Stocks have kicked off the new week in a big way so far, as the Dow Jones Industrial Average (^DJI -0.65%) was up more than 136 points as of 2:30 p.m. EDT. All but a few of the blue-chip index's member stocks were in the green today. Microsoft (MSFT -1.96%) has impressed as of late, with the tech stock gaining 2.7% to lead the Dow today. Meanwhile, health care is making waves around the market with big news out of Dow member Pfizer (PFE 0.19%). Let's catch up on what you need to know.

Is Europe stimulus on the way?
Hope is rising around investment circles over the potential for stimulus moves from the European Central Bank. The ECB won't budge on its monetary policy when it meets later this week, but downbeat inflation statistics across Europe have engendered thoughts that the central bank might pull the trigger on action sooner rather than later. The eurozone's inflation fell to 0.5% in March, down from February's 0.7% and falling just below economist predictions. This is the third-straight month of decline; with the ECB targeting near-2% inflation -- and with Europe desperate to climb out of its economic doldrums -- it's worth keeping an eye on whether the central bank takes a harder stance on jump-starting its economy.

Microsoft CEO Satya Nadella. Source: Wikimedia Commons, Leweb Photos

Microsoft has capitalized on a different sort of optimism today. Investors continue to rally around the company's recent moves under new CEO Satya Nadella, as Microsoft's release of Office for Apple's iPad led to the Word app reaching the App Store's sixth overall spot in its chart of highest-grossing apps. While the move may not be great news for the allure of Microsoft's own competing tablet, the Surface, it shows Nadella's willingness to marry Microsoft's best products with the tech world's giants.

Microsoft isn't out of the game in the mobile hardware business by any means, either: The company expects to close its acquisition of Nokia's mobile division next month, and Nadella's potential to introduce more of a mobile edge to Microsoft's portfolio offers tantalizing possibilities to the company's future.

Pfizer, up 0.72%, is following up on a very active week last week with another big announcement that came late in the day on Friday. FDA regulators approved Pfizer's nonprescription version of AstraZeneca's (AZN -0.29%) strong-selling acid reflux therapy Nexium, which should enable Pfizer to rake in big sales for its over-the-counter drug business.

Pfizer purchased the rights to the over-the-counter Nexium 24HR for $250 million two years ago from AstraZeneca, but it's not a complete loss for the latter. AstraZeneca will pull in royalties from Pfizer's sales, although that won't be much of a relief to investors concerned about Nexium's patent loss this May, a real danger for AstraZeneca considering the drug made more than $3.8 billion last year. Pfizer won't make anywhere near that much with its over-the-counter version, but it's still a worthy addition to an expansive drug portfolio.