Citigroup has raised its forecast for AI infrastructure spending by tech companies to over $2.8 trillion through 2029, up from a previous estimate of $2.3 trillion, driven by projected hyperscaler expenditures of $490 billion by the end of 2026. This surge is attributed to the booming AI infrastructure sector, which is becoming a significant contributor to U.S. stock market gains. Companies like Nvidia and Oracle are responding by enhancing their capacity and exploring financing options to support their expansion in this rapidly growing market.