US stocks surged to new multi-year highs Thursday helped by positive economic data and the European Central Bank's new plan to help ailing eurozone countries in the bond market.
The S&P 500 and the Dow both registered their best closing levels since December 2007, holding onto strong gains achieved as soon as the markets opened.
Banks led the march higher, with Bank of America putting on 5.0 percent and JPMorgan Chase gaining 4.3 percent.
Key tech stocks also registered strong gains, with Microsoft rising 3.1 percent, Google adding 2.7 percent, and Cisco surging 4.4 percent.
The boost came ahead of the release of important jobs numbers Friday, and set a positive background for President Barack Obama's much-awaited address Thursday night to the Democratic Party's convention, kicking off the final stretch of the presidential race.
Obama, harried by charges he has not done enough for the economy, is running neck and neck with Republican rival Mitt Romney.
The Dow Jones Industrial Average finished up 244.52 points (1.87 percent) at 13,292.00.
The S&P 500-stock index advanced 28.68 (2.04 percent) to 1,432.12, while the tech-heavy Nasdaq jumped 66.54 (2.17 percent) to 3,135.81.
Markets took off from the opening bell and pushed higher as the ECB confirmed its bond market intervention plan, a program aimed at lowering the borrowing costs of the eurozone's economically weaker governments and, ultimately, shoring up the eurozone.
The ECB plan "is another step in the right direction that could restore confidence in the euro," said Jason Schenker at Prestige Economics.
"It may not be the ideal solution, but ECB and eurozone member political will appears resolute."
Also helping was encouraging data showing growth picking up modestly in the US services sector and, tentatively, improvement in the jobs market.
The Dow's 30 blue chips were all in the positive: General Electric added 3.2 percent, Caterpillar 2.5 percent, and Intel 2.9 percent.
Amazon jumped 2.1 percent as it unveiled a larger Kindle Fire tablet, taking on the Apple iPad. Apple, the world's largest company, market capitalization-wise, was a laggard for the day, rising just 0.9 percent.
Also on the Nasdaq, eBay gained 3.7 percent while Seagate was a rare loser, shedding 2.6 percent after getting a rating cut from analysts at Needham & Co.
Facebook joined the surge, rising 2.1 percent.
Bond prices tumbled. The yield on the 10-year Treasury leaped to 1.67 percent from 1.59 percent Wednesday, while the 30-year yield rose to 2.80 percent from 2.70 percent. Bond yields move inversely to prices.