Information Ratio: Active Return, Tracking Error, and Benchmark-Relative Skill

What is Information Ratio?

The information ratio measures benchmark-relative return per unit of benchmark-relative risk.

A common ex post form is:

1Information Ratio
2=
3Average Active Return
4---------------------
5   Tracking Error

where:

1Active Return = Portfolio Return - Benchmark Return

and Tracking Error is the standard deviation of active returns.

The ratio therefore asks:

1How much average value above the benchmark was earned for each unit of active-return variability?

It is fundamentally a benchmark-relative measure.

A simple information-ratio example

Suppose an active portfolio has:

1Average annual active return: 2.0%
2Annualized tracking error:    4.0%

Then:

1Information Ratio
2= 2.0% / 4.0%
3= 0.50

A higher positive information ratio means more average benchmark-relative return per unit of measured active risk, all else equal.

The number is unitless.

It is not the portfolio's percentage return.

Information ratio and Sharpe ratio answer different questions

The Sharpe Ratio uses excess return above a risk-free reference and total portfolio Volatility.

The information ratio uses active return above a benchmark and tracking error.

The distinction is:

1Sharpe Ratio
2= excess return over risk-free rate / total volatility
3
4Information Ratio
5= active return over benchmark / tracking error

A passive equity index fund can have a strong Sharpe ratio during a good equity market while having an information ratio near zero because it is not trying to outperform its own benchmark.

An active manager can have a positive information ratio even when the overall portfolio Sharpe ratio is weak during a broad market decline.

Benchmark choice is central

There is no meaningful information ratio without an appropriate benchmark.

A manager can look skillful against an easy or mismatched benchmark and weak against a benchmark that better represents the actual opportunity set.

The benchmark should be consistent with the portfolio's mandate and investment process.

CFA Institute's performance-evaluation framework emphasizes that benchmark misspecification can invalidate appraisal conclusions.

A high information ratio relative to a poor benchmark is not persuasive evidence of skill.

Active return is not necessarily alpha

The numerator is typically benchmark-relative return.

Alpha may instead refer to return unexplained by a selected risk model.

If a manager outperforms a broad index simply by maintaining a persistent exposure to a rewarded systematic factor, the active return can be positive and the information ratio can look attractive.

A richer factor model may attribute much of that performance to measured exposure rather than model-based alpha.

Therefore:

1Positive information ratio != proof of model-adjusted alpha

The concepts overlap but are not synonyms.

Tracking error is the denominator

Tracking error measures the volatility of active returns.

A manager whose active return swings widely around the benchmark has high tracking error.

A manager whose active return is steady has low tracking error.

The information ratio rewards consistency in benchmark-relative performance because the same average active return produces a higher ratio when tracking error is lower.

That makes the ratio useful for evaluating how efficiently an active-risk budget was used.

Small tracking error can make the ratio unstable

Suppose a portfolio's measured tracking error is extremely close to zero.

Even a tiny average active return can then create a numerically large information ratio.

But the estimate may be economically fragile.

Small data errors, benchmark timing differences, fees, or one unusual observation can materially change the numerator or denominator.

A very large ratio should therefore be checked for:

• near-zero tracking error;
• short samples;
• stale pricing;
• benchmark construction effects; and
• return-measurement mismatches.

Do not interpret an extreme ratio without inspecting its components.

Ex post and ex ante information ratios differ

An ex post information ratio uses realized active returns and realized tracking error.

An ex ante information ratio uses expected active return and forecast active risk.

The ex ante ratio is a portfolio-construction input based on forecasts.

The ex post ratio is a historical outcome.

They should not be compared as if they were the same measurement.

Forecast expected return can be wrong, and risk models can underestimate or overestimate future tracking error.

Historical information ratio is not proof of persistent skill

A manager can produce a high historical ratio by chance.

The estimate can also reflect:

• a favorable regime;
• a benchmark mismatch;
• systematic factor exposure;
• survivorship bias;
• selection bias;
• understated transaction costs; or
• an unusually short sample.

