People justify high-risk strategies by retroactively fitting themselves into a successful subgroup (e.g., 'Yes, most investors fail, but *smart* ones succeed, and I am smart'). This is 'hindsight gerrymandering'—using a trait like 'smartness,' which can only be proven after the fact, to create a biased sample and rationalize the risk.
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Jeff Aronson warns that prolonged success breeds dangerous overconfidence. When an investor is on a hot streak and feels they can do no wrong, their perception of risk becomes warped. This psychological shift, where they think "I must be good," is precisely when underlying risk is escalating, not diminishing.
During due diligence, it's crucial to look beyond returns. Top allocators analyze a manager's decision-making process, not just the outcome. They penalize managers who were “right for the wrong reasons” (luck) and give credit to those who were “wrong for the right reasons” (good process, bad luck).
A good outcome does not automatically validate the decision-making process, as luck plays a significant role. Howard Marks stresses the importance of intellectual humility in recognizing that a successful result could have stemmed from wrong reasons or randomness, a crucial distinction for repeatable success.
This "via negativa" approach, inspired by Sun Tzu and Charlie Munger, posits that the easiest way to improve returns is by systematically avoiding common mistakes. Instead of trying to be brilliant, investors should focus on not doing "dumb stuff," as it's easier to identify what leads to failure than what guarantees success.
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.
When evaluating others' success, ask if their strategy would work for most people who adopt it, or if it relied heavily on luck. If a strategy isn't reproducible and leaves many casualties behind, it's not a model to be learned from, regardless of the impressive outlier outcome.
Every investment decision feels uniquely difficult in the present moment due to prevailing uncertainties. This mental model reminds investors that what seems obvious in hindsight (like buying in 2009) was fraught with risk at the time, helping to counter behavioral biases and the illusion of past clarity.
Our brains are wired to find evidence that supports our existing beliefs. To counteract this dangerous bias in investing, actively search for dissenting opinions and information that challenge your thesis. A crucial question to ask is, 'What would need to happen for me to be wrong about this investment?'
The most common financial mistakes happen not from bad advice, but from applying good advice that is mismatched with your individual personality and goals. Finance is an art of self-awareness, not a universal science where one strategy fits all. The optimal path for someone else could be disastrous for you.
Similar to how charisma is often ascribed to leaders only after their organizations succeed, we tend to label people as geniuses after a major achievement. This creates a narrative fallacy where we assume innate genius caused the success, rather than success causing the attribution of genius.
