Index Funds vs. Actively Managed Funds: What 20 Years of Data Shows
Over 20 years, 94% of active U.S. stock funds trailed their index. Here is what the data shows and when active management still makes sense.
If you could bet on a coin flip where heads wins 94% of the time, you would take heads every single time. That is roughly the odds that a low-cost index fund will outperform an actively managed fund over a 20-year period, according to the most comprehensive study of fund performance ever conducted. The data is not ambiguous, it is not a close call, and it has held up across decades, market cycles, and asset classes. Here is what every investor should understand before choosing between the two.
What Is an Index Fund?
An index fund is a mutual fund or exchange-traded fund (ETF) designed to track a specific market index. The most common example is a fund that tracks the S&P 500, which holds the 500 largest U.S. public companies weighted by market capitalization. The fund does not try to pick winners or avoid losers. It simply owns everything in the index in the same proportions.
The first index fund available to individual investors was launched by Vanguard in 1976. It was widely mocked at the time. Competitors called it “un-American” and “a sure path to mediocrity.” Nearly 50 years later, index funds hold more than $13.4 trillion in U.S. assets, and passive strategies officially surpassed active strategies in total assets under management in 2024.
What Is an Actively Managed Fund?
An actively managed fund employs a portfolio manager (or team of managers) who research companies, analyze data, and make buy-and-sell decisions with the goal of outperforming a benchmark index. The fund charges higher fees to pay for that research and expertise.
The pitch is simple: a skilled manager can identify mispriced securities, avoid overvalued ones, and deliver returns that justify the extra cost. The question is whether the data supports that pitch.
What Does the SPIVA Scorecard Say?
The S&P Indices Versus Active (SPIVA) Scorecard, published by S&P Dow Jones Indices, is the gold standard for measuring active fund performance. It has been running since 2002 and controls for survivorship bias, which is the tendency for failed funds to disappear from the data and make the survivors look better than they are.
The year-end 2024 SPIVA results tell a consistent story:
| Category | 1-Year Underperformance | 5-Year | 10-Year |
|---|---|---|---|
| Large-Cap U.S. Equity | 65.2% | 76.3% | 84.3% |
| Mid-Cap U.S. Equity | 62.0% | 80.0% | 77.3% |
| Small-Cap U.S. Equity | 29.7% | 60.4% | 82.2% |
Over the 15-year period ending December 2024, not a single U.S. equity category had a majority of active managers outperforming their benchmark. Stretch it to 20 years, and 94.1% of all domestic equity funds underperformed the S&P 1500 Composite.
The pattern is remarkably stable: the longer you hold, the worse active management’s track record becomes.
Why Do Active Managers Underperform?
Three structural forces work against active managers, and none of them require the managers to be bad at their jobs.
Fees. The average actively managed equity mutual fund charges an expense ratio of 0.57%. The average passive equity mutual fund charges 0.05%. That 0.52 percentage point gap might sound small, but compounded over decades it is enormous. On a $500,000 portfolio earning 8% annually, the fee difference costs approximately $185,000 over 30 years. Put differently, the index fund investor keeps that money. The active fund investor pays it to the fund company.
A concrete comparison: the Vanguard Total Stock Market Index Fund (VTSAX) charges 0.04% per year. That means for every $10,000 invested, you pay $4 annually in fees. The average actively managed large-blend fund charges roughly 0.80%, costing $80 per year on the same $10,000. Over time, that 20-to-1 fee ratio creates a structural headwind that is extremely difficult for stock selection skill to overcome.
Trading costs. Active funds buy and sell securities frequently. Each trade generates bid-ask spreads, market impact costs, and in taxable accounts, capital gains distributions. Index funds trade only when the index itself changes composition, which for the S&P 500 happens roughly 20 to 25 times per year.
The arithmetic of active management. William Sharpe’s 1991 paper “The Arithmetic of Active Management” laid out a mathematical proof that still holds: before fees, the average actively managed dollar must earn exactly the market return, because active and passive investors collectively own the entire market. After fees, the average actively managed dollar must earn less than the market return. This is not an opinion. It is arithmetic.
Can You Just Pick the Good Managers?
This is the natural objection: if 65% of large-cap managers underperform in any given year, that means 35% outperform. Why not just find those 35%?
The problem is persistence. The SPIVA Persistence Scorecard tracks whether top-performing funds stay on top. The results are sobering. Of the large-cap funds that ranked in the top quartile as of December 2020, only about 3% to 4% remained in the top quartile four years later. Most top performers reverted to the mean or worse.
The mid-year 2025 SPIVA data showed a brief improvement for active managers, with “only” 54% of large-cap funds underperforming. But these short-term fluctuations have appeared before and have never changed the long-term trend. As the S&P researchers noted, “active’s brief shine” tends to be followed by “passive’s lasting edge.”
When Might Active Management Make Sense?
The data against active management is overwhelming in aggregate, but there are a few narrow situations where it may add value.
Less efficient markets. Active managers have historically performed better in small-cap and international markets than in large-cap U.S. equities. In the 2024 SPIVA results, only 29.7% of small-cap managers underperformed over one year. The theory is that smaller, less-followed companies have more pricing inefficiencies for skilled analysts to exploit. Even here, though, the advantage fades over longer time horizons.
Tax management. A skilled active manager in a separately managed account (SMA) can harvest losses on individual securities throughout the year, something an index fund cannot do at the individual shareholder level. For high-net-worth investors in high tax brackets, this tax-loss harvesting benefit can sometimes offset the higher fees.
Fixed income. Bond markets have structural features, including dealer markups, less transparency, and more fragmented trading, that may create opportunities for active managers. The SPIVA results for fixed-income funds are less lopsided than for equity funds, though active managers still underperform the majority of the time over 10-year periods.
What Should You Actually Do?
For most investors, the data points toward a straightforward approach: build a core portfolio using low-cost index funds and spend your time on asset allocation and rebalancing rather than chasing fund managers.
A portfolio holding three or four broad index funds, covering U.S. stocks, international stocks, and bonds, captures the return of the global market at a fraction of the cost of active management. The savings on fees alone can add hundreds of thousands of dollars to your retirement over a 30-year career.
If you want a professional to manage your portfolio, look for a fee-only fiduciary advisor who builds portfolios using low-cost index funds and charges a transparent fee for financial planning, tax strategy, and behavioral coaching. That is where human expertise adds the most value, not in trying to beat the S&P 500.
Ferrante Capital LLC is a registered investment adviser. Information presented is for educational purposes only and does not constitute investment advice, a solicitation, or a recommendation to buy or sell any security. All investing involves risk, including the possible loss of principal.
FC and its principals may hold positions in securities or asset classes discussed in this article. This analysis is for educational purposes only and does not constitute a recommendation to buy, sell, or hold any security.
Forward-looking statements reflect Ferrante Capital’s current analysis and involve assumptions and estimates. Actual results may differ materially. Past performance is not indicative of future results.
Please consult a qualified financial professional before making investment decisions.
