Scott Rubner, who leads the Equity and Derivatives Strategy team at Citadel Securities, revealed in his most recent research report that retail investors made net purchases of US stocks totaling US$9.1 billion last week. This figure represents the highest weekly net purchase volume in almost 15 years, with the bulk of the funds being funneled into stocks and ETFs linked to artificial intelligence (AI). Specifically, semiconductor stocks attracted a net investment of roughly US$2.6 billion, while stocks associated with AI infrastructure drew about US$2.4 billion. Rubner emphasized that this surge in buying activity reflects a heightened willingness among retail investors to take directional bets, rather than a mere uptick in overall trading volume. Notably, Rubner had earlier forecasted a resurgence of retail funds in the market come October. The latest data underscores that, despite apprehensions about an AI bubble, retail investors remain steadfast in bolstering their holdings within the AI and semiconductor sectors.