U.S. stocks rallied on Monday, with the S&P 500 crossing 2,000 for the first time, lifted by a round of corporate deals and optimism that the European Central Bank would embark on further moves to stimulate the European economy.

"I've got the bottle ready to open," said Howard Silverblatt, senior index analyst at S&P Dow Jones Indices, referring to a 1998 Dom Perignon champagne that he plans to pop when the S&P 500 finishes above the milestone.

"Closing above 2,000 would be a bit more significant because then you can bounce from there; it gives people a sense of confidence more than anything else; it's a psychological mark, not a technical mark," said JJ Kinahan, chief strategist at TD Ameritrade.

"It's important that we made it; it's a milestone, but more importantly is it's a good time to review where you've been and where you're going; that's the true take away for the individual, as institutions should be doing it anyway," said Silverblatt.

Remarks Friday by ECB President Mario Draghi at the Jackson Hole, Wyoming, meeting of central bankers heightened expectations of additional policy easing.



Monday's gains are largely due to "Mr. Draghi's comments, his assurances that the European Union is as dedicated to keeping their markets as healthy as we are, it gave the market an excuse to test that 2,000 level," said Kinahan.

'Groundbreaking' Draghi brings cheer to markets



Burger King Worldwide is in talks to combine with Tim Hortons and moves its headquarters to Canada. Switzerland's Roche Holding has agreed to acquire U.S. biotechnology company InterMune for $8.3 billion in cash.