The stock markets in the United States gained today driven by investors' optimism regarding corporate earnings. The S&P 500 rose to as much as 2121.06 points during the early trading today, but eventually closed at 2,114.4p points. Sign up for our free newsletter According to Bloomberg, 73% of all the companies in the S&P 500 that already reported its quarterly earnings beat profit estimates while 49% outperformed sales estimates. Commenting on the market trends, Michael James, a managing director of equity trading at WedBush Securities told Bloomberg, "With nothing negative coming from overseas, you're seeing a continuation of the positive price action from Friday afternoon." James added that investors will probably focus their attention on the earnings results of a number of high-profile companies over the next several days. He said, "We still have a pretty heavy slate of earnings this entire week." On the other hand, Bill Nichols, head of U.S. equities at Cantor Fitzgerald told Dow Jones Business News, "Now the question is if the market can truly break out to new highs. History has shown recently that you sell this rally. The S&P 500 reached an all-time closing high of 2,117.69 on April 24. Investors are closely watching economic data to look for signs regarding timing interest rate hike by the Federal Reserve. The Institute of Supply Management ISM recently reported that the manufacturing sectors expanded in April. The PMI registered a 51.5% while the new orders index was 53.5%. The Department of Labor reported that the number of American workers who applied for unemployment benefits declined 34,000 to 262,000 for the week ended April 25. The agency is scheduled to release its monthly jobs report on Friday. Economists estimated that the economy added 225,000 non-farm jobs and the unemployment rate declined to 5.4% in April.