To combat the emotional burden of binary sell-or-hold decisions, use the "Go Havsies" method. Instead of selling a full position, sell half. This simple algorithm diversifies potential outcomes—you benefit if it rises and are protected if it falls—which significantly reduces the psychological pain of regret from making the "wrong" choice.
Investors rarely sell a fund for outperforming its benchmark too aggressively, but they should consider it. Research by Vanguard's John Bogle tracked the top 20 funds of each decade and found they almost always became significant underperformers in the following decade, demonstrating the danger of chasing past winners.
To avoid emotional, performance-chasing mistakes, write down your selling criteria in advance and intentionally exclude recent performance from the list. This forces a focus on more rational reasons, such as a broken investment thesis, manager changes, excessive fees, or shifting personal goals, thereby preventing reactionary decisions based on market noise.
Even long-term winning funds will likely underperform their benchmarks in about half of all years. A Vanguard study of funds that beat the market over 15 years found 94% of them still underperformed in at least five of those years. This means selling based on a few years of poor returns is a flawed strategy.
Investors often judge investments over three to five years, a statistically meaningless timeframe. Academic research suggests it requires approximately 64 years of performance data to know with confidence whether an active manager's outperformance is due to genuine skill (alpha) or simply luck, highlighting the folly of short-term evaluation.