NEW YORK ( TheStreet) -- Major U.S. stock markets jumped Thursday, driving the S&P 500 and Dow Jones Industrial Average to new closing and intra-day highs after a spate of upbeat earnings reports led by UnitedHealth ( UNH), and Federal Reserve Chairman Ben Bernanke told Congress the central bank was staying its course on stimulus. The S&P 500 gained 0.5% to 1,689.37 after trading as high as 1,693.12 . The advances bring the index's year-to-date gain to 18.5%. The Dow Jones Industrial Average jumped 0.5% to 15,548.54 after touching an intraday high of 15,589.40 while the Nasdaq was little changed at 3,611.28. UnitedHealth rose 6.5% to close at $70.55 after the health insurer beat second-quarter expectations by 15 cents at $1.40 a share after enrollment accelerated and the company raised the lower end of its full-year earnings outlook. Google ( GOOG) and Microsoft ( MSFT) reported their quarterly results after the closing bell. In the regular trading session, Google was off 0.86% to $910.68 and Microsoft lost 0.84% to $35.44. Johnson Controls ( JCI ) surged 8.3% to $40.43 after the maker of heating and ventilation systems for buildings forecast fourth-quarter earnings that exceeded the Wall Street target of 92 cents a share at a range of 93 cents to 95 cents a share. On the downside, Amphenol ( APH) was the biggest percentage loser on the S&P after the fiber-optic connector maker reduced its profit and sales forecasts for 2013. Shares dropped 9.7% to $76.35. IBM ( IBM) gained 1.8% to $197.99 after the computer services giant beat Wall Street's second-quarter earnings estimates while raising its guidance despite missing analysts' top-line forecasts. Excluding the impact of a $1 billion work force rebalancing charge incurred in the quarter, IBM earned $3.91 a share, a year-over-year increase of 8%. In financial services, Morgan Stanley ( MS) added 4.4% to $27.70 after the New York-based bank reported that profits rose 69% in the second quarter on higher revenue on the back of strong equities trading results and a solid performance in a difficult quarter for fixed income. Equity sales and trading net revenues of $1.8 billion up from $1.3 billion a year ago. Investor sentiment on Thursday was also bolstered by the employment outlook as initial jobless claims fell 24,000 to 334,000 in the week ended July 13, according to the Labor Department. Additionally, the Philadelphia Fed's Business Outlook Survey showed substantial improvement in manufacturing conditions within the Philadelphia Federal Reserve district in July, jumping to 19.8 from 12.5 in June. Economists were expecting a decline to 7.8. And last but not least, the Conference Board's Leading Economic Index for the U.S. was unchanged in June, remaining at 95.3, following a 0.2% increase in May, and a 0.8% rise in April. A gain of 0.3% in June was expected. The benchmark 10-year Treasury was plunging 14/32, pushing the yield up to 2.545%. Follow @atwtseWritten by Andrea Tse and Joe Deaux in New York >To contact the writer of this article, click here: Andrea Tse.>.