned 10% while its benchmark returned 7%, producing a 3% active return. If tracking error was 6%, the information ratio is 0.50. If another manager produced the same 3% active return with 3% tracking error, the information ratio is 1.00. The second manager delivered the same excess return with less benchmark-relative volatility.

This does not automatically make the second manager better for every investor. Fees, taxes, drawdowns, capacity, style drift, liquidity, and the client’s goals still matter. The information ratio is a focused tool for active performance appraisal, not a full manager scorecard.

Annualization also deserves care. Monthly active returns, quarterly active returns, and annual returns can produce different-looking ratios if the numerator and denominator are not scaled consistently. The measure is simple, but sloppy inputs can make a manager look more or less skillful than the record supports.

The Bottom Line

The information ratio helps investors judge whether active risk was compensated. It is strongest when used with a fair benchmark, consistent return data, and a broader review of fees, taxes, risk, and mandate fit.