Nassim Nicholas Taleb

[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.

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.

The same past data can confirm a theory and its exact opposite! If you survive until tomorrow, it could mean that either a) you are more likely to be immortal or b) that you are closer to death.

I reject a sole time series of the past as an indication of future performance; I need a lot more than data.

[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.

In most disciplines... asymmetry does not matter. ...People in most fields ...do not have problems eliminating extreme values from their sample, when the difference in payoff between different outcomes is not significant ...A professor ...removes the ...s, and takes the average of the remaining ones, without ...being ...unsound. A casual weather forecaster does the same ...So people in finance borrow the technique and ignore infrequent events, not knowing that the effect ...can bankrupt a company.

We tend to use knowledge as therapy.

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.

[E]conomics is a narrative discipline, and explanations are easy to fit retrospectively. (page 257)

The casino is the only human venture I know where the probabilities are known, Gaussian (i.e., bell-curve), and almost computable.

If you want to get an idea of a friend's temperament, ethics, and personal elegance, you need to look at him under the tests of severe circumstances, not under the regular rosy glow of daily life. Can you assess the danger a criminal poses by examining only what he does on an ordinary day? Can we understand health without considering wild diseases and epidemics? Indeed the normal is often irrelevant.

Sometimes market data becomes a simple trap; it shows you the opposite of its nature... [e.g.,] Currencies that exhibit the largest historical stability... are the most prone to crashes.