The Globe and Mail reports in its Friday edition that U.S. and Canadian stocks closed in negative territory on Thursday, with a resumption of Tuesday's tech sell-off as investors contended with mounting economic uncertainty and stretched valuations. A Reuters dispatch to The Globe says that all three major U.S. equity indexes lost ground as risk appetite was dampened by worries over inflated stock prices, particularly from artificial-intelligence-related momentum shares. The Philadelphia SE Semiconductor index dropped 2.4 per cent. The tech sector was also a notable decliner in Toronto, falling 3.3 per cent. "Valuations are still very much a concern longer term, but the market is still bullish," said Paul Nolte, at Murphy & Sylvest in Elmhurst, Ill. "That buy-the-dip mentality is still there." On the downside, the U.S. suffered a 183.1-per-cent surge in monthly layoffs, the worst October in more than two decades. The Dow fell 397.35 points to 46,913.65 and Nasdaq lost 445.80 points to 23,053.99. The S&P/TSX Composite Index was down 234.89 points at 29,868.59. Other than modest gains in materials and utilities, all major sectors were lower. Industrials was also a significant decliner, losing just over 2 per cent.