AI Investors Question Megaproject Economics as Markets Dip

Investors began questioning the economics of AI megaprojects in late October, triggering a Nasdaq plunge of 2.9% on the final trading day of the month, though the Dow finished positively. The market shift reflects growing demands for clearer proof of return on AI investment, even as the real economy showed strength with third-quarter GDP expanding at a 3.4% annualized pace. S&P 500 revenues and operating earnings reached new highs, with profit margins near 13.7%, suggesting corporate America remains healthy despite the AI spending concerns.