Nassim Nicholas Taleb Quotes

Let us use 10,000 fictional investment managers... [O]nce a manager has a single bad year, he is thrown out of the sample. ...[T]oss a coin; heads and the manager will make $10,000 over the year, tails and he will lose $10,000. ...We have, in a fair game, 313 managers who made money five years in a row. ...[I]f we throw one of these ...into the real world we would get ...comments on his remarkable style, his incisive mind... His biographer will dwell on ...a great mind in the making. ...[S]hould he stop performing (...his odds ...have stayed at 50%) they would start ...finding fault with his dissipated lifestyle. They will find something he stopped doing, and attribute his failure... The truth ...he simply ran out of luck.

Optimism, it is said, is predictive of success. ...It can also be predictive of failure. Optimistic people... take more risks as they are overconfident of the about the odds; those who win show up among the rich and famous, others fail and disappear from the analysis.

[B]ecoming more rational, or not feeling the emotions of social slights, is not part of the human race... not with our current biology. There is no solace to be found from reasoning...

The major problem with inference... is that those whose profession it is to derive conclusions from data often fall into the trap faster and more confidently... The more data we have, the more likely we are to drown in it. For common wisdom... is to base... decision making on the following principle: It is very unlikely for someone to perform... well in a consistent fashion without doing something right. ...[I]f someone performed better... in the past then there is a great[er] chance of performing better than the crowd in the future... But... [a] small knowledge of probability can lead to worse results than no knowledge at all.

I try to make money infrequently, as infrequently as possible simply because I believe that rare events are not fairly valued, and that the rarer the event, the more undervalued it will be in price.

I always remind myself that what one observes is at best a combination of variance and returns, not just returns.

I will use statistics and inductive methods to make aggressive bets, but I will not use them to manage my risks and exposure. ...[A]ll the surviving traders I know seem to have done the same. ...[T]hey make sure the cost of being wrong is limited ...they know ...which events would prove their conjecture wrong and allow for it ...They would then terminate their trade. This is called a stop loss ...I find it rarely practiced.

What is easier to remember, a collection of facts glued together, or a story, something that offers a series of logical links? Causality is easier to commit to memory. ...What is induction exactly? ...It is very handy, as the general takes much less room in onel's memory than a collection of particulars. The effect of such compression is the reduction in the degree of detected randomness.

[W]e like to emit logical and rational ideas but we do not enjoy this execution.

Maximizing the probability of winning does not lead to maximizing the expectation from the game when one's strategy may include , i.e., a small chance of a large loss and a large chance of a small win. If you engaged in a Russian Roulette-type strategy... you are likely to show up as the winner in almost all samples—except in the year when you are dead.

Science had shifted, thanks to Bacon, into an emphasis on empirical observation. The problem is that, without a proper method, empirical observations can lead you astray. Hume came to... stress the need for some rigor in the gathering and interpretation of knowledge... epistemology... Hume is the first modern epistemologist... he was an obsessive skeptic and never believed... that a link between two items could be established as being causal.

David Hume posed the issue in the following way (as rephrased in the black swan problem by... John Stuart Mill) No amount of observations of white swans can allow the inference that all swans are white, but the observation of a single black swan is sufficient to refute that conclusion.

Statistics... is all based on... the steady augmentation of the confidence level... [F]or an n times increase in sample size, we increase our knowledge by the square root on n. ...Where statistics ...fails us, is when we have distributions that are not symmetric... If there is a very small probability of finding a red ball in an urn dominated by black ones, then our knowledge about the absence of red balls will increase [even more] slowly. ...On the other hand, our knowledge of the presence of red balls will dramatically improve once one of them is found. This asymmetry in knowledge... is the central philosophical problem for... David Hume and Karl Popper.

[T]here is a category of traders who have inverse rare events, for whom volatility is often the bearer of good news. Those traders lose money frequently, but in small amounts, and make money rarely, but in large amounts. ...crisis hunters. I am happy to be one of them.

[W]e read too much into shallow recent history... but not from history in general [which] teaches us that things that never happened before do happen. ...outside of the narrowly defined time series; the broader the look, the better the lesson.