Regularly re-evaluate your investment theses. Stubbornly holding onto an initial belief despite new, contradictory information can lead to significant losses. This framework encourages adaptation by forcing you to re-earn your conviction at regular intervals, preventing belief calcification.

The worst feeling for an investor is not missing a successful deal they didn't understand, but investing against their own judgment in a company that ultimately fails. This emotional cost of violating one's own conviction outweighs the FOMO of passing on a hot deal.

Entrepreneurs often get burned by a failed investment (like a bad ad agency) and become hesitant to invest in that area again. This is a cognitive trap. The first loss was the money spent; the second, more significant loss is the opportunity cost of not trying again with a better strategy.

The "Liking-Loving Tendency" causes investors to identify personally with their holdings. They ignore faults, favor associated things, and distort facts to maintain positive feelings. This emotional attachment leads them to rationalize bad news and hold deteriorating assets for too long, destroying capital.

Gaonkar identifies her biggest error with NVIDIA wasn't selling too early, but failing to re-evaluate and buy back in later. The psychological pain of "sunk cost bias" makes it incredibly difficult to re-enter a position at a higher price, even when the fundamental thesis has improved.

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.

Private equity managers often get psychologically anchored to their purchase price. Instead of cutting losses on a poorly performing asset to redeploy time and capital, they hold on in the vain hope of getting their money back, turning a bad deal into a time-consuming, mediocre one.

The common advice to overcome sunk cost fallacy—"imagine you didn't own this, would you buy it today?"—is ineffective because you cannot truly ignore the reality of ownership. A more robust method is setting pre-commitment contracts or "kill criteria" that force a decision when specific signals are observed.

Once people invest significant time, money, and social identity into a group or ideology, it becomes psychologically costly to admit it's wrong. This 'sunk cost' fallacy creates cognitive dissonance, causing people to double down on their beliefs rather than face the pain of a misguided investment.