Technology giants spend hundreds of billions of dollars on AI, financed with debt. Equity valuations continue to rise, with optimism over technology earnings propelling the S&P 500 and Nasdaq 100 indexes to record highs this week. The only question now is who survives when the bubble bursts and how much of the real economy it takes down with it. Everyone from Big Tech to Wall Street is gambling on AI like it’s a sure thing, but the cracks are already showing. Nearly every major company pouring billions into generative AI still hasn’t seen a real return. The experts say that...