AP, May 30 / PRNewswire-FirstCall-Asianet /-- according to Vanda Research, a research firm that tracks retail trading flows in the United States, institutional investors are the main driver of AI stock buying in the recent US stock market, while individual investors, as important participants in the financial market, have not bought large amounts of AI shares. "our internal positions in US stocks show that retail investors remain on the sidelines despite the recent AI boom," Vanda Research said in a report last week.