An investment promises safety of principal and an adequate return after thorough analysis; everything else is speculation wearing a suit.
The line matters more than where Graham draws it. Most people who believe they are investing are on the other side of it, and would recognise that immediately if asked to produce the analysis.
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Typed edges. Anything below the line was authored on the other note and derived here.
prerequisite-of →Buy far enough below your estimate of value that being materially wrong about the estimate still leaves you whole.You can only compute a margin against a value you have actually analysed. Skip the analysis and the discount is not a buffer, it is just a lower price.
← contradicted byReal uncertainty is not a casino — dice have known odds, life does not, and models built on games mislead exactly where it matters.
Graham's definition promises safety of principal after thorough analysis. Taleb's claim is that analysis cannot deliver that where the tails are fat, because the assumption that made it look cheap is correlated with the disaster.