Are Too Many People Investing in Index Funds?

Summary

Tim Edwards of S&P Dow Jones Indices discusses evidence on active versus index investing, the scale of index-fund ownership and trading, portfolio concentration, and the cost of waiting for a market downturn.

SPIVA performance data

SPIVA (“S&P Index versus Active”) compares actively managed stock and bond funds with category benchmarks. S&P Dow Jones Indices updates its dashboards every six months across markets.

The latest European report cited covers fund performance through mid-2026:

• Global equity funds: 65% underperformed their benchmark in the first half of 2026.
• U.S. equity funds: 57% underperformed.
• European equity funds: 76% underperformed.
• Emerging-market equity funds: 30% underperformed, meaning 70% outperformed over that period. Edwards linked the result in part to varied market dynamics, including AI-related companies in Korea and Taiwan, and moves in materials and energy tied to geopolitics.

Edwards cautioned that short-term results vary. Over longer periods, underperformance is more common: in the European report’s stock and bond categories, roughly 8–9 out of 10 funds underperformed over 10 years. He described a typical long-term equity figure as 85–90% underperforming, while short-term figures often fall around 55% to 75%.

These results do not mean that no active funds outperform. Edwards said outperformance exists across nearly all markets, but identifying the winners in advance is difficult.

Persistence of fund performance

S&P’s persistence dashboard examines whether past winners continue to win:

• Of 328 European funds in the top quartile at the end of 2021, only four remained top-quartile performers for five consecutive years.

Edwards said performance can reflect luck, cyclical styles such as value or growth, and the difficulty of scaling a successful strategy as it attracts more capital. He also described beating the market as intensely competitive: an edge can be copied or stop working, requiring ongoing research, technology, and resources.

Portfolio construction and market dynamics

• Diversification: Edwards cited research by finance professor Hank Bessembinder, saying a small share of stocks accounts for exceptional long-run returns. Because it is hard to identify those stocks in advance, he argued that broad diversification helps investors participate in potential winners.
• Stocks and bonds have different risks: A stock can lose 100% of its value but has potentially very large upside. Most bonds pay their stated interest and principal, but defaults can cause severe losses. Edwards said concentrated bond portfolios can look better than average if they avoid defaults, while a default can sharply hurt performance.
• Active performance is relative: Edwards distinguished the overall potential for investors to benefit from economic growth from the narrower, zero-sum nature of outperforming the market average: not everyone can be above average.
• Asset allocation is another form of active decision-making: Investors may make choices about stocks versus bonds, inflation-protected bonds, domestic versus international markets, currency exposure, and growth versus defensive investments. Edwards said these choices may be more closely aligned with an investor’s risk tolerance and cash-flow needs than trying to pick funds that will beat their benchmarks. He noted that risk needs can differ substantially by age and circumstance.
• Index funds do not necessarily mean passive behavior: Investors can use index-based ETFs actively—for example, through sector funds or short-term trading. Edwards said the debate is partly about what investors are active in, not simply active versus passive products.

How much of the market is indexed?

Edwards said the share of mutual-fund assets in index funds can be misleading because it excludes other investors and vehicles. He estimated that less than half of the U.S. stock market is indexed to major indices—perhaps one-third to 40%. He said less than 10% of bonds are held in funds, with the rest held directly or through other vehicles.

He also noted that index-tracking products can be heavily traded: an S&P 500 ETF is often among the world’s most-traded securities, and he estimated that about 24 of the 50 most-traded stocks may be index-tracking ETFs.

On trading turnover, Edwards offered these comparisons:

• A directly indexed S&P 500 portfolio might require 5–10% annual turnover as a conservative estimate. In practice, he said actual turnover is often closer to 2–3%, with dividends reinvested.
• Traditional active mutual funds commonly report 50–100% annual turnover.
• On those assumptions, roughly five times as much money would need to be in index strategies as active strategies to produce a comparable amount of trading. Edwards did not expect that ratio to occur, partly because more indexing could create opportunities for active investors.

He emphasized that transactions, rather than ownership alone, set prices, while acknowledging that index investing can influence markets.

