The Dow Jones Industrial Average and S&P 500 Thursday vaulted to new records Thursday after Federal Reserve Chairman Ben Bernanke pledged to maintain the Fed's easy-money policy for the foreseeable future.
The Dow surged 169.26 (1.11 percent) to 15,460.92, well above the previous high of 15,409.39 on May 28. The S&P 500 gained 22.40 (1.36 percent) to 1,675.02, up from it prior record of 1,669.16 on May 21.
The Nasdaq Composite meanwhile added 57.55 (1.63 percent) to 3,578.30, its highest level since September 2000.
Bernanke, speaking in Boston late Wednesday afternoon, promised to keep interest rates low due to the weak economy, suggesting a slower time-frame to tapering the Fed's aggressive bond-buying program.
The comments surprised markets, which have been bracing for the Fed to scale back the bond-buying program as soon as September.
"I don't think there's any immediate Fed tapering in the future," said William Lynch, director of investments at Hinsdale Associates.
Lynch said markets are also hopeful that the upcoming earnings season will surprise to the upside, given that expectations are low.
Technology companies were among the biggest winners, including Apple (up 1.6 percent), Google (up 1.6 percent), Dow component Intel (up 3.2 percent) and Oracle (up 2.0 percent).
Semiconductor maker Advanced Micro Devices shot up 11.8 percent after Canaccord Genuity upgraded its recommendation to "buy," concluding the company's technology was well positioned to take advantage of the growing game-console business.
Microsoft jumped 2.8 percent after unveiling a reorganization that aims to unify strategy around diverse segments such as Windows, Windows Phone, Xbox, Surface, Office 365 and others.
Citigroup analysts said the change probably will not significantly affect near-term profits but could bolster long-term efforts.
Disney jumped 2.6 percent after a note from JPMorgan Chase said strong Disney TV and amusement-park operations would offset the weak performance of its expensive "The Lone Ranger" film, according to Dow Jones Newswires.
Bond prices rose on Bernanke's comments. The yield on the 10-year Treasury nosedived to 2.57 percent from 2.68 percent late Tuesday, while the 30-year fell to 3.62 percent from 3.69 percent. Bond prices and yields move inversely.