Glossary

Plain-English definitions of the numbers on this site — no finance degree required. For the exact formulas, see the methodology.

The basics

Fund: A single pooled investment (a mutual fund or ETF) that holds many stocks or bonds so you don't have to pick them one by one.
Index fund: A fund that simply tries to match a market index (like the S&P 500 — the 500 largest US companies) instead of trying to beat it. Usually the cheapest way to own the whole market.
Benchmark: The yardstick you measure a fund against. On this site you can pick any benchmark — the S&P 500, a bond index, or even another fund.
Expense ratio: The fund's annual fee, as a % of your money. 0.03% is $3/year per $10,000; 1.00% is $100/year. Lower is better, and it compounds — small differences matter a lot over decades.
Yield: The income (dividends or interest) a fund pays out over a year, as a % of its price. A 3% yield on $10,000 is about $300/year.

Total return: How much you'd have made over a period, counting both price change and reinvested dividends.
Annualized return: That total return expressed as a steady per-year rate, so a 3-year and a 10-year fund can be compared fairly.
Volatility (std dev): How bumpy the ride is. A higher number means bigger swings up and down — not necessarily worse, but harder to stomach.
Max drawdown: The worst peak-to-bottom drop the fund has had — “if I'd bought at the worst time, how far down did it go before recovering?”
Sharpe ratio: Return earned for each unit of bumpiness — a simple “bang for your risk.” Higher is better; above 1 is good.

Correlation: How closely two funds move together, from −1 (opposite) to +1 (identical). Two S&P 500 funds are ~1.0; a bond fund vs stocks is much lower — which is what makes it a diversifier.
Excess return (xRoR): How much more (or less) a fund returned than its benchmark, per year.
Tracking error (TE): How much a fund wanders from its benchmark. Index funds want this tiny; active funds accept more of it to try to outperform.
Information ratio (IR): Excess return divided by tracking error — reward for each unit of “wandering.” It's how pros judge whether an active manager's bets are paying off.

Outlook: Our transparent, forward-leaning rating (Strong → Weak) based mostly on fees, consistency, age and size within a fund's peer group. It is not advice and not a third-party agency rating.
Category rank: Where a fund places among its peers over the period, 1–100 (1 = best).
Style box: A 3×3 grid showing whether a stock fund leans large/mid/small company and value/blend/growth — a quick read of what it actually owns.
Portfolio X-Ray: Looks through all your funds to the underlying companies, so you can see hidden overlap (e.g. you own Apple three times) and your true mix.
Cheaper twin: A near-identical fund that costs less — one click to see if you're overpaying for the same thing.

All analytics here are hypothetical and for information only — not investment advice.