In 2001, Dalbar, a financial-services research firm, released a study entitled "Quantitative Analysis of Investor Behavior," which concluded that average investors consistently fail to achieve returns that beat or even match the broader market indices. The study found that in the 17-year period to December 2000, the S&P 500 returned an average of 16.29% per year, while the typical equity investor achieved only 5.32% for the same period—a startling 9% difference!2 It also found that during the same period, the average fixed-income investor earned only a 6.08% return per year, while the long-term Government Bond Index reaped 11.83%.
In a 2015 follow-up of the same publication, Dalbar again concluded that average investors fail to achieve market-index returns. It found that "the average equity mutual fund investor underperformed the S&P 500 by a wide margin of 8.19%. The broader market return was more than double the average equity mutual fund investor's return (13.69% vs. 5.50%)."2 Average fixed income mutual fund investors also consistently underperformed—returning 4.81% less than the benchmark bond market index.
Why does this happen? Behavioral finance provides some possible explanations.
Fear of Regret and stock signals
Fear of regret, or simply regret theory, deals with the emotional reaction people experience after realizing they've made an error in judgment. Faced with the prospect of selling a stock, investors become emotionally affected by the price at which they purchased the stock. 3 So, they avoid selling it as a way to avoid the regret of having made a bad investment, as well as the embarrassment of reporting a loss. We all hate to be wrong, don't we?
What investors should really ask themselves when contemplating selling a stock is: "What are the consequences of repeating the same purchase if this security were already liquidated and would I invest in it again?" If the answer is "no," it's time to sell ; otherwise, the result is regret in buying a losing stock and the regret of not selling when it became clear that a poor investment decision was made—and a vicious cycle ensues where avoiding regret leads to more regret.
Regret theory can also hold true for investors when they discover that a stock they had only considered buying has increased in value. Some investors avoid the possibility of feeling this regret by following the conventional wisdom and buying only stocks that everyone else is buying, rationalizing their decision with "everyone else is doing it."
Oddly enough, many people feel much less embarrassed about losing money on a popular stock that half the world owns than about losing money on an unknown or unpopular stock.
stock signals and Mental Accounting Behaviors
Humans have a tendency to place particular events into mental compartments, and the difference between these compartments sometimes impacts our behavior more than the events themselves.
Say, for example, you aim to catch a show at the local theater and tickets are $20 each. When you get there, you realize you've lost a $20 bill. Do you buy a $20 ticket for the show anyway? Behavior finance has found that roughly 88% of people in this situation would do so.4 Now, let's say you paid for the $20 ticket in advance. When you arrive at the door, you realize your ticket is at home. Would you pay $20 to purchase another? Only 40% of respondents would buy another. Notice, however, that in both scenarios, you're out $40: different scenarios, the same amount of money, different mental compartments. Pretty silly, huh?
An investing example of mental accounting is best illustrated by the hesitation to sell an investment that once had monstrous gains and now has a modest gain. During an economic boom and bull market, people get accustomed to healthy, albeit paper, gains. When the market correction deflates investor's net worth, they're more hesitant to sell at the smaller profit margin. They create mental compartments for the gains they once had, causing them to wait for the return of that profitable period.
Prospect Theory and Loss-Aversion
It doesn't take a neurosurgeon to know that people prefer a sure investment return to an uncertain one—we want to get paid for taking on any extra risk. That's pretty reasonable. Here's the strange part. Prospect theory suggests people express a different degree of emotion towards gains than towards losses. Individuals are more stressed by prospective losses than they are happy from equal gains.5
An investment advisor won't necessarily get flooded with calls from her client when she's reported, say, a $500,000 gain in the client's portfolio. But, you can bet that phone will ring when it posts a $500,000 loss! A loss always appears larger than a gain of equal size—when it goes deep into our pockets, the value of money changes.
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