Wall Street’s Quant Playbook Is Upended as AI Reorders Market

The week that AI upended Wall Street’s investing playbook didn’t begin with an earnings miss or a Federal Reserve surprise. It began with a thought experiment on Substack.

A dystopian scenario published by little-known research firm Citrini sent shockwaves through markets, imagining a near-future where AI wipes out white-collar jobs so fast that the economy can’t absorb the blow. International Business Machines Corp. plunged the most in 25 years. Software stocks, already battered, hit fresh lows. Nassim Taleb warned of bankruptcies ahead. By Friday, the jitters had spread — with private credit worries, a hotter-than-expected inflation print, and Middle East fears pushing the S&P 500 to its worst month since March.