Think of the benchmark as a highway. Staying on it gets you to the market return with no drama. An active manager takes detours, hoping to arrive sooner. The information ratio measures how many minutes each detour mile actually saves you, and whether the manager is worth the fuel.
In this guide you will learn what the information ratio is, how to calculate it step by step, what a good score looks like, and how to avoid the mistakes that make this metric look better than it is.
89.93% of US large-cap funds underperformed the S&P 500 over 15 years, per the SPIVA Year-End 2025 scorecard.
S&P SPIVA research page: active funds measured against their benchmarks. Captured 10 October 2026.
What Is the Information Ratio?
The information ratio (IR) measures the active return of an investment per unit of tracking error. Active return is the gap between your portfolio return and its benchmark return. Tracking error is the standard deviation of that gap, which tells you how bumpy the gap was along the way.
The formula is short: IR equals the average active return divided by the tracking error. In notation, IR = E[Rp minus Rb] / standard deviation of (Rp minus Rb), where Rp is the portfolio return and Rb is the benchmark return.
It looks like the Sharpe ratio, and the family resemblance is real. The difference is the yardstick. The Sharpe ratio compares you with a risk-free return such as short-term government bills. The information ratio compares you with a risky index such as the S&P 500 or the MSCI World. Sharpe judges absolute results, and the information ratio judges relative results.
Because it needs a benchmark, the information ratio is mainly a tool for judging active strategies: mutual funds, hedge funds, factor tilts, and your own stock picking. If you simply own the index, your information ratio is undefined or close to zero by design.
The information ratio formula: active return divided by tracking error. Captured 10 October 2026.
Why the Information Ratio Matters
Raw outperformance is a poor scoreboard. A fund that beats the index by 3 percentage points a year sounds great until you learn it did so by holding a concentrated, volatile bet that could just as easily have lagged by 8 points. Return alone ignores the road taken.
The information ratio rewards consistency. Two managers can post the same average edge, but the one who delivers it with a narrow, steady gap scores far higher. That matters because you have to stay invested through the bad stretches, and a smooth edge is easier to hold than a violent one.
The evidence for caution is strong. The SPIVA Year-End 2025 scorecard from S&P Dow Jones Indices, with data to 31 December 2025, shows how rarely the edge shows up.
SPIVA Year-End 2025: share of all US large-cap funds that underperformed the S&P 500
Those percentages explain why a skill metric exists at all. If roughly 9 in 10 large-cap funds trail the index over 15 years, the interesting question is how to spot the minority that earns its fee, and the information ratio is one of the sharpest filters. For the broader case for owning the market cheaply, see our guide to index funds.
0.5 is the information ratio typically achieved by top-quartile managers, according to the figure cited in the standard reference literature (Grinold and Kahn).
How to Calculate the Information Ratio Step by Step
You need a periodic return series for your portfolio and for a fair benchmark. Monthly data works well. Aim for at least 36 months, and more if you can get it.
Step 1: Pick the right benchmark
Choose the index the strategy is actually trying to beat. A global equity fund belongs against a global index, a small-cap value fund against a small-cap value index. A mismatched benchmark is the fastest way to produce a flattering number.
Step 2: Compute the active return each period
Subtract the benchmark return from the portfolio return for every month. If your portfolio made 1.6% and the benchmark made 1.4%, the active return that month is 0.2%.
Step 3: Find the average and the tracking error
Take the average of the monthly active returns, then the standard deviation of the same series. Suppose the monthly average is 0.15% and the monthly standard deviation is 1.0%. That gives a monthly IR of 0.15.
Step 4: Annualize it
Multiply the monthly IR by the square root of 12, which is about 3.46. Here, 0.15 times 3.46 gives an annualized IR of roughly 0.52. The same result comes from an annual active return of 1.8% divided by an annual tracking error of about 3.46%.
Step 5: Read it against a scale
Information ratio rules of thumb (annualized)
Treat these bands as guides, not laws. They come from institutional practice and shift with the asset class and the time period you measure.
Real Examples: Reading the Numbers
The next table uses hypothetical funds so the arithmetic is easy to follow. The point is how the ratio changes the ranking, not the funds themselves.
Illustrative fund comparison (not real funds)
Fund B has the biggest headline edge but the lowest score, because it paid for that edge with a very bumpy gap. Fund C barely beats the index, yet it scores highest because its edge is nearly constant. Whether Fund C is truly better depends on its fees, since a 1.2% edge can vanish after costs.
A practical way to use this is to compute the ratio on rolling three-year windows rather than one lump figure. If the rolling value swings from 1.0 to negative, the manager's edge is unstable, and you should treat the average with suspicion. If it stays in a tight positive band, the edge is more likely to be repeatable.
