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.

Despite the common focus on bottom-up fundamental analysis, statistical evidence shows two-thirds of an investment manager's relative performance is determined by macro factors, such as whether growth or value stocks are in favor. Ignoring top-down signals like Fed policy is a significant mistake, as it means overlooking the largest driver of returns.

Instead of fighting or fearing market downturns, a superior strategy is to consciously "surrender" to their inevitability. This philosophical acceptance frees you from the draining, low-value work of predicting the unpredictable (recessions, crashes) and allows you to focus on owning resilient businesses for the long term.

While long-term focus is a virtue, investment managers at WCM warn it can become an excuse for inaction. During periods of significant market change, blindly "sticking to your knitting" is a liability. Recognizing when to sensibly adapt versus when to stay the course is a critical and nuanced skill.

Instead of predicting specific companies, identify irreversible macro-trends, or "directional arrows of progress." Examples include the move towards higher energy density (carbohydrates to uranium) or more compact data storage (spinning drives to flash). Investing along these inevitable paths is a powerful strategy.

The modern market is driven by short-term incentives, with hedge funds and pod shops trading based on quarterly estimates. This creates volatility and mispricing. An investor who can withstand short-term underperformance and maintain a multi-year view can exploit these structural inefficiencies.

Long-term economic predictions are largely useless for trading because market dynamics are short-term. The real value lies in daily or weekly portfolio adjustments and risk management, which are uncorrelated with year-long forecasts.

Absolute truths are rare in complex systems like markets. A more pragmatic approach is to find guiding principles—like "buy assets for less than they're worth"—that are generally effective over the long term, even if they underperform in specific periods. This framework balances conviction with flexibility.

John Bogle's wisdom holds that the optimal investment strategy isn't based on historical performance but on what deeply resonates with your core beliefs. This ensures you'll stick with it during inevitable downturns, preventing the performance-destroying behavior of return chasing.