U.S. stocks ended little changed on Monday in a quiet session, as investors saw little reason to continue buying on Wall Street after a winning streak of six days of the S & P 500, although the activity mergers and acquisitions boosted the energy sector. * The S & P 500 halted its longest streak profit since mid-April, after hitting session highs on Friday, with the Dow Jones. Investors await catalyst to continue the progress, but the upward trend is seen Wall Street largely intact. * Sales of U.S. existing homes rose in May at a rate more than double than expected, while the preliminary reading of manufacturing index hit its highest level since May 2010.