TMT shares — tech, communication services, Amazon and Tesla — produced 87% of the S&P 500’s 2026 gain despite making up about 54% of the index, underscoring an unusually narrow rally.
Goldman tied that concentration to earnings: 2027 profit estimates have risen mainly for AI-infrastructure plays and energy, while the rest of the S&P 500 outside AI and energy has seen no uplift this year.
Positioning and price action look stretched, with hedge funds holding 20% of net market exposure in semiconductors and momentum long-short baskets posting one of the most extreme three-month surges on record.
The imbalance is spilling beyond equities as AI capital spending is pegged at $1 trillion next year — about 3% of U.S. GDP — while rising global yields could make financing that buildout more costly.
Goldman also flagged incoming “shadow supply” from giant IPOs: SpaceX at a rumored $1.75 trillion, plus OpenAI and Anthropic near $1 trillion each, could add volatility and further inflate mega-cap valuations.
As AI drives record stock highs and inflation, is the tech sector building a new economy or a bubble set to burst?
The market is split between AI winners and inflation losers. How long can this divergence last before a major correction?
Can the new Fed Chair tame inflation from an oil shock and AI boom without crashing the entire economy?
S&P 500 Hits Record High in May 2026: AI Boom Drives Market Gains Amid Inflation and Sector Divergence
Overview
As of May 2026, the US stock market has reached record highs, driven mainly by a surge in artificial intelligence investment and strong momentum in the semiconductor supply chain. Major companies like Nvidia, TSMC, and Broadcom are leading this growth, reflecting the rapid adoption of AI across businesses and governments. Institutions are pouring trillions into building the infrastructure needed for AI, such as advanced data centers and chips. Despite this impressive rally, persistent inflationary pressures remain a challenge, creating a complex environment where AI-driven gains stand out against broader economic headwinds.