Nassim Taleb spent most of his adult life as an option trader.

Judged against Taleb's documented career as of 2012-12-12 (born 1960, so adult life roughly 1978–2012). True if biographical records show he worked as an options trader for more than half of his adult years to that date (roughly 17+ years, e.g. trading from the early/mid-1980s into the 2000s, including running a trading firm). Mostly true if trading occupied about half of his adult life, or he was largely trading-focused with some overlap with academic or writing work. Mixed if trading was a substantial but clearly minority share, roughly a third to a half. Mostly false if he traded options but for well under a third of his adult life, so 'most' overstates it. False if records show he was not an option trader, or only briefly.

Set before the research began.

1. E1 Official Research Biography of Nassim Nicholas Taleb fooledbyrandomness.com (Taleb's own site) Own record

   “He spent 21 years as a derivatives trader and, after closing 650,000 option transactions and examining 200,000 risk reports, he changed careers in 2006-2010 to become a scholar, mathematical researcher and philosophical essayist.”

2. E2 Nassim Nicholas Taleb | StockEducation StockEducation · 13 October 2026

   “His NYU faculty profile dates his career as a derivatives trader from December 1984 to January 2005.”

3. E3 My First Job: Professor and author Nassim Nicholas Taleb was a Wall Street trader The Independent · 13 March 2008

   “For 10 years I worked full-time; I would arrive at seven o'clock and leave at 5.30 or six.”

4. E4 This Is Not a Profile of Nassim Taleb The Chronicle of Higher Education · 17 December 2012

   “He spent the first couple decades of his career as a derivatives trader before turning to scholarship and essay writing in his mid-40s.”

E2, an independent source citing his NYU faculty profile, dates Taleb's derivatives-trading career from December 1984 to January 2005, about 20 years. E4 independently says he spent the first couple of decades of his career as a derivatives trader before turning to scholarship in his mid-40s. E1, his own biography, gives 21 years and refers to option transactions. Against an adult life of roughly 34 years to 2012, about 20 years exceeds the 17+ year threshold the criteria set for true.