S&P 500 ex-AI stocks outperform full index by 6.4 points in October amid AI spending concerns

S&P 500 ex-AI stocks have outperformed the full index by 6.4 percentage points in October 2026, with the gap widening to a record high after three weeks of selling. Chipmakers led losses in AI-linked firms due to financing worries and higher rates, while money rotated into energy and consumer staples. The record margin sits above the previous monthly high of 3.6 points set in July.