It also helps to compare the ratio against what you could have got for free. A low-cost index fund has a near-zero tracking error and costs very little, so any active fund has to clear a high bar. For a related measure that focuses on losses in a crash rather than tracking risk, read our explainer on the Calmar ratio.
You can also see a real-world version of the idea in the sample portfolio on MoneyFlock's own tracker. As of 25 September 2026, the S&P 500 portfolio showed 15.32% annualized over 10 years against 13.54% for the S&P 500 index benchmark, a gap of 1.78 percentage points. Divide any such gap by its tracking error and you have an information ratio.
4 years is the sample length you need to trust an information ratio of 1.0, and 16 years for an information ratio of 0.5, using a common t-statistic of 2 rule.
Years of data needed for a statistically convincing IR
The math is simple: the t-statistic equals the IR times the square root of the number of years. That table is the most sobering fact about manager selection, because it shows how little a short track record proves.
Common Mistakes When Using the Information Ratio
Mistake 1: Using the wrong benchmark
Pick an easy benchmark and almost any strategy looks skilled. Always ask whether the index matches the strategy's real holdings and style.
Mistake 2: Trusting a short track record
Three good years can produce an impressive ratio from luck alone. As the table above shows, only a long record separates skill from noise.
Mistake 3: Ignoring fees and costs
Published ratios are often calculated on returns before your costs. A strong edge before fees can shrink to nothing after them, especially for funds with high turnover.
Mistake 4: Treating it like the Sharpe ratio
A high information ratio does not mean the portfolio is safe. It only says the portfolio tracks its benchmark closely or beats it consistently. If the benchmark falls 30%, a fund with a great IR can still fall 30%. Pair it with downside measures such as the Sortino ratio and maximum drawdown.
Mistake 5: Chasing a tiny tracking error
A very high IR can come from a fund that is nearly a copy of the index with a small edge. That is not a flaw, but it is a different product from a high-conviction fund, and the two should not be ranked on one number.
MoneyFlock's Sharpe ratio article, the risk-adjusted cousin of the information ratio. Captured 10 October 2026.
Frequently Asked Questions
What is a good information ratio?
A ratio around 0.5 is typically achieved by top-quartile managers, and above 0.75 is excellent. Anything above 1.0 sustained for many years is rare, so check the data for errors first.
What is the difference between the information ratio and the Sharpe ratio?
Sharpe measures return above a risk-free rate per unit of total volatility. The information ratio measures return above a benchmark per unit of tracking error. Use Sharpe for standalone portfolios and the information ratio for active strategies measured against an index.
Can the information ratio be negative?
Yes. A negative value means the portfolio trailed its benchmark on average. The more negative it is, the more consistently it lost.
How does the information ratio relate to alpha?
Alpha is the excess return, and tracking error is the risk of producing it. The information ratio is alpha divided by that risk. Some analysts use a regression-based alpha in the numerator, and that variant is often called the appraisal ratio.
What is the fundamental law of active management?
Grinold and Kahn showed that the expected IR is roughly the skill per decision (the information coefficient) times the square root of the number of independent decisions per year. A skill of 0.05 applied across 100 independent bets a year points to an IR near 0.5.
How many years of data do I need?
Use at least three years of monthly data as a minimum, and treat anything under five years as a rough guide. For a convincing result, look for a decade or more.
Key Takeaways
- The information ratio is active return divided by tracking error, so it rewards a steady edge over a lucky one.
- Around 0.5 is strong, and top-quartile managers typically achieve about that level.
- SPIVA Year-End 2025 shows 89.93% of US large-cap funds trailed the S&P 500 over 15 years, so a real edge is rare.
- Annualize a monthly IR by multiplying by the square root of 12.
- A 0.5 IR needs roughly 16 years of data to be statistically convincing, so short records prove little.
- Always check the benchmark, the fees, and the downside risk before trusting one ratio.
The detour metaphor still applies. The benchmark is the highway, and a manager only earns a place in your portfolio if the detours save more time than they cost. The information ratio is the stopwatch.
What to Watch Next
- Does the next SPIVA scorecard show the 15-year underperformance rate staying near 90%?
- Do your active funds hold an information ratio above 0.25 after fees over a rolling three-year window?
- Does tracking error for your funds rise when markets turn volatile, and is the edge rising with it?
- Is your benchmark still a fair match as your funds drift in style or size?
- Does any manager you follow keep an IR above 0.5 over five or more years?
References
This article is educational and is not investment advice. Past performance does not guarantee future results.