The behaviour gap: what investors actually earn versus what their funds return
DALBAR has tracked the difference between what mutual funds return and what the investors inside those funds actually earn since 1994, using fund inflows and outflows to reconstruct real investor behaviour rather than assuming a hypothetical buy-and-hold investor. The gap this produces is called the behaviour gap, and it exists because investors do not hold funds passively. They buy after a rally and sell after a fall, and the sequencing of those decisions destroys value that the fund itself never lost.
The scale of the gap varies sharply by year, and the range tells its own story. In 2024, a year in which the S&P 500 returned 25.02%, the average equity fund investor earned 16.54%, an 848 basis point shortfall and the second-largest gap of the past decade. In 2025, the gap narrowed to just 0.72%, the third-smallest gap since DALBAR's records began in 1985 and the smallest since 2012. Investor behaviour did not structurally improve between those two years. Markets were calmer in 2025, and the gap is a direct measure of how much emotional trading investors did during the period in question. Over the 20 years to the end of 2024, the average equity investor earned 9.24% annualised against the S&P 500's 10.35%, a gap that looks modest year to year and compounds into a very large sum of money over two decades.
The mechanism behind this does not require any special weakness on the part of any individual investor. Loss aversion means a fall in portfolio value registers, psychologically, as roughly twice as painful as an equivalent gain feels good. Recency bias means a market that has just fallen feels more likely to keep falling, and a market that has just risen feels safe to buy into, even though neither instinct has predictive value. These are standard features of how human brains process risk, and they operate on financially literate, intelligent people exactly as they operate on anyone else, which is why the DALBAR gap has persisted across more than 30 years of published data and a huge range of investor types.
The evidence above shows that professional managers, working full time with institutional resources, mostly cannot beat a simple index, and that individual investors, acting on instinct, cost themselves a well-documented, measurable amount most years. Intervention in a portfolio has been shown, repeatedly and across decades of independent data, to be more likely to damage an outcome than improve it. The harder question, given how clear that evidence is, is why intervening remains so difficult to resist. The honest answer is that this has always been a discipline problem rather than a knowledge problem, and discipline under pressure is what a proper financial plan, agreed before the pressure arrives, is built to supply.
Worked examples: what actually happened to someone who stayed invested
Numbers in the abstract can be harder to internalise than a specific story with a start and end date. Several of the worst entry points in modern market history make the case concretely.
An investor who bought at the market peak in October 2007, immediately before the global financial crisis, watched the S&P 500 fall 57% to its trough in March 2009, the deepest drawdown in the US market since the Great Depression. On a nominal price basis, that investor did not see the index recover to its October 2007 high until late March 2013, roughly five and a half years later. An investor who sold at or near the March 2009 bottom locked in the loss permanently and needed to correctly time their re-entry to recover any of it. An investor who did nothing was, by 2013, whole again, and every dollar of the market's subsequent multi-decade advance from that low was still ahead of them.
An investor who bought at the peak in January 1973, just before the oil crisis and stagflation produced a 48.2% decline, faced the slowest recovery in modern market history: 69 months, close to six years, before the index reclaimed its previous high on a nominal basis. This is the closest historical parallel to a true worst-case outcome for a long-term investor. Even here, the investor who held through the full 69 months was restored to their starting position and then participated fully in the strong bull market that followed through the rest of the 1970s and into the 1980s.
Black Monday, October 1987, illustrates how misleading a single headline can be. The Dow fell 22.6% in one session, still the largest one-day percentage decline on record, and the S&P 500 declined 33.5% peak to trough. Reaching a new high took 20 months, a slower recovery than the scale of the crash alone would suggest, because the initial fall itself took only three months. An investor watching the news that October had no way to know, from the size of the daily headline, whether they were looking at the start of a multi-year collapse or a sharp correction that would fully recover within two years, which is what it turned out to be.
An investor who was fully invested through the COVID crash of February and March 2020, the fastest bear market in modern history at a 33.9% decline in 33 calendar days, saw the index reclaim its previous high by August 2020, roughly five months later, the quickest recovery of any major drawdown on record. Someone who sold in the panic of late March 2020 missed one of the sharpest rallies in market history in the process of trying to avoid further losses.
The pattern across all four periods, separated by nearly fifty years and entirely different causes, holds. The market fell hard. It eventually recovered. The recovery timeline was never knowable in advance, sometimes five months and sometimes nearly six years, and the only approach that worked in every case without requiring a correct forecast was staying invested throughout.
Why the headlines feel worse than ever, and why that is by design
Every downturn now seems to feel like a uniquely severe crisis, and that feeling is itself data, just not data about markets. Research published in Nature Human Behaviour, testing more than 100,000 real headlines against real reader behaviour on the same underlying stories, found that each additional negative word in a headline increased the click-through rate by 2.3%, while positive words reduced it. Separate research has found that people amplify a story's negativity further when sharing it with others, adding new negative language beyond what the original report contained. This is a straightforward commercial incentive, not a conspiracy: in an attention economy where every outlet is measured by clicks and every platform's algorithm favours whatever keeps people scrolling, negative framing is simply what performs.
The result is a media and social media environment that is structurally biased towards framing ordinary volatility as extraordinary danger, because that framing performs better than an accurate one. Every historical episode above was reported at the time using the same language now used for far smaller and more ordinary market moves: crisis, collapse, unprecedented, historic. Some of those episodes truly were historic. Most ordinary corrections are not, and the volume and tone of coverage rarely draws that distinction in the moment, because the distinction does not generate engagement.
The intensity of a headline measures how well that headline was designed to be clicked. Treating it as a measure of an event's actual significance to a long-term portfolio is exactly the mechanism that produces the behaviour gap described above.