🚨 Nearly HALF the S&P 500 is riding the AI trade. A reported basket of 41 AI-linked stocks now represents 49% of the index, drawing comparisons to railroad dominance in the 1880s. History deserves your attention: 🚂 Railroads transformed America. But construction outpaced demand, investment returns deteriorated, and financial panics followed. 💻 The internet transformed the world. Cisco still plunged nearly 90% from its 2000 peak to its 2002 low. The technology can deliver while shareholders get crushed by the price they paid. For $NVDA $MSFT $AMZN $GOOGL $META, watch whether AI revenue and cash flow justify the infrastructure spending. My outlook: If monetization disappoints and spending slows, suppliers could face an amplified hit as earnings estimates AND valuation multiples fall.