The one-sentence summary
Antifragile things get stronger when subjected to stress and tension, whereas fragile things break and robust ones simply stay the same.


• This is a monster of a book sub-titled How to Live in a World We Don’t Understand, and should be viewed in conjunction with his others, The Black Swan and Fooled By Randomness.
• He introduces the concept of Antifragile, in which things get stronger when subjected to stress and tension, such as healed bones.
• By contrast, fragile things break, and robust ones simply stay the same, and so do not progress or improve.
• He believes that we should stop squeezing life into commoditised ideas, categories and pre-packaged narratives, and instead embrace the unknown and the fact that there are limits to our knowledge.


• He introduces many new ways of looking at risk and prediction. Examples include:
~ Procrustean bed: retrofitting causes to events. The idea refers to a Greek myth in which Procrustes abducted his ‘guests’ and then fitted them to a bed – cutting their legs off if they were too tall and stretching them if too short.
~ Fragilistas: these people cause fragility by thinking they understand what’s going on, when in fact they don’t.
~ Barbell strategy: very safe at one extreme (most of the portfolio), and very speculative at another (a small but acceptable proportion of risk).
~ Ludic fallacy: mistaking experiments with the real world, the fallacy is to try to make life resemble games by applying crisp rules – it doesn’t work.
~ Turkeys and inverse turkeys: turkeys think everything is fine until they are killed for Christmas, while the inverse fail to see opportunities on the grounds that searching will ‘never find anything’ (a wrong assumption).
~ Green lumber fallacy: mistaking one type of necessary knowledge for another. A successful trader didn’t even know what green lumber was – it is fresh cut and needs to dry. He just thought it was painted green, but still made a fortune trading it, proving that there are some things you don’t need to know.
~ Extremistan: the inordinate impact of a single outlier observation – all the interesting stuff happens at the margin.
~ Iatrogenics: harm done by the healer, such as blood letting by doctors.
~ Agency problem: if the manager of a business decision is not the true owner, they usually get it wrong.
~ Domain Dependency: This is acting one way in a certain environment and differently in another. Neither work.


• The book is over 400 pages of solid narrative – you need to be determined to stick with it.
• You might want a dictionary to hand – the author likes obscure words, and frequently invents his own.