The recent move has even unwound a popular stock market trade this year that involved buying shares of chipmakers, which are the biggest beneficiaries of the flood of spending on AI, and shorting software firms, which are considered at risk from the technology. Over the past month that has reversed, with the S&P North American Expanded Technology Software index leaping 19 per cent since its July 23 low, while the Philadelphia Stock Exchange Semiconductor index, or SOX, is down 4.9 per cent over that stretch.