Why Most Investors Underperform the Market

Here's a number that should bother you: over the 30 years ending in 2023, the S&P 500 returned an average of 10.2% per year. The average equity fund investor earned just 6.8% per year. That gap — 3.4 percentage points annually — doesn't sound like much until you do the math. On a $100,000 portfolio over 30 years, the market would have turned that into $1.8 million. The average investor ended up with about $720,000. Same market, same time period — but more than a million dollars less in wealth. DALBAR, the research firm that publishes this data every year, has found this gap in every single study they've ever done.

The Behavior Gap

The problem isn't intelligence, education, or access to information. The problem is behavior. Investors consistently do two things wrong: they buy high and sell low. Not because they're stupid — because they're human.

When the market is soaring, excitement builds. Headlines celebrate new highs. Your neighbor brags about his gains. You pile in near the top. Then the market drops 20%, fear takes over, and you sell near the bottom to "protect what's left." Then you wait on the sidelines until the market recovers, confirm it's "safe," and buy back in — at higher prices. Repeat this cycle a few times over a career and you've destroyed an enormous amount of wealth.

Carl Richards, a financial planner and New York Times columnist, coined the term "behavior gap" to describe this pattern. He drew it as a simple sketch: a gap between investment returns and investor returns. That gap is almost entirely caused by bad timing driven by emotions.

Other factors compound the problem. Investors chase hot funds, moving money into last year's winners just as performance mean-reverts. They trade too often, racking up fees and taxes. They check their portfolios obsessively, which amplifies emotional reactions. They overweight recent events and ignore long-term data.

Why It Matters for Investors

Understanding this gap is the first step to closing it. You don't need to beat the market — most professionals can't do it consistently either. You just need to stop beating yourself. If you can simply match the market's return by buying a low-cost index fund and holding it through the inevitable downturns, you'll outperform the majority of individual investors and most mutual fund managers.

The math is stark. Over a 40-year career, earning 10% instead of 6.8% on $500 per month means the difference between $2.6 million and $1.1 million. That's $1.5 million you give away — not to fees, not to taxes, but to your own emotional reactions.

Real Example

Consider the 2020 COVID crash. Between February 19 and March 23, 2020, the S&P 500 dropped 34%. Panic was everywhere. Investors pulled $326 billion out of stock mutual funds and ETFs in March and April. But by August 2020 — just five months later — the market had fully recovered. By the end of 2020, the S&P 500 was up 18% for the year. Those who sold in the panic locked in massive losses. Those who stayed put, or better yet added money during the drop, saw extraordinary gains. The market rewarded patience and punished panic, exactly as it always does.

This isn't a one-time event. The same pattern played out in 2008, in 2001, in 1987, and in every single correction before that. The market goes down, humans panic, the market recovers, and the people who sold are left behind.