Nassim Nicholas Taleb[a] (/ˈtɑːləb/; alternatively Nessim or Nissim; born 12 September 1960) is a Lebanese-American essayist, mathematical statistician, former option trader, risk analyst, and aphorist.

[7] He proposes what he has termed "antifragility" in systems; that is, an ability to benefit and grow from a certain class of random events, errors, and volatility,[8][9] as well as "convex tinkering" as a method of scientific discovery, by which he means that decentralized experimentation outperforms directed research.

[27] Taleb reportedly became financially independent after the crash of 1987 from his hedged short Eurodollar position while working as a trader for First Boston.

Taleb's investing strategies continued to be highly successful during the Nasdaq dive in 2000[28] Several consecutive years of low market volatility and less spectacular returns followed, and Empirica closed in 2004.

Tail risk hedging safeguards investors by reaping rewards from rare events, thus Taleb's investment management career has included several jackpots followed by lengthy dry spells.

[35] Taleb also held positions at NYU's Courant Institute of Mathematical Sciences, the University of Massachusetts Amherst, and the London Business School.

Taleb's five volume philosophical essay on uncertainty, titled Incerto, includes Fooled by Randomness (2001), The Black Swan (2007–2010), The Bed of Procrustes (2010), Antifragile (2012), and Skin in the Game (2018).

[15] Taleb's book The Bed of Procrustes summarizes the central problem: "we humans, facing limits of knowledge, and things we do not observe, the unseen and the unknown, resolve the tension by squeezing life and the world into crisp commoditized ideas".

He opposes most economic and grand social science theorizing, which in his view, suffers acutely from the problem of overuse of Plato's theory of forms.

[50] Triana has stated that Taleb might be correct in recommending that retail banks be treated as utilities, i.e. forbidden to take potentially disastrous risks, whereas hedge funds and other less-regulated investment entities need not be subject to similar restrictions.

He argues that predictive models suffer from Platonism, gravitating towards mathematical purity and failing to take certain key ideas into account such as the impossibility of possessing all relevant information; that small unknown variations in the data can have a huge impact; and flawed theories/models based on empirical data and that fail to consider events that have not taken place but could take place.

Discussing the ludic fallacy in The Black Swan, he writes, "The dark side of the moon is harder to see; beaming light on it costs energy.

[54] Taleb has described his main challenge as mapping his ideas of "robustification" and "antifragility", that is, how to live and act in a world we do not understand and build robustness to black swan events.

[55] One of its applications is in his definition of the most effective (that is, least fragile) risk management approach: what he calls the "barbell strategy" which is based on avoiding the middle in favor of linear combination of extremes, across all domains from politics to economics to one's personal life.

For example, an investor might put 80 to 90% of their money in extremely safe instruments, such as treasury bills, with the remainder going into highly risky and diversified speculative bets.

[58] Taleb appeared with Ron Paul[59] and Ralph Nader[60] on their respective shows in support of Skin in the Game, which was dedicated to both men.

[61] After the 2022 invasion of Ukraine, however, Taleb publicly supported an aggressive response against Russia and denounced "naive libertarians, who think I'm like them because they like my books.

"[62] Taleb wrote in Antifragile and in scientific papers[63] that if the statistical structure of habits in modern society differ too greatly from the ancestral environment of humanity, the analysis of consumption should focus less on composition and more on frequency.

Taleb authored a paper with Yaneer Bar-Yam and Joseph Norman called Systemic risk of pandemic via novel pathogens – Coronavirus: A note.

[65] Aaron Brown, a quantitative analyst and adjunct professor, said regarding The Black Swan that "the book reads as if Taleb has never heard of nonparametric methods, data analysis, visualization tools or robust estimation.

"[66] Nonetheless, he calls the book "essential reading" and urges statisticians to overlook the insults to get the "important philosophic and mathematical truths."

Robert Lund, a mathematics professor at Clemson University, writes that in Black Swan, Taleb is "reckless at times and subject to grandiose overstatements; the professional statistician will find the book ubiquitously naive.

"[72] However, Lund acknowledges that "there are many points where I agree with Taleb," and writes that "the book is a must" for anyone "remotely interested in finance and/or philosophical probability."

[74] Taleb's outspoken and directed commentary against parts of the finance industry—e.g., saying at Davos in 2009 that he was "happy" that Lehman Brothers collapsed—was followed by reports of threats and personal attacks.

He has also been critical of the World Economic Forum at Davos, calling it the "International Association of Namedroppers" and stating "they think it's their mission to solve a problem they don't understand.