US stocks jumped sharply higher Friday, closing out the best week in two years and starting the second half on a solid positive note. In thin trade ahead of the long July 4 holiday weekend, the Dow Jones Industrial Average leaped 168.43 points (1.36 percent) to 12,582.77. The broader S&P 500 gained 19.03 (1.44 percent) to 1,339.67, while the tech-heavy Nasdaq Composite was up 42.51 points (1.53 percent) at 2,816.03. All 30 Dow blue chips were up, led by a 2.8 percent climb by Alcoa and a 2.2 percent jump by JP Morgan Chase. On the Nasdaq, Apple added 2.2 percent and Yahoo 2.8 percent. The markets got a boost from the release of the ISM purchasing managers index for the manufacturing sector for June, which climbed 1.8 percent from May, much better than economists had forecast. But that came after a sharp seven-percent drop in May from April, and the June index remained far below the level achieved in the first four months of the year. The ISM\'s new orders index rose just 0.6 percent in June, a suggestion of continuing fragility in the sector. There was also good news from the three big automakers, which all turned in solid June sales numbers: Chrysler sales jumped 30 percent, Ford 14 percent and General Motors 10 percent. Ford shares rose 1.7 percent while GM jumped 0.7 percent. Chrysler is not publicly traded. Specialty truck maker Oshkosh Corp soared 13.9 percent on news that raider Carl Icahn had accumulated a 9.5 percent stake in the company and reportedly plans to pressure management to deliver more to shareholders. Microsoft and Apple were up 0.1 percent and 2.3 percent respectively after their consortium paid $4.5 billion to beat out rivals Google and Intel for the valuable patent assets of bankrupt Nortel. Google was no worse for wear; its shares rose 2.9 percent, while Intel\'s rose 1.7 percent. Bond prices fell. The yield on the 10-year US Treasury note rose to 3.20 percent from 3.16 percent late Thursday while that on the 30-year bond edged upwards to 4.40 percent from 4.38 percent. Bond prices and yields move in opposite directions.