Canadian stocks experienced gains following the news about new European treaty aimed at strengthening fiscal regulations in the euro-zone. The S&P/TSX Composite Index added 165.88 points to 12,240.97, after slight losses on Friday. The S&P/TSX Capped Diversified Metals and Mining Index increased by 4%, the S&P/TSX Capped Energy Index gained 2.2% and the S&P/TSX Capped Industrials Index increased by 1.8%.