Big investors, fearful of September's typical seasonal declines, exited profitable stock positions on Tuesday, according to investors and trading company research, a sign the selloff in tech may be driven by a broad aversion to risk. The tech-heavy Nasdaq and broad S&P 500 stock index sold off sharply on Tuesday, driven by tech stocks that have rallied hard for much of the year. Nvidia sank 3.5%, the biggest drop in nearly four months. "This week's tech sell-off looks less like panic and more like a broad reshuffling of risk," said Bruno Schneller, managing director at investor Erlen Capital Management. "We've seen crypto, high-beta tech and the AI beneficiaries all come under pressure at the same time, which suggests investors are cutting exposure across multiple risk assets rather t