Retail Investors Mount Biggest AI Stock Rally in 15 Years as Sentiment Swings Back

Retail investors surged back into artificial intelligence stocks with a record $9.1 billion in net purchases during the week ending October 14, 2026—the largest single-week inflow in 15 years—signaling a sharp reversal after months of caution about soaring valuations in the AI sector. The rebound was concentrated in semiconductors and AI infrastructure, with $2.6 billion flowing into chip stocks and $2.4 billion into AI infrastructure plays, according to Citadel Securities data. This buying spree came after September's dramatic withdrawal, when retail traders pulled back sharply as trading volumes reached their lowest point of 2026.