Manager-skill evaluation requires broader evidence about process, consistency, statistical uncertainty, capacity, implementation, and whether the source of active return is likely to persist.

A historical ratio is one observation, not a verdict.

Return frequency and annualization matter

Information ratios can be calculated from daily, weekly, monthly, or other periodic active returns.

The mean active return and tracking error must be put on compatible scales.

A common monthly approach is:

1Annualized active return ≈ monthly mean active return × 12
2Annualized tracking error ≈ monthly active-return SD × sqrt(12)

The annualized ratio is therefore often related to the monthly ratio by a square-root-of-time convention under simplifying assumptions.

Serial correlation and time-varying risk can make simple scaling imperfect.

Methodology should be documented.

Fees can reduce the information ratio

Active management costs money.

Management fees, transaction costs, market impact, financing, and taxes can reduce active return delivered to investors.

A strategy with positive gross active return can have weak or negative net active return after costs.

If the denominator remains similar while the numerator falls, the information ratio falls.

For investor decisions, net-of-fee and implementation-aware performance is often more relevant than a gross research backtest.

Capacity can affect future information ratio

A strategy that worked well at small scale may become less effective as assets under management grow.

Larger trades can create more market impact.

Crowded signals can decay.

Liquidity constraints can reduce the number of independent opportunities.

The historical information ratio may therefore overstate future scalability.

This is especially important when the active process depends on small or less liquid securities.

Information ratio and the fundamental law

CFA Institute's current active-management curriculum connects information ratio with the fundamental law of active management.

In that framework, expected active-management performance depends conceptually on forecasting skill, breadth of independent decisions, aggressiveness, portfolio constraints, and how efficiently forecasts are transferred into positions.

The framework is useful because it reminds investors that a good information ratio does not emerge from one number in isolation.

Skill must be applied repeatedly and translated into a portfolio under real constraints.

Information ratio does not show absolute loss risk

A portfolio can outperform its benchmark consistently while still losing substantial money.

Suppose the benchmark loses 30% and an active portfolio loses 25%.

The portfolio generated positive active return despite a severe absolute loss.

The information ratio is therefore not a substitute for:

• Volatility;
• Maximum Drawdown;
• Sharpe Ratio; or
• liquidity and leverage analysis.

It evaluates benchmark-relative efficiency, not total investor pain.

Negative information ratios need context

A negative numerator means average active return was below the benchmark.

As with other ratios with a negative numerator, mechanical ranking can become less intuitive.

An investor should inspect:

1average active return
2tracking error
3benchmark suitability
4sample period
5fees

rather than treating a single negative ratio as a complete diagnosis.

How investors should use the information ratio

A disciplined review asks:

1. What benchmark is used?
2. Is the benchmark appropriate and investable?
3. Is the ratio ex post or ex ante?
4. What return frequency and sample period were used?
5. Are active returns gross or net of costs?
6. How was tracking error estimated and annualized?
7. Is the denominator unusually small?
8. Could systematic factor exposures explain the active return?
9. Is the performance stable across subperiods?
10. What do alpha, Sharpe ratio, and maximum drawdown show separately?

Grizzly Bulls' Models research can be evaluated with these benchmark-relative questions without making this page a live information-ratio authority. The Cyclically Adjusted Risk Premium is separate market context, not the benchmark or active-risk denominator used here.

Sources and further reading

• CFA Institute, 2026, Analysis of Active Portfolio Management: https://www.cfainstitute.org/insights/professional-learning/refresher-readings/2026/analysis-active-portfolio-management
• CFA Institute, 2026, Using Multifactor Models: https://www.cfainstitute.org/insights/professional-learning/refresher-readings/2026/using-multifactor-models
• CFA Institute, 2026, Portfolio Performance Evaluation: https://www.cfainstitute.org/insights/professional-learning/refresher-readings/2026/portfolio-performance-evaluation
• CFA Institute Research and Policy Center, Risk-Adjusted Performance Measures: https://rpc.cfainstitute.org/topics/performance-attribution/risk-adjusted-performance

Explore more topics in the Financial Research Encyclopedia.