Alphabet Inc. and Amazon.com, Inc. accounted for about 71% of the dollar increase in S&P 500 blended earnings since July, underscoring how much of the index’s second-quarter profit growth has been concentrated in a handful of mega-cap companies tied to the artificial intelligence boom. FactSet analyst John Butters said the S&P 500’s blended earnings growth for Q2 2026 was 50.4%, the strongest pace since the stimulus-fueled recovery in 2021, but that figure would fall to 32.0% if Alphabet and Amazon were excluded. The dynamic highlights both the strength of AI-related spending in cloud computing and the market’s sensitivity to any shift in sentiment around the AI trade. Alphabet reported $119.80 billion in second-quarter revenue, above estimates of $116.82 billion, with revenue up 24% year over year and Google Cloud growth accelerating 82%, which CEO Sundar Pichai said was driven by demand for AI infrastructure. Amazon posted $200.61 billion in second-quarter revenue, topping the $196.46 billion consensus estimate, while AWS (Amazon’s cloud-computing unit) revenue rose 36.7% year over year, its fastest growth in 18 quarters, and CEO Andy Jassy said its AI and chip businesses each exceeded a $25 billion annualized revenue run rate.