Active vs Passive: What the Evidence Says

The claim, stated fairly

An active fund employs professionals to select investments they believe will outperform, and charges for the effort. A passive fund holds everything in an index at market weights and charges almost nothing. The active pitch is intuitive: surely trained, informed, full-time professionals can beat a mindless list?

The pitch deserves a fair test, and it has received one. Since 2002, S&P Dow Jones Indices has published the SPIVA scorecard (S&P Indices Versus Active), comparing every active fund in a category against its benchmark, twice a year, with dead funds included. Morningstar runs a similar exercise (the Active/Passive Barometer). These are the closest thing investing has to a controlled experiment, and the results have been stable for two decades.

What the scorecards show

Three findings repeat, year after year, across countries and asset classes.

1. Most active funds trail their benchmark, and the failure rate grows with the horizon. In a typical single year, somewhere between half and two-thirds of US large-cap funds trail the S&P 500. Stretch the window to 10 or 15 years and the share of funds that trailed climbs toward 85–90%+. The pattern holds in Europe, in emerging markets, and in most bond categories. Exact percentages move a little each edition; the shape of the result has not changed since the scorecards began. (The chart below shows the Year-End 2025 US large-cap figures.)

2. Winners don't persist. Perhaps most funds fail, but you'll just pick a good one, ideally one with a great record? The persistence scorecards test exactly that: take the top-quartile funds of one period and check where they rank a few years later. The answer is close to what a coin flip would produce, and sometimes worse. A hot streak is mostly luck plus style tailwinds, and both expire. Chasing past winners is the single most natural instinct in fund selection, and the data is merciless about it.

3. The dead are missing from the brochures. Roughly a third of funds in a typical 15-year window don't survive it: they close or merge, almost always after poor results. Any statistic that looks only at surviving funds flatters active management automatically. SPIVA counts the dead, which is one reason its numbers look harsher than fund-industry marketing.

Why this happens: the arithmetic, not a conspiracy

The result feels wrong to many people, so it helps to see that it must be roughly true. William Sharpe laid it out in a short 1991 paper, "The Arithmetic of Active Management," and the logic fits in a paragraph.

The market's return is the weighted average of everyone who holds the market. Passive investors, by construction, earn that average, minus tiny fees. Active investors, as a group, therefore also hold the market and also earn the average, minus their much larger fees and trading costs. Before costs, active management is a zero-sum game against other active managers: every trade that beats the market has a counterparty who lagged it. After costs, it is a negative-sum game. The average active fund does not underperform because managers are foolish. It underperforms because the group cannot beat itself, and it charges more to try.

Add the modern twist, sometimes called the paradox of skill: professional managers today are better trained and better equipped than ever, and that is exactly the problem. When nearly everyone at the table is skilled, prices already reflect what skill can find, and the remaining differences in results are increasingly luck. Skill has never been higher; the edge from skill has rarely been lower.

The honest counterarguments

Our standards require the other side of the debate, stated properly rather than knocked down cheaply.

• "Gross of fees, managers do show skill." True, and academically supported (Berk and Green's work is the standard reference): many managers generate gross value, but fees and fund size absorb it, so little reaches the investor. This is a real defense of managers as professionals. It is not a defense of buying their funds at retail fees, which is the only decision you face.
• "Active works better in inefficient markets." Small caps, emerging markets and parts of the bond market are less picked-over, and single-year scorecards there sometimes look better for active funds. Over 10+ years, however, the majority still trail in nearly every SPIVA category, partly because funds in exotic markets also charge exotic fees.
• "Someone has to set prices." Correct, and important: if literally everyone indexed, markets would stop discovering prices, and active management would become profitable again, pulling money back in. This self-correcting balance is a genuine open research question, and we give it a full chapter (84). It is an argument about the system, though, not about whether your savings should pay 1.5% a year.
• "I only need to find one great manager." A few certified greats exist. The problem is identifying them in advance: the persistence data says past rank barely helps, and by the time greatness is obvious, the fund is huge, expensive, or closed. You are not choosing between "index fund" and "young Warren Buffett." You are choosing between an index fund and the average fund your bank sells.

What this means for you, practically

This book's conclusion is not "active management is evil." It is narrower and more useful.

1. Make cheap, broad index exposure your default, because that is the bet the evidence pays. This is the core in the core-satellite framework (Chapter 59).
2. If you want active bets, structure them as satellites: sized so that being wrong doesn't change your life, chosen because you understand the specific edge claimed, and reviewed against a benchmark you wrote down in advance.
3. Judge any active fee as a hurdle. A fund charging 1.5% more than an index fund must beat the market by 1.5% every year, forever, just to tie. Fifteen years of scorecards say almost nobody clears that bar, and you cannot identify the exceptions early.

A worked example

Two neighbors invest €10,000 in 2010-style conditions and hold for 15 years while the market returns 8% per year.

• Index route at 0.10%: about €31,300.
• Average active route at 1.6%, matching the market before fees: about €25,300.
• The lucky active route, a fund that genuinely beats by 1% per year after starting fees of 1.6%: about €29,000, still behind the index route.

The third line is the one worth staring at: even a genuinely above-average manager can leave you behind the index once fees are paid. Skill has to be large, persistent and cheap to be worth buying, and that combination is what the scorecards show to be rare.