The Globe and Mail reports in its Wednesday edition that Canada's main stock market index fell on Tuesday to start the new month on a cautious note, weighed by losses for metal-mining shares as investors worried about an uncertain outlook for some major economies including China. A Reuters dispatch to The Globe says that the S&P/TSX Composite Index ended down 93.71 points at 20,532.93, after posting its highest closing level in three months in the previous session. The S&P 500 and Nasdaq also closed lower. "We are overbought and we're pulling back," said Robert McWhirter at Selective Asset Management. "Everybody is still scratching their head about China." Global factory activity remained in a slump in July, private surveys showed, a sign slowing growth and weakness in China were taking a toll on the world economy, including Canada's. Canadian manufacturing activity slowed for the third straight month in July. The materials group lost 1.8 per cent as gold and copper prices fell. Shares of Silvercrest Metals were particularly weak, plunging 21.5 per cent after two brokerages cut their price target on the stock. Heavily weighted financials fell 0.6 per cent. Toronto notched a gain of 2.3 per cent in July.