Market-cap weighting, free float, and equal weighting

Edwards argued that buying a capitalization-weighted index does not necessarily mean buying a larger proportion of available shares in larger companies: the index generally allocates in proportion to market value and available supply. He stressed the role of free float—shares available to trade—as distinct from shares held by founders or other long-term owners. The S&P 500 and most major indices use free-float market capitalization, he said.

He used SpaceX and Saudi Aramco as examples of companies with relatively small shares available to trade, and discussed concerns that a low float can make a company’s market value appear disproportionately large when a small portion of shares sets the price.

Equal-weighted indices provide a different approach:

• An equal-weighted S&P 500 would allocate 1/500 of the portfolio to each constituent.
• The index generally needs periodic rebalancing—often quarterly—to restore equal weights.
• Edwards said equal-weighted and capitalization-weighted indices can differ by 10–20% in annual performance in some years.
• He estimated equal-weighted indices may have 20–25% annual turnover, compared with the much lower turnover of a capitalization-weighted index. Rebalancing sells relative winners and buys relative losers, creating an anti-momentum effect that may help or hurt.
• Equal weighting may reduce exposure to large-company concentration, but it is an active departure from market-cap weighting. Its relative performance depends on market conditions: Edwards said rising concentration tends to favor capitalization weighting, while falling concentration can favor equal weighting.
• As an example of concentration, a host said the top 10 U.S. stocks represented almost 40% of the market.

Edwards said there is no universal answer on whether investors should use equal weighting. He noted that substantially more money is invested in capitalization-weighted strategies, and that long-term outperformance of market-cap-weighted indices is difficult to achieve.

Waiting for a market decline

Edwards discussed S&P’s “Waiting for a Bear” analysis. A bear market was defined as a decline of 20% from a peak.

• When not already in a bear market, the historical average wait for one was about three years.
• Historically, after an all-time high, the more common outcome was another all-time high.
• The average can conceal long waits: some investors may remain out of the market for 12 years, while prices rise substantially—potentially doubling, tripling, or more.
• Edwards said waiting for a market “sale” had historically been a poor strategy on average, despite the appeal of buying at a lower price.

Assets, instruments, and companies mentioned

No ticker symbols were stated. The discussion mentioned:

• Indices and funds: S&P 500, S&P World, index funds, mutual funds, and ETFs.
• Equities and companies: Nvidia, Apple, IBM, McDonald’s, Amazon, Microsoft, SpaceX, and Saudi Aramco.
• Markets and sectors: U.S., European, and emerging-market equities; semiconductors; AI-related companies; materials; and energy.
• Fixed income and cash: Government bonds, UK 5–7-year government bonds, corporate bonds, inflation-protected bonds, and cash.
• Other instruments: Futures, options, and derivatives linked to indices.
• Other assets: Cryptocurrencies were mentioned briefly by a podcast host, without any specific coin being identified.

Disclosures and cautions

Edwards disclosed that S&P Dow Jones Indices benefits financially when its indices are used as benchmarks, as the basis for investment products, and for futures, options, and other derivatives. He said the firm’s stated role is to provide data rather than prescribe an investment approach.

The subtitles include promotional segments for Vanta and Uswitch. The Uswitch segment advertised solar installations costing £8,000–£10,000 upfront, with claimed average savings of around £1,000 per year. It said a third of customers could recoup costs faster and that some financing arrangements could produce positive cash flow from month one. These are sponsor claims, not investment-performance data.

The provided subtitles contain no explicit “not financial advice” disclaimer. Edwards repeatedly noted that there are no guarantees and avoided giving a universal recommendation on equal weighting.

Presenters and sources

• Guest: Tim Edwards, S&P Dow Jones Indices.
• Presenters: Making Money Podcast hosts; their names are not reliably identifiable from the subtitles.
• Sources discussed: S&P Dow Jones Indices’ SPIVA reports and persistence dashboard; S&P’s “Waiting for a Bear” analysis; and research by Hank Bessembinder. Elroy Dimson was also cited in the hosts’ discussion of equal weighting and stock-market returns.