'Black Swan' author says investors need to be 'vastly more careful' about market risks

Nassim Taleb, author of The Black Swan.
Adam Jeffery | CNBC

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The author of a famous investing book about large risks for markets told CNBC on Friday that both individual and institutional investors should be preparing their portfolios to withstand big swings in economic conditions.

Nassim Taleb, the author of "The Black Swan," said on "Squawk Box" that massive fiscal and monetary stimulus, combined the virus, has created a lot of uncertainty about price stability and the trajectory of the economy.