[Head of Castle Securities Equity: Retail investors are expected to return to the U.S. stock market and there will be a window to add positions in October] On October 2, Scott Rubner, head of equity and equity derivatives strategy at Castle Securities, said that after the sharp cooling in September, retail investors are expected to flood into the U.S. stock market again this month. Rubner wrote in a note to clients that while there may still be volatility in October, with the earnings season approaching and corporate stock buybacks about to resume, this month provides a better entry point for investors to "re-add positions." After positions were cleared and valuations fell, "the market entered the fourth quarter from a cleaner starting point, with significantly greater room to re-establish exposure," he said. Spot stock trading volume fell to 0.94 times the average over the past year in September, the lowest level in 2026, Rubner wrote. Retail option premiums also dropped by the same multiple. Current stock trading activity is 26% below its June high, and option premiums have shrunk by about one-third from the 1.41 times reached at that time.