Methodical Investment's David Kaiser suggests that the primary benefit of a rules-based system isn't just performance, but the psychological comfort it provides. It establishes a clear process (if X happens, do Y), removing emotional decision-making and making strategy easier to communicate, especially during volatile periods.
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To avoid making emotionally-driven changes after a losing streak—which Cliff Asness calls his "only negative five sharp ratio strategy"—AQR delays implementing major model adjustments for six months. This forced cooling-off period ensures decisions are based on rigorous research, not recent performance.
Combat indecision and emotional attachment by pre-committing to sell an investment if it fails to meet a specific metric (the state) by a specific deadline (the date). This creates a pre-commitment contract that closes long feedback loops and prevents complacency with underperforming assets.
Smaller initial positions can generate better returns because investors are less emotionally attached. This distance allows the investment thesis the time it needs to mature without being derailed by over-analysis of every minor news event or price fluctuation.
Post-mortems of bad investments reveal the cause is never a calculation error but always a psychological bias or emotional trap. Sequoia catalogs ~40 of these, including failing to separate the emotional 'thrill of the chase' from the clinical, objective assessment required for sound decision-making.
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.
Drawing on a religious analogy, David Kaiser explains that striving for a "perfect" portfolio is a fool's errand. Instead, his rules-based approach is built on the idea of being human and fallible ("missing the mark"). The goal is a good, robust portfolio that can withstand errors, rather than a fragile, optimized-for-perfection one.
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.
To avoid emotional decision-making, especially with losing positions, write down the specific criteria for any investment. Then, backtest those rules against historical data. This replaces emotional struggle with a systematic, data-driven process.
David Kaiser clarifies that "not adapting" refers to the core investment rules, not the portfolio itself. The rules (the "how") remain consistent, but applying them to a changing market naturally results in an evolving portfolio (the "what"). This avoids chasing trends while still adapting to market conditions.
To combat emotional decision-making, Eddie Elfenbein’s strategy mandates replacing exactly five of 25 stocks each year. This rigid structure forces patience and prevents impulsive trades, even when he feels tempted to sell a poorly performing stock. This system prioritizes long-term strategy over short-term reactions.
