Wall Street's main indexes post gains with increases in Amazon.com shares and energy sector

Wall Street's main indexes posted gains yesterday, with increases in Amazon.com shares and the energy sector. Meanwhile, Treasury yields rose further and investors looked to economic data and Federal Reserve policymakers' remarks later in the week for clarity on the path for interest rates.         The Nasdaq Composite index gained half a percent, the S&P 500 rose 0.4 percent and the Dow Jones Industrial index slipped 0.1 percent.