An Investing Principles Checklist
Risk – All investment evaluations should begin by measuring risk, especially reputational 
 Incorporate an appropriate margin of safety 
 Avoid dealing with people of questionable character 
 Insist upon proper compensation for risk assumed 
 Always beware of inflation and interest rate exposures 
 Avoid big mistakes; shun permanent capital loss 
Independence – “Only in fairy tales are emperors told they are naked” 
 Objectivity and rationality require independence of thought 
 Remember that just because other people agree or disagree with you doesn’t make you right or wrong – the only thing that matters is the correctness of your analysis and judgment 
 Mimicking the herd invites regression to the mean (merely average performance) 
Preparation – “The only way to win is to work, work, work, work, and hope to have a few insights” 
 Develop into a lifelong self-learner through voracious reading; cultivate curiosity and strive to become a little wiser every day 
 More important than the will to win is the will to prepare 
 Develop fluency in mental models from the major academic disciplines 
 If you want to get smart, the question you have to keep asking is “why, why, why?” 
Intellectual humility – Acknowledging what you don’t know is the dawning of wisdom 
 Stay within a well-defined circle of competence 
 Identify and reconcile disconfirming evidence 
 Resist the craving for false precision, false certainties, etc. 
 Above all, never fool yourself, and remember that you are the easiest person to fool 
“Understanding both the power of compound interest and the difficulty of getting it is the heart and soul of understanding a lot of things.” 
Analytic rigor – Use of the scientific method and effective checklists minimizes errors and omissions 
 Determine value apart from price; progress apart from activity; wealth apart from size 
 It is better to remember the obvious than to grasp the esoteric 
 Be a business analyst, not a market, macroeconomic, or security analyst 
 Consider totality of risk and effect; look always at potential second order and higher level impacts 
 Think forwards and backwards – Invert, always invert 
Allocation – Proper allocation of capital is an investor’s number one job 
 Remember that highest and best use is always measured by the next best use (opportunity cost) 
 Good ideas are rare – when the odds are greatly in your favor, bet (allocate) heavily 
 Don’t “fall in love” with an investment – be situation-dependent and opportunity-driven 
Patience – Resist the natural human bias to act 
 “Compound interest is the eighth wonder of the world” (Einstein); never interrupt it unnecessarily 
 Avoid unnecessary transactional taxes and frictional costs; never take action for its own sake 
 Be alert for the arrival of luck 
 Enjoy the process along with the proceeds, because the process is where you live 
Decisiveness – When proper circumstances present themselves, act with decisiveness and conviction 
 Be fearful when others are greedy, and greedy when others are fearful 
 Opportunity doesn’t come often, so seize it when it comes 
 Opportunity meeting the prepared mind; that’s the game 
Change – Live with change and accept unremovable complexity 
 Recognize and adapt to the true nature of the world around you; don’t expect it to adapt to you 
 Continually challenge and willingly amend your “best-loved ideas” 
 Recognize reality even when you don’t like it – especially when you don’t like it 
Focus – Keep things simple and remember what you set out to do 
 Remember that reputation and integrity are your most valuable assets – and can be lost in a heartbeat 
 Guard against the effects of hubris (arrogance) and boredom 
 Don’t overlook the obvious by drowning in minutiae (the small details) 
 Be careful to exclude unneeded information or slop: “A small leak can sink a great ship” 
 Face your big troubles; don’t sweep them under the rug 
In the end, it comes down to Charlie’s most basic guiding principles, his fundamental philosophy of life: Preparation. Discipline. Patience. Decisiveness.