S&P 500 Q2 2026 earnings beat records, but stocks fall on AI capex skepticism and crowded positioning

What happened

The S&P 500 posted its strongest quarter of earnings growth since the post-pandemic boom. Blended earnings growth topped 50% in Q2 2026, 85% of companies beat estimates, and the average earnings surprise was 30.7%, about six times the historical norm. Despite this, stocks fell on both beats and misses. Barclays cited crowded positioning and growing scrutiny of AI capital expenditure as key drivers. Energy, technology, and communication services each had double-digit revenue growth. The price reaction was especially muted in technology and communication services, while energy gained more recognition.

Why it matters

The market is repricing AI-era earnings. Hyperscaler capital expenditure is absorbing 93-94% of operating cash flow in 2026, up from 33-40% three years earlier. If AI and data-center capex slows relative to expectations, Barclays estimates the S&P 500 could face a mid-single-digit EPS headwind and a 10-13% valuation de-rate. Investors should watch not just earnings beats, but evidence that AI spending is translating into realized revenue and free cash flow, and credible monetization timelines.