The Globe and Mail reports in its Friday edition that the S&P 500 and Nasdaq ended sharply lower Thursday, weighed down by a slump in chipmaker Nvidia after its quarterly report failed to rekindle Wall Street's AI rally, while investors focused on data pointing to a cooling U.S. economy. A Reuters dispatch to The Globe says that Canada's main stock index was also lower, despite stronger-than-expected earnings from three banks. Nvidia tumbled 8.5 per cent, evaporating $274-billion (U.S.) in stock market value, after the Silicon Valley company gave a weaker-than-expected quarterly forecast for gross margin that overshadowed an upbeat revenue outlook. "Nvidia's earnings were good, but not like the blockbuster earnings that they've been delivering for a while," said Scott Welch, at Certuity. The S&P/TSX Composite Index ended down 200.12 points at 25,128.24, wiping out its gains over the previous three days. "Markets are going to be in very uncertain territory for some time here," said Michael Sprung, president at Sprung Investment Management. Donald Trump said his proposed 25-per-cent tariffs on Mexican and Canadian goods will go into effect on March 4 and threatened an extra 10-per-cent duty on Chinese